Paeonia species key

This key will help you identify your paeonia species. Natural peony populations tend to show a great deal of variability, so they are difficult to describe and you may find that a plant in one population of a species might also fit in with another species; the descriptions are based on averages. Keep in mind that most paeonia species in the garden are probably hybrids. If you want to change an answer to the questions along the way, please refresh the whole page and restart, sorry for that, but this is due to technical reasons. The key is based upon Hong De-Yuan “Peonies of the World”, but added upon from other sources as mentioned each time. Some more subspecies and new species along with more images will be added as time permits.

The genus paeonia

A perennial dies back above ground each year and grows from below ground buds in Spring. A shrub has woody stems and will start new growth on this in Spring. Another difference between herbaceous and shrubby peonies is the disk. The disk is a flat, circular plate below the carpels. In herbaceous peonies this disk can be visible or not, but is always simply below the carpels. In shrubby peonies it goes upwards, surrounding the carpels partly or whole, and is then called a sheath.

Paeonia ludlowii


Deciduous and caespitose shrubs, up to 3.5 m tall, glabrous throughout. Roots attenuate downward, not fusiform. Stems grey, up to 4 cm in diameter. Shoots green, with 8-12 scales at the base. Lower leaves biternate, green above, pale glaucous beneath; petioles 8-18 cm long; leaflets 9, lateral 3 leaflets on each side with main petiolules 2-3.5 cm long, terminal 3 leaflets with main petiolules 5-11 cm long; leaflets nearly sessile, but not decurrent, 6—19 cm long, 5—15 cm wide, 3—segmented to halfway or nearly to the base; segments 4—12 cm long, 1.5—5.5 cm wide, mostly 3—lobed to the middle; lobes 2—5 cm long, 0.5—2.5 cm wide, entire or with 1 or 2 teeth, segments, lobes, and teeth all acuminate at the apex. Flowers 3 or 4 on each shoot, both terminal and axillary, with the terminal one blooming first, forming a cyme; pedicels slightly curved, 5-14 cm long, naked or with a leafy bract; involucrate bracts 4 or 5, green; sepals 3 or 4, grading into one another, all or all except one caudate at the apex; petals pure yellow, spreading, obovate rounded at the apex, 4—5.5 cm long, 2.5-3.5 cm wide; filaments yellow, 1.1—1.5 cm long, anthers yellow, c. 4 mm long; disk fleshy, 1 mm high, yellow, waved; carpels mostly single, very rarely 2; stigmas sessile, yellow. Follicles cylindrical, 4.7—7 cm long, 2—3.3 cm in diameter. Seeds kidney-shaped, dark brown, c. 1.5 cm long, 1.2 cm in diameter.

Chromosome number: 2n=10 (diploid).

Paeonia ludlowii was collected from sparse forests and thickets, on granites at altitudes of 2,870—3,450 m. This is a narrow endemic in southeastern Xizang (Tibet) and known from Nyingchi, Mailing, and Lhünzê counties at 28.4—29.9°N, 92.4—94.8°E.

This species is also a medicinal plant and is often dug out by local people for its root bark. In three of the five populations studied (D. Y. Hong et al. H96007, H96014, H96030), hundreds of individuals were dug out by people from Gansu and Qinghai provinces (Hong, 1997). This has caused a serious threat to the survival of this species. Effective measures must be taken to conserve this beautiful flower.

In the description of Paeonia lutea var. ludlowii, Stern and Taylor (1951, 1953) indicated that the taxon was distinctly different from the variety lutea, distinguished by its long, commonly unbranched stems to 8 feet (2.4 m) vs. 5 feet (1.5 m) in var. lutea, its larger and more open flowers, with up to 2 carpels that are twice as large as those of var. lutea. These differences have been confirmed upon examination of plants in five populations in Mailing and Nyingchi counties and five populations of var. lutea (= P. delavayi). As shown in Hong (1997), plants of P. ludlowii are tall from a caespitose base, and have relatively large, pure yellow flowers, yellow filaments, acuminate leaf segments and lobes, and typically one carpel per flower (more than 97% of the flowers examined had a single carpel and fewer than 3% had two). Furthermore, P. ludlowii produces very large follicles that contain the largest seeds in the genus. By contrast, plants of P. delavayi are not caespitose and have much shorter stems, acute leaf lobes and segments, smaller flowers, yellow petals that are nearly always red-blotched at the base, purple-red filaments, and three or four, rarely two, much smaller carpels. These differences clearly support the recognition of the variety ludlowii as a distinct taxon and species.

Paeonia ludlowii is a tall shrub that often forms large and dense clumps with dozens of stems. A single individual can have up to 105 flowers (Hong, 1997). All of the five populations studied were small in area, and the largest population was about 200 m in diameter. Except for the Quenima Village population (D. Y. Hang et al. H96020), which had only four individuals, all the populations observed consisted of many rather densely packed individuals, and the species was a dominant element in the community. Two factors may explain the small population areas that contain a large number of individuals. First, this species has a high seed-set, and its seeds appear to have a high germination rate. Nearly 100 seedlings were found in an area of a square meter under a large individual in the Nanyigou population (D. Y. Hang et al. H196030). Second, the seeds of P. ludlowii are large (ca. 1.2 cm diameter) and are not adapted to long-distance dispersal; perhaps they are mostly moved by rats. The species is obligately sexual, and no vegetatively produced individuals or plantlets have been found in any of the populations. More than 20 small plantlets were dug out, and all were found to be seedlings, a sharp contrast to P. delavayi, which reproduces both sexually and vegetatively.

 

The Peony Society also has a page about this species here.

If you need more info about paeonia species, click here.

Kew Plants of the world lists accepted species and synonyms: here.

Source:
Hong, De-Yuan. “Peonies of the World. Taxonomy and phytogeography.” Kew: Royal Botanic Gardens, 2010, pp. 61-64.

Paeonia delavayi


Shrubs 0.2—1.8 m tall, glabrous throughout. Roots tuberous with tubers up to 8 cm long, 2 cm in diameter. Stems grey, 1.5 cm in diameter, shoots green, sometimes pink, with 5-9 yellow or pink scales at the base, simple but often with sterile branches in axils, occasionally branches developed and flowering. Petioles 10—22 cm long; lower 2 or 3 leaves biternate or ternatepinnate, ovate in outline, 15—30 cm long (excl. petioles), 10—22 cm wide; leaflets 9, more—or—less decurrent, first divided into 3—11 primary segments; segments divided again mostly to near the base or halfway into 2—11 secondary segments, thus each lower leaf with (17-)40-100(-312) segments; petiolules of middle primary divisions 5-9 cm long, petiolules of lateral primary divisions 1-3 cm long, petiolules of secondary divisions much shorter; segments linear, linear-lanceolate, entire or occasionally lobed, 1.5—10 cm long, 0.5—4.5 cm wide; lobes similar to segments but shorter; segments and lobes acute at the apex. Flowers usually 2—3 on a shoot, terminal and axillary, forming a cyme, less frequently solitary and terminal, occasionally 4, more-or-less pendulous, the terminal one blooming first, the third one from the top second, the fourth from the top the third, whereas the second from the top blooms last; involucrate bracts 1—5, leaf-like, the outer ones 2—4—segmented, green; sepals 2—9 in number, green outside, green but pink at the base inside, or entirely purple or purple-red, rounded or triangular-rounded, mostly caudate, rarely rounded at the apex. 1.3—3.7 cm long, 0.6—2.3 cm wide; petals 4—13, but mostly 7-11 in number, yellow, yellow with a red or purple—red spot at the base, red, dark red, or dark purple—red, sometimes white, orange, green-yellow, or yellow with red margins; stamens 25—160; filaments yellow, pink, red, or dark purple-red; anthers yellow, pink, red, or dark purple-red; disk fleshy, short, annular or short-cylindrical, 1—3 mm high, incised, green, yellowish, yellow, red or dark red; carpels 2-4, very rarely 6-8; ovaries usually green, sometimes purple; stigmas sessile, yellow-green, yellow, red or purple-red; ovules 7—17 per carpel. Follicles oblongovoid, 2—4 cm long, 1-1.5 cm wide, brown at maturity. Seeds 1—6 in each follicle, brown-black, oblong, c. 10 mm long, c. 8 mm in diameter.

Chromosome number: 2n = 10 (diploid).

Paeonia delavayi was collected at altitudes from 1,900 to 4,000 m, primarily in sparse thickets or dry Pinus and Quercus woods, rarely on grassy slopes or glades of virgin Picea forests. The taxon is endemic to China and restricted to western Sichuan, eastern Xizang (Tibet) and Yunnan.

Plants of Paeonia delavayi are always dwarf shrubs. The tallest plants (ca. 1.8 m) were found in Yunshanping, Lijiang, northwestern Yunnan (D. Y. Hong et al. H97103), where they grew in Picea likiangensis (Franch.) E. Prit. forest at altitudes of c. 3,200 m. By contrast, the shortest plants (rarely reaching 1 m) were found in Ganghaizi, Lijiang (D. Y. Hong et al. H97095), about 20 km SE of the Yunshanping population, growing in dry, sparse Pinus densata—Quercus spinosa forest. Many dwarf individuals had woody parts underground, and only annual shoots emerged above ground. Plants of the other populations that we studied were intermediate between these two.

Although the leaves of Paeonia delavayi are biternate or ternatepinnate, the leaf segments are quite variable in number, length and width. The number of segments ranged widely from 17 to 312 (Hong et al. 1998), and seemed to differ between populations. For example, segment number varied from 17 to 49 in the population D. Y. Hong et al. H96024 (A, K, MO, PE, US), and from 68 to 312 in the population D. Y. Hong et al. H95063 (A, K, MO, PE, US). However, the standard deviation of the variation in number of leaf segments (Hong et al. 1998) shows that these two populations are just the extremes of a wide range of variation that was also observed within given populations. Taking all the populations into consideration, the number of segments varied continuously in this species. Paeonia potaninii was described as new by Komarov in 1921 because it was considered to have narrower leaf segments than P. delavayi. However, the width of leaf segments also varies greatly, ranging from 0.4 to 2.8 cm within P. delavayi, and from 0.76 to 1.83 cm in the population D. Y. Hong et al. H95070 (PE) from the type locality of P. potaninii. The D. Y. Hong et al. H95070 population falls in the middle of the overall variation ranges for leaf-segment width (Hong et al. 1998) and length in this species. Therefore, it is evident that P. potaninii is similar to P. delavayi in this respect.

Stern (1946) distinguished Paeonia delavayi from its allies by the presence of a conspicuous involucre immediately below the calyx. Across the genus, however, it is difficult to distinguish clearly between involucrate bracts and sepals, and there is also a gradation between leaves and involucrate bracts. We designate the laminae borne some distance below the flowers as leaves, and those at the top of shoots and immediately below the calyx as involucrate bracts. lnvolucrate bracts, so designated, have various forms, ranging from segmented and leaf-like to entire and sepal-like. The sepals have a much broader proximal part and a dark green, smaller and narrower distal part that has a mucronate or rounded apex. The total number of bracts and sepals varies greatly both within and between populations of P. delavayi. The population D. Y. Hong et al. H97103 (A, K, MO, PE, US), with dark red flowers, at Yunshanping, Lijiang, which corresponds to the type locality of P. delavayi (Stern 1946), indeed had the highest number of bracts and sepals (10 or 11) forming the so-called conspicuous involucre, whereas other populations observed by us had fewer bracts and sepals. However, the difference was not significant (Hong et al. 1998). Another population D. Y. Hong et al. H97095 (A, K, MO, PE, US), only about 20 km from H97103, was variable in number of both bracts and sepals, and some flowers had 10 or 11 bracts and sepals (Hong et al. 1998), similar to those in the H97103 population. The same total number of bracts and sepals were found in these populations and in D. Y. Hong et al. H97087 (A, K, MO, PE, US), which had pure yellow or yellow petals with a dark red blotch at the base. Plate 1 in Hong et al (1998) and the remarks above demonstrate clearly that there is a continuous variation in the number of bracts and sepals, and that no correlation exists between petal colour and the total number of bracts and sepals. Therefore, P. delavayi cannot be separated from P. potaninii, P. lutea, P. trollioides and similar names.

Variation in the number and colour of floral parts extends to the sepals, which vary in colour both on a single flower and within populations (Hong et al., 1998). They are usually green, but sometimes dark red or purple (Hong et al., 1998). In addition, the sepals vary greatly in size both within and between populations, and the variation was seen as continuous (Hong et al., 1998). Although population H97103 from Yunnan had larger sepals than other populations, the formation of a conspicuous involucre is not unique in this species as alleged by Stern (1946).

Petal colour has been much emphasised in the taxonomy of the Paeonia delavayi complex, used by various authors (Finet & Gagnepain, 1904; Stern, 1946; Fang, 1958) in distinguishing the yellow corollas in P. lutea from the dark red ones seen in P. delavayi. As shown by Hong and his co-workers (Hong et al. 1998), petal colour is extremely variable between and within populations (Hong et al. 1998). In the populations D. Y. Hong et al. H97112 and H97128 from Xianggelila, Yunnan, various petal colours appeared, and a few individuals in the latter population even had white petals. On the basis of the literature and our own observations, red, dark red or dark purple-red petals occur in the northeastern portion of the distributional range, while yellow petals or yellow petals with a dark red spot at the base were found in the northeast, west, and south. Therefore, petal colour is very variable within a given region or population, showing only a weak geographical differentiation, and is not correlated with other characters. Furthermore, petal colour was extremely variable in populations such as H97112 and H97128, both from northwestern Yunnan.

Unlike the floral disk of the other species of sect. Moutan, the disk in Paeonia delavayi and P. ludlowii is generally short and fleshy. In the populations H97112 and H97119, the disk secreted abundant nectar in some flowers, and it seems likely that this secretion made these flowers more scented. The disk, including the incised teeth, varied in height from 1 to 3 mm, and in colour from pale yellow or yellow to red, even within a single population (e.g. H97112). Therefore, these disk characters are also of little, if any, taxonomic importance in this group.

Paeonia delavayi has the widest geographical range in section Moutan. The plants predominantly reproduce vegetatively, and cloning by stolons (Hong et al., 1998) was commonly seen in every population visited except for the population D. Y. Hong et al. H97103 (A, K, MO, PE, US) in Picea likiangensis forest in Yunshanping, Lijiang, Yunnan. Vegetative reproduction probably predominates in P. delavayi, and seedlings were very rarely found in the field. It was even more predominant at the northwestern and northern boundaries of the distributional range. In Yajiang County, in western Sichuan, the population H95070 was found near a village, where some individuals were growing by fences and on newly stabilised debris. In this population, only about 50% of the follicles were developed and, because of insect damage, only 20% had seeds. Cloning by stolons, however, was common. Additionally, examination in the spring of 1996 of all follicles from the five populations in Xizang (Tibet) produced in 1995 found no seeds. No follicles were observed in a population (from temple ruins in the village of Xituan, Gengzhanglungba Valley, Nyingchi County, Xizang (Tibet)) that consisted of numerous individuals over an area of about 250 m2. This population probably developed from individuals produced by cloning. Clonal growth by stolons was found in every population visited (Hong et al., 1998). The roots of P. delavayi are always fusiformly thickened (Hong et al., 1998). Such roots and stolons probably make the species more adapted to open, somewhat dry and disturbed habitats, and enable the species to establish rapidly forming a new population. It may also account for the scattered distribution of the species and the large number of individuals in any given population. Paeonia delavayi (var. lutea) has been listed as an endangered species in the China Plant Red Data Book (Feng in Fu & Jin, 1992). On the basis of its vegetative reproduction and relatively wide distribution, however, it is reasonable to conclude that this species will not become extinct so long as wanton digging is controlled (Hong et al., 1998, 2003).

 

The Peony Society also has a page about this species here.

If you need more info about paeonia species, click here.

Kew Plants of the world lists accepted species and synonyms: here.

Source:
Hong, De-Yuan. “Peonies of the World. Taxonomy and phytogeography.” Kew: Royal Botanic Gardens, 2010, pp. 66-71.

P. decomposita and P. rotundiloba are much alike and used to be subspecies within P. decomposita.

Paeonia decomposita


Shrubs to 1.8 m tall, glabrous throughout. Stems up to 2 cm in diameter. Lower leaves mostly triternate-pinnate, ternate-bipinnate, biternate-bipinnate, with 29—65 leaflets; terminal leaflets elliptic to orbicular, 3-partite to the base or 3-fid, terminal lobes 3-lobed; lateral leaflets elliptic to orbicular, 3-lobed or coarsely toothed. Flowers solitary, terminal, 10—15 cm wide. Involucrate bracts 2—5, mostly 2 or 3, unequal, linear-lanceolate. Sepals 3—5, green, broadly obovate, all caudate at the apex. Petals 9—12, rose, obovate, 4-7 cm long, 3—5 cm wide. Disk leathery, enveloping half of carpels at anthesis, white or yellowish, with triangular teeth. Carpels always 5, very rarely 4 or 3, glabrous, green or purple; styles 1—2.5 mm long; stigmas red. Follicles black-brown when mature, ellipsoid. 2-4 cm long, 1.3—1.7cm in diameter. Seeds black, glossy, broadly ellipsoid or globose, 8—10 mm long, 6—8 mm in diameter.

Chromosome number: 2n = 10 (diploid).

Paeonia decomposita was observed to grow in thickets, young secondary forests or sparse coniferous forests with Cotoneaster soongaricus (Regel) Popov, Rosa willmottiae Hemsl., Berberis polyantha Hemsl., and Cupressus chengiana S. Y. Hu, as well as species of Lespedeza, Rhamnus L. and Quercus L., on cliffs and rocks at altitudes firom 2,050 to 3,100 m. This species is confined to the Dadu River Valley of northwestern Sichuan in China.

The Peony Society also has a page about this species here.

If you need more info about paeonia species, click here.

Kew Plants of the world lists accepted species and synonyms: here.

Source:
Hong, De-Yuan. “Peonies of the World. Taxonomy and phytogeography.” Kew: Royal Botanic Gardens, 2010, pp. 12.

Paeonia rotundiloba


Shrubs up to 2.5 m tall, 3 cm in diameter at the base, glabrous throughout. Stems grey-black. Lower leaves mostly biternate-pinnate or ternate-pinnate, with 19-39 leaflets; leaflets not decurrent; terminal leaflets rhomboid to orbicular, 2.1-5.5 cm long, 1.5-4.8 cm wide, 3—partite to the base or 3-fid, terminal lobes 3—lobed. Flowers solitary, terminal, 10-15 cm broad. Involucrate bracts 2-5, mostly 2 or 3, unequal in size, linear-lanceolate or broad-elliptic, lobed or segmented. Sepals 3-5, green, broadly obovate or nearly orbicular, unequal in size, 1.5-3 cm long, 1.5-2.5 cm wide, all caudate at the apex. Petals obovate or oblong, incised at the apex, 3.5-6.5 cm long, 2-4.6 cm wide. Disk leathery, pale yellow, enveloping carpels nearly to the base of style at anthesis, 8-15 mm high, with triangular teeth. Carpels mostly 3, less often 2 or 4, very rarely 5; styles 1-1.3 mm long; stigma red. Follicles brown or grey—brown when mature, ellipsoid, 2.2-3.5 cm long, 1.2-1.6 cm in diameter. Seeds black, glossy, broadly ellipsoid or nearly globose, 8-10 mm long, 6-8 mm in diameter.

Chromosome number: 2n = 10 (Hong et al., 1988).

Paeonia rotundiloba occurred in well-developed thickets, young secondary forests or sparse Cupressus chengiana forests, often associated with Rosa multibracteata Hemsl. & E. H. Wilson, Cotoneaster soongaricus Popov, Ostryopsis davidiana Decne, Cotinus coggygria Scop., as well as species of Quercus L., Rhamnus L., Ribes L. and Spiraea L., etc. The subspecies was usually found on rocks at altitudes of 1,700—2,700 m. It is restricted to Minjiang Valley of northwestern Sichuan and Tewo County of SE Gansu, China, isolated from Paeonia decomposita by the Qionglai Range, which reaches over 4,000 m in altitude.

This species differs from P. decomposita in having much wider leaflets that are ovate-orbicular, lobes also wider, with terminal ones acute at the apex, and carpels mostly three to four, less frequently two or five in number.

It is worth noting here that Hong’s second book “Polymorphism and diversity” lists P. rotundiloba as a species, whereas in his first “Taxonomy and Phytogeography” it was listed as a subspecies of P. decomposita. This is because he raised the former Paeonia decomposita Hand.-Mazz. subsp. rotundiloba D. Y. Hong to specific status under the name Paeonia rotundiloba (D. Y. Hong) D. Y. Hong. The new species is distinguished from P. decomposita in having carpels mostly 3, less frequently 4 or 2, very occasionally 5 (rather than nearly always 5) and disk 8—15 mm high (rather than 4-9.6 mm high). In addition, there are differences in the number of leaf segments and in the shape of the terminal leaf segment. He regrets that he did not pay enough attention to the former two characters when he prepared the first book.

The Peony Society also has a page about this species here.

If you need more info about paeonia species, click here.

Kew Plants of the world lists accepted species and synonyms: here.

Source:
Hong, De-Yuan. “Peonies of the World. Polymorphism and diversity.” Kew: Royal Botanic Gardens, 2011, p. 15.

Paeonia qiui


Shrubs up to 1.2 m tall. Roots up to 2 cm in diameter, cylindrical, attenuate downwards. Stems grey or brown-grey, longitudinally striate. Lower leaves biternate, always with 9 leaflets; leaflets often reddish above, mostly ovate, less frequently ovatelanceolate or ovate-orbicular, rounded at the base, obtuse or acute at the apex, mostly entire, sometimes terminal leaflets shallowly 3-lobed, 4-12 cm long, 2—8 cm wide, usually glabrous above, densely villose at axils of major veins beneath. Flowers solitary, terminal; involucrate bracts 2-4 in number, leaf-like; sepals mostly 3, rarely 2 or 4 in number, yellow green, acute or caudate at the apex, the inner one the largest, 2,5-3 cm long, 2-2.5 cm wide; petals 5—9 in number, spreading, pink or pale pink, often with a pale red spot at the base, 3.5—5.5 cm long, 2—3.1 cm wide; filaments pale pink to pink; anthers yellow; disk entirely enveloping carpels at anthesis, red—purple, leathery; carpels 5, densely tomentose; stigmas sessile, red, 1.5-2 mm wide. Follicles ellipsoid, densely brown-yellow tomentose, 2—2.8 cm long. Seeds black, glossy, 6-8 mm long, 5-7 mm in diameter.

Chromosome number: 2n = 10 (diploid)

Mostly in deciduous broad-leaved forests, rarely on sunny grassy slopes, on limestone rocks or cliffs, at altitudes of 1,000—2,200 m. Confined to W Henan (Xixia County) and W Hubei (Baokang County and Shennongjia).

To date, Paeonia qiui has been found in only four localities. Three of the four remaining populations were found on cliffs and comprised only a few individuals. It is surely the most endangered species in Paeonia, on the verge of extinction, and therefore effective measures must be undertaken urgently to conserve the species. Prof LI Zhen-Yu informed me recently that he saw this species with certainty in Zhuxi County of Hubei Province.

Paeonia qiui is characterised by having biternate lower leaves consistently with 9 leaflets, which are ovate-lanceolate to broad-ovate, mostly entire and densely villose at the axils of major veins beneath. It has whitish pink or pink petals, often with a pale red blotch at the base. Apparently, P. qiui is most closely related to P. cathayana and P.jishanensis. It sometimes reproduces vegetatively by turions.

The Peony Society also has a page about this species here.

If you need more info about paeonia species, click here.

Kew Plants of the world lists accepted species and synonyms: here.

Source:
Hong, De-Yuan. “Peonies of the World. Polymorphism and diversity.” Kew: Royal Botanic Gardens, 2011, p. 91-92.

Paeonia ostii


Shrubs up to 1.5 m tall. Stems brown-grey. Lower leaves ternate-pinnate, with 11—15 leaflets; leaflets lanceolate to ovate-lanceolate, mostly entire, terminal leaflets often 2-3-lobed, very occasionally 1-2 lateral leaflets also 2—lobed, rounded at the base, acute to acuminate at the apex, 5—13 cm long, 2.5—6 cm wide, glabrous on both surfaces but sometimes pubescent at the base or the lower part of major veins above. Flowers solitary, terminal, single; involucrate bracts 3—6 in number, green, leaf-like; sepals 4—6 in number, green-yellow, broad-elliptic or ovate-orbicular, 1.5-3.1 cm long, 1.5—2.5 cm wide, shortly caudate or acute at the apex; petals usually 11-14 in number, white, rarely pinkish, obovate, 5.5-8 cm long, 4-6 cm wide, entire or incised at the apex; filaments purple-red; anthers yellow; disk entirely enveloping carpels at anthesis, purple—red, leathery, dentate or lobed at the apex; carpels 5, densely tomentose; stigmas sessile, red. Follicles oblong, densely brown-yellow tomentose. Seeds brown—black, oblong—spherical or spherical, 8—9 mm long, 7-8 mm in diameter.

Chromosome number: 2n=10 (diploid)

In deciduous broad-leaved forests and thickets on slopes at an altitude of 300-1 ,600 m.

Native in Anhui (Chaohu) and W Henan (Lushi County and Xixia County); cultivated in Anhui, Henan, Hubei, Shaanxi, Sichuan, and other provinces. This species is widely but sporadically cultivated in China as a traditional medicine.

The distinctive characters of Paeonia ostii are its ternate-pinnate lower leaves, with the leaflets 11-15 in number and ovate, ovate-lanceolate, mostly entire; flowers single and pure white, rarely pale pink; filaments red-purple; disk dark purple and stigmas red.

Paeonia ostii is considered a distinct species, but had been confused with P. suffruticosa subsp. suffruticosa (Pan, 1979). We have compared P. ostii to plants commonly cultivated for mudanpi (a famous Chinese traditional medicine) in Tongling, Anhui Province, the locality in which mudanpi is famously cultivated. They resemble each other very closely, and thus the plant commonly cultivated for mudanpi should be identified as P. ostii. Paeonia ostii is cultivated on a large scale in Tongling, Anhui Province, and to a lesser extent in other provinces such as Henan, Hubei, Shaanxi and Sichuan.

HONG Tao and his co-workers (Hong et al., 1992) stated that the shrub from which the type was collected was introduced from “Songxian, Yangshan, 1,200 m, in thickets on slopes”. We visited Songxian, Mt Yangshan, in Henan Province twice, in 1994 and 1997, and searched extensively for P. ostii in the mountains. We did find the species cultivated in Secaogou Village, but not in the wild. In 1998, however, we found it in Western Henan in Lushi County (D. Y. Hong et al. H98005).

We here designate a neotype for Paeonia ostii, since the original material cited in the protologue (Hong & Zhang, 1992) was not preserved. The protologue stated that it had been preserved in CAF but the keeper of the herbarium could not find it, and was told by HONG Tao that no holotype specimen had been preserved.

The Peony Society also has a page about this species here.

If you need more info about paeonia species, click here.

Kew Plants of the world lists accepted species and synonyms: here.

Source:
Hong, De-Yuan. “Peonies of the World. Polymorphism and diversity.” Kew: Royal Botanic Gardens, 2011, p. 84-86.

Paeonia rockii


Shrubs to 1.8 m tall. Roots cylindrical, attenuate downwards. Turions absent. Stems grey or grey—brown, peeling off in flakes. Lower leaves ternatepinnate, ternatebipinnate or biternatepinnate, with 17-33 leaflets; leaflts lanceolate to ovatelanceolate and mostly entire, or ovate to ovate-orbicular and mostly lobed, 2—11 cm long, 1.5-4.5 cm wide, glabrous above, villose along veins beneath, truncate to cuneate at the base, acute or acuminate at the apex. Flowers solitary, terminal; involucrate bracts 3—4 in number, leaf—like; sepals 4—7 in number, green, ovate-lanceolate, ovate-orbicular or orbicular, all caudate at the apex, 3—4 cm long, 3—4.5 cm wide; petals 8—13 in number, obovate, entire or irregularly incised, white or rarely red, with a large and dark purple blotch at the base, 5-9 cm long, 4—7 cm wide; filaments yellow; anthers yellow; disk entirely enveloping carpels at anthesis, pale yellow, leathery, dentate or lobed at the apex; carpels 5, rarely 6, densely tomentose; styles 0.5-2 mm long, tomentose; stigmas pale yellow. Follicles oblong, densely yellow tomentose, c. 3 cm long.

Chromosome number: 2n=10 (diploid)

In deciduous broad-leaved forests, forest margins or thickets, on shady slopes of limestone areas, at altitudes from 850 to 2,800 m.

Confined to S Gansu, W Henan, W Hubei, S Ningxia, Shaanxi, and N Sichuan.

This species is characterised by having lower leaves ternate-pinnate, biternate-pinnate or ternatebipinnate; leaflets usually number 19-33, very rarely fewer than 19, the filaments are yellow, with the disk yellowish white and the stigmas yellow, as well as the highly distinctive petals of white, rarely red, with a large dark purple blotch at the base. Thus, this species is clearly distinguished from the remaining four in the Paeonia suffruticosa complex: P. jishanensis, P. ostii, P. qiui and P. cathayana. Its petals are the largest in the whole genus, reaching to 9 x 7 cm in length and width, respectively.

Two allopatric subspecies can be readily recognised by the key couplet below:

1a. Leaflets lanceolate to ovate-lanceolate, all or mostly entire: subsp. rockii

1b. Leaflets ovate to ovate-orbicular, all or mostly lobed: subsp. atava

 

Paeonia rockii subsp atava

Chromosome number: 2n=10

Growing in deciduous forests at an altitude of 1,100—1,750 m.

According to our present knowledge, subsp. atava is confined to E Gansu, S Ningxia and Shaanxi on northern slopes of the Qinling Range and further N.

The subspecies is clearly differentiated from the typical one in having the leaflets ovate or ovate-orbicular, mostly or all lobed. In this subspecies, the petals are usually white with a large, dark purple blotch at the base, but in the Longbagou Mountain, Xiashiwan Township (Ganquan County, Shaanxi Province), we found a population (D. Y. Hong, K. Y. Pan & Y. Ren H06003) in which white-flowered and red- flowered individuals coexisted.

Readers may feel surprised when we state that P. rockii subsp. atava (Brühl) D. Y. Hong is confined to a small area in eastern Gansu, southern Ningxia and Shaanxi, as the type was from Yadong, Xizang (Tibet). Hong (1997) explained this clearly. Paeonia rockii subsp. atava is native to the Qinling Range and further north. It is highly possible that Buddhist monks from Mt Taibai in the Qinling Range cultivated this peony. Many individuals of this striking peony are cultivated in front of the Dadian Lamasery on Mt Tabai and distributed to lamaseries elsewhere.

 

Paeonia rockii subsp rockii

Chromosome number: 2n = 10 (diploid)

Usually growing in deciduous forests, usually in limestone areas at an altitude of 850—2,800 m.

Relatively widely distributed in five provinces: SE Gansu, W Henan, W Hubei, S Shaanxi and N Sichuan.

The Peony Society also has a page about this species here.

If you need more info about paeonia species, click here.

Kew Plants of the world lists accepted species and synonyms: here.

Source:
Hong, De-Yuan. “Peonies of the World. Polymorphism and diversity.” Kew: Royal Botanic Gardens, 2011, p. 78-79.

Shape of the sepals is probably the easiest characteristic. With a tail or a small tip on top in P. cathayana, whilst this is missing in P. jishanensis.

Paeonia cathayana


Shrubs about 0.8 m tall. Leaves glabrous; lower leaves biternate, with 9 leaflets; terminal leaflets obovate—deltoid, 8—10 cm long, 7-9 cm broad, 3- or 5-cleft to the middle or even beyond, lateral leaflets ovate or ovate-lanceolate, 4-7 cm long, 2-4.5 cm broad, entire or shallowly lobed. Flowers solitary, terminal, single; involucrate bracts 2—6 in number, glabrous; sepals 4—5 in number, all caudate at the apex, 3-3.5 cm long, 2-3 cm broad, glabrous; petals 9 or 10 in number, rose, broadly obovate, rounded at the apex, 5-6 cm long, 4-6 cm broad; filaments purple, anthers yellow; disk entirely enveloping carpels at anthesis, purple; stigmas purple.

Chromosome number: 2n=10.

Native to W Henan (Songxian) and W Hubei (Baokang).

When we (Hong et al., 1998) described Paeonia suffruticosa subsp. yinpingmudan as new, we cited two specimens, one from a cliff in the Yinping Hill, Chaohu, Anhui Province (K. Y. Pan & Z.W Xie 9701) and the other from a cultivated shrub next to Mr YANG Hui-Fang’s house in Secaogou Village, Shigunping, Muzhijie Township, Songxian County, Henan Province (D. Y. Hang, Y. Z. Ye & Y. X. Feng H97010). The former has only one leaf and several white petals, whereas the latter, with rose petals, was introduced from a nearby mountain around 1961, as Mr Yang told us. These two specimens were considered to form a single entity, and possibly a wild form of the cultivated tree peony on the basis of similarity of the leaves, although they had different petal colours. It is regretful that we designated 9701, instead ofH97010, as the type of P. suffruticosa subsp. yinpingmudan, considering that the former came from an individual of wild origin with considerable certainty, but ignoring its incompleteness as a specimen.

Our recent DNA sequencing data do not support this taxonomic treatment. On all the molecular trees of the nuclear GPAT gene, the nuclear gene family Adh1A, Adh1B and Adh2, and cpDNA, K. Y. Pan & Z. W. Xie 9701 and P. ostii formed a clade, whereas H97010 either formed an independent clade or formed a clade with P. qiui (Zhao et al., 2004; Lin et al., 2004; Zhou et al., unpub.).

Haw (2006) strongly argued that Paeonia suffruticosa subsp. yinpingmudan from Anhui is an element of P. ostii, but not the direct progenitor of P. suffruticosa. According to his observation, the peony on the cliff from Yinping Hill in Anhui Province has lower leaves with 11 instead of 9 leaflets. Mr LI Min and Mr MA Xin-Tang made a trip to Yinping Hill in April of 2006 to further observe the peony on the cliff. They collected petals falling down the cliff and took a large number of photos using a telelens. According to their photos, the lower leaves of this tree peony actually have 13 (not nine) leaflets, which are ovate-lanceolate or ovate, and mostly entire (Hong & Pan, 2007). The leaf of the type specimen of P. suffruticosa subsp. yinpingmudan (Pan & Xie 9701, with nine leaflets) (Hong et al., 1998) might be a middle leaf but not a lower one. The flowers of this type specimen are purely white, with purple filaments and disc. Therefore, there are no significant differences between the tree peony on the cliff (Pan & Xie 9701) and the specimens of P. ostii that we have examined to date. The tree peony in Songxian of Henan Province (Hang et al. H97010), however, differs from P. suffruticosa subsp. yinpingmudan in having the lower leaves strictly with nine leaflets, mostly lobed, and rose petals. Therefore, the two collections of tree peonies cited when P. suffruticosa subsp. yinpingmudan was described as new actually belong to two different entities, Pan & Xie 9701 (Anhui) being an element of P. ostii as shown by DNA data and as stated by Haw (2006), whereas Hong at al. H97010 (Henan) might be a real wild form of the cultivated tree peony. Thus, Paeonia suffruticosa subsp. yinpingmudan from Anhui is reduced herein to a synonym of P. ostii, whereas the tree peony from Henan has been described as a new species, P. cathayana (Hong & Pan, 2007).

Mr B. A. Shen’s Paeonia yinpingmudan subsp. henanensis (Shen, 2001) is an illegitimate name because D. Y. Hong and his co-workers never gave the Latin name ‘henanensis’, and neither did Mr Shen designate a type for his name ‘henanensis’. However, from Mr Shen’s short note in Chinese, his ‘henanensis’ is clearly connected with Hong, Ye & Feng H97010.

The Peony Society also has a page about this species here.

If you need more info about paeonia species, click here.

Kew Plants of the world lists accepted species and synonyms: here.

Source:
Hong, De-Yuan. “Peonies of the World. Polymorphism and diversity.” Kew: Royal Botanic Gardens, 2011, p. 94-97.

Paeonia jishanensis


Shrubs to 1.8 m tall. Roots attenuate downwards. Turions present. Stems grey or grey—brown. Lower leaves biternate, with 9 leaflets, very occasionally terminal leaflets 3—fid to the base, and thus with 11 or 15 leaflets; leaflets ovate-orbicular or orbicular, 3—cleft, 4-8 cm long, 3-11 cm wide, glabrous above, villose along veins or throughout beneath; segments lobed, segments/lobes acute to rounded at the apex. Flowers solitary and terminal; involucrate bracts 2-4 in number, long-elliptic, unequal in size; sepals 3 or 4 in number, green or yellow-green, broad—ovate, 2.5-5 cm long, 1.8—2.5 cm wide, all rounded at the apex; petals 5-11 in number, white, occasionally pinkish at the base or on margins, obovate, 4.5-7.2 cm long, 4—6 cm wide, irregularly incised at the apex; filaments pink or purple, white above, 8—10 mm long; anthers yellow, linear, 8-10 mm long; disk entirely enveloping carpels at anthesis, red-purple, leathery, dentate at the apex; carpels 5, densely tomentose; stigmas red. Follicles oblong, densely brown-yellow tomentose. Seeds dark brown, nearly spherical, 8-9 mm in diameter.

Chromosome number: 2n=10 (diploid)

In secondary deciduous broad-leaved forests and well-developed thickets at an altitude of 900—1,700 m. Native to N Henan (Jiyuan County), C Shaanxi (Huayin County and Tongchuan City), and SW Shanxi (Jishan and Yongji counties).

According to the protologue, the holotype of Paeonia jishanensis is preserved in CAF. However, when we visited this herbarium and asked HONG Tao for the holotype, we were told that it had not been preserved. Thus, we designate a neotype herein.

Haw (2001) used the specific name Paeonia spontanea (Rehder) T. Hong & W. Z. Zhao (in Hong et al., 1994), while treating P. jishanensis T. Hong & W. Z. Zhao (1992) as its synonym. He cited T. Hong and Zhao’s (1992) statement “P. suffruticosa subsp. spontanea has petaloid stamens, which are an important characteristic developed after domestication of a wild tree peony, so that P. suffruticosa subsp. spontanea should be reduced to the status of a cultivar, ‘spontanea’” (translated by Haw from the original Chinese). After the citation, Haw (2001) noted that “Hong and Zhao included the type of P. suffruticosa subsp. spontanea (i.e. W. Purdon 338) in their concept of the species P.jishanensis”, and concluded that “the name P. jishanensis, typified by Hong Tao 915010, is therefore, superfluous and illegitimate”. We (Hong & Pan, 1999) restored P. jishanensis T. Hong & W. Z. Zhao as a valid specific name. Here, we still argue for its legitimate status. First, although T. Hong and Zhao (1992) did say that P. suffruticosa subsp. spontanea should be reduced as a cultivar, they did not say “in P. jishanensis”. Second, in the same paper, they (T. Hong & Zhao, 1992) stated that “the present species (P. jishanensis) differs from Paeonia suffruticosa Andrews var. spontanea Rehder mainly in having petals white and lacking petaloid stamens.” This statement clearly indicates that P. suffruticosa var. spontanea was not included in the circumscription of P. jishanensis by T. Hong and Zhao (1992). The type of P. jishanensis, Hong Tao 915010, can not be confused with the type of P. suffruticosa var. spontanea, W Purdom 338, as it was selected by Haw (2001). Therefore, P. jishanensis T. Hong & W. Z. Zhao is a legitimate name.

The Paeonia jishanensis group has been treated at three different levels: as the variety P. suffruticosa var. spontanea by Rehder (1920), Stern (1946), Anonymous (1972), and Pan (1979); as the subspecies P. suffruticosa subsp. spontanea by Haw and Lauener (1990); and as an independent species by Hong and Zhao (in Hong et al. 1994). The most distinct morphological character of P. jishanensis is its calyx with three or two sepals, which are all rounded at the apex and rather large, up to 5 cm long. This calyx morphology is unique in sect. Moutan DC. Another distinct feature of this species is vegetative reproduction by turions, and these long scaly shoots produced from underground stem buds can reach over 1 m long. Seeds could scarcely be found. Digging roots of this species for market as danpi, a traditional Chinese medicine, was a serious activity for several years around 1960. The species probably escaped extinction solely because of its reproductive strategy of turions.

Paeonia jishanensis is rarely found in scattered locations in the Zhongtiao Mountains (Yongji County in Shanxi and Jiyuan County in Henan), the Luliang Mountains (Jishan County, Shanxi), the Huashan Mountains (Huayin County, Shaanxi), and Tongchuan and Yan’an (both in Shaanxi). All of these populations, except the one in Yan’an (the type locality of P. suffruticosa var. spontanea Rehder), grow in thickets or secondary deciduous forests at altitudes from 900 to 1,700 m. The population in Yan’an consists of several individuals on the western side of the peony garden behind Zhaojun Temple in Wanhua Shan, and may well be introduced and naturalized there. Because the garden has probably been established for hundreds of years, and no one (including local people) knows its exact history and it is hard to give a definite answer about the history of P. jishanensis in Yan’an. All the populations mentioned above have purely white petals that are occasionally pinkish at the periphery.

The Peony Society also has a page about this species here.

If you need more info about paeonia species, click here.

Kew Plants of the world lists accepted species and synonyms: here.

Source:
Hong, De-Yuan. “Peonies of the World. Polymorphism and diversity.” Kew: Royal Botanic Gardens, 2011, p. 87-91.

The sepals are the green coverings protecting the petals. When they are larger, you have the two species from North America. By far most peony species have petals which are larger than the sepals and thus the first category is the most obvious answer if you're in doubt.

Paeonia brownii


Perennials, glabrous throughout except for leaf margins. Roots all slightly fusiform, up to 2.4 cm in diameter, brown—black outside. Caudex (rhizomes) up to 12 cm long, 0.6—1.3 cm in diameter; stems 15-48 cm tall, up to 1 cm in diameter, with 5-7 scales at the base, usually with no branches but sometimes with fertile or sterile branches. Lower leaves biternate with 9 leaflets, petioles 3—7 cm long; each leaflet with several segments, each segments with several final lobes; segments 0.3-2.0 cm wide; final lobes 59—110 in total, oblong or ovate-lanceolate, rounded or acute, sometimes mucronate at the apex, 0.2—1.2 cm wide, margins thickened and recurved, sometimes with bristles. Flowers terminal, solitary or up to 4 on a stem, pendent; involucrate bracts 1-2 in number, leaf-like; sepals 3-5 in number, green or purple or green but purple at the periphery, more-or-less larger than petals, rounded, 1-2.2 cm long, 1.1-2.1 cm wide; petals 7-10 in number, orbicular, red-brown or brown-purple, often yellow at the periphery, entire, 0.8-1.5 cm long, 0.6-0.9 cm wide, incurved and never fully expanded; stamens numerous; filaments pink, anthers yellow; disk fleshy, dentate, 3 mm high; carpels mostly 5, rarely 4, very occasionally 6, 3 or 2 in number; stigmas sessile, 1.5-1.9 mm long, c. 1 mm wide, purple, horizontal. Follicles cylindrical, 2-4 cm long, 1.2-1.9 cm in diameter. Seeds black, oblong, 10-12 mm long, 6-6.5 mm in diameter.

Chromosome number: 2n=10 (diploid)

Usually growing in sparse chaparral, open places in chaparral or woods of Pinus, Picea or Populus, or on grassy slopes. The plants with which it is most frequently associated are Pinus ponderosa, Pseudotsuga menziesii, Calocedrus decurrens, Populus tremuloides, Larix sp., Castanopsis sp., Ceanotus sp. and Artemisia spp. The species mostly occurs in granite soils or on volcanic rocks at altitudes from 600 to 2,600 m. Confined to the USA and distributed in N California, Idaho, Nevada, Oregon, Utah, Washington and Wyoming.


Of the two species in sect. Onaepia, Paeonia brownii is distinct with lower leaves having 9 leaflets, carpels mostly 5, less frequently 4 in number, and petals always smaller than sepals. The two species are allopatric.


A good image of the species can be found here.

The Peony Society also has a page about this species here.

If you need more info about paeonia species, click here.

Source:
Hong, De-Yuan. “Peonies of the World. Taxonomy and phytogeography.” Kew: Royal Botanic Gardens, 2010, pp. 97-98.

Paeonia californica


Perennials totally glabrous. Roots slightly fusiform—thickened, up to 3 cm in diameter. Caudex (rhizomes) up to 8 cm long. Stems 40-70 cm tall, entirely green, up to 1.2 cm in diameter, usually with sterile or fertile branches. Lower leaves ternate, very occasionally nearly biternate; petioles 4-13 cm long; leaflets 3 in number, each leaflet with three or several segments, each segment with two or several lobes, rarely entire, segments and/or lobes totalling 33-78 in number; segments 3-8 cm long, 0.4-2.0 cm wide; lobes linear to lanceolate, usually acute, sometimes mucronate at the apex, 0.2-3.0 cm long, 0.2-1.2 cm wide. Flowers terminal, solitary but usually several, up to 6 in number on a stem, pendent; involucrate bracts usually 1 or 2 in number, leaf-like; sepals 3 or 4 in number, rounded, green or green but purple at the periphery, or purple, 1.2-2.0 cm long, 1.2-2.0 cm wide, as large as or slightly smaller than petals; petals 6-8 in number, entire, purple, dull dark red, dark purple red or brownish purple, 1.2-2.2 cm long, 1.0-2.0 cm wide: stamens numerous; filaments yellow; anthers yellow; disk fleshy, yellow, dentate, teeth variable in shape, 2.5-6 mm high; carpels 3, less frequently 2, occasionally 4, 5 or 6 in number, glabrous; stigmas sessile, 3 mm long, 2 min wide, horizontal. Follicles cylindrical, 2.5-4.2 cm long, 1.1-1.7 cm in diameter. Seeds oblong, black, 10-12 mm long, 5.5-6 mm in diameter.


Chromosome number: 2n = 10 (diploid).


Growing from coastal areas with altitudes of only 30 m to mountain areas with altitudes up to 1,200 m at Corte Madera Ranch, San Diego County. It occurs mostly in chaparral, or openings, or on edges of chaparral and Quercus Woods, with Adenostemma fasciculata, Erodictyon crassifolium, Eriogonum fasciculata, Rhus laurina, Salvia mellifera and Artemisia californica most frequently found as associated plants. It prefers dry granite soils. Confined to the northern-most Baja California of Mexico and to S California, USA.


Paeonia californica is recognised as an independent species by most taxonomists. However, Brewer and Watson (1876), Jepson (1909, 1923) and Munz (1935) treated it as synonymous with P. brownii Douglas ex Hook., Whereas Lynch (1890) reduced it to a variety of P. brownii. Stebbins (1938) clearly documented the distinctness of P. californica from P. brownii, but Halda (1997, 2004) still recognised the former as a subspecies within the latter. We made field observations and carried out population sampling in 2005 in southern California with the assistance of Dr J. Z. Qiu, and in the Blue Mountains guided by Paige Woodward from Canada. We sampled two populations in California and three in Oregon. In addition, we conducted field observation on P. brownii in 1999 in Idaho, guided by Dr jenny Q. Y. Xiao. According to our observations and population samples, the lower leaves of P. californica are always ternate, a unique aspect in the genus, whereas they are always biternate in P. brownii. The carpels number mostly three (27/34, i.e. 80%), less frequently two, occasionally four, five or six in P. californica, but mostly five (29/39, i.e. 74.4%), rarely four, very occasionally six or three in P. brownii. The number of final lobes on the lower leaves ranges from 33 to 78 in P. californica and 59—110 in P. brownii, and these two ranges are statistically discontinuous. Our cluster analysis (the unweighted pair-groups method using arithmetic averages, i.e. UPGMA) shows that these two entities are morphologically distinct and should be better treated as two separate species.


A good image of the species can be found here.


The Peony Society also has a page about this species here.


If you need more info about paeonia species, click here.


Hong, De-Yuan. “Peonies of the World. Taxonomy and phytogeography.” Kew: Royal Botanic Gardens, 2010, pp. 103-105.'

The section albiflorae is characterised by the fact that sepals are caudate, meaning that they have an elongated part at the top, a 'tail'. If your plant has such sepals, it falls in this group. P. anomala and P. sterniana, the only two species within this section with solitary flowers, are also characterised by the fact that these flowers are (slightly) nodding at bloom time, and are thus not perfectly upright on the stems.

The leaf in P. lactiflora has thickenings at the edge, which are uneven. Besides that P. lactiflora has upfacing flowers, whilst all others have somewhat sideways facing flowers.

Paeonia lactiflora


Herbs perennial. Roots thick, cylindrical or carrot—shaped, attenuate toward tip, up to 30 cm long, 2 cm in diameter. Stems up to 1 m tall, glabrous, very occasionally hispid. Lower leaves biternate; terminal leaflets often 2- or 3—segmented; leaflets/leaf segments 10-15, rarely 9 in number, lanceolate or ovate-lanceolate, cuneate or decurrent at the base, acute at the apex, 4.5—16 cm long, 1.5—6 cm wide, usually with bristles along veins or sometimes glabrous above, glabrous or sparsely pubescent along veins beneath; margins white cartilaginous-thickened, dentate—spinose on the thickenings. Flowers usually 3—4 on a stem, both terminal and axillary, sometimes only the terminal one developed with 2—3 axillary sterile buds, very rarely solitary without sterile flower buds, single (in wild populations) or double (in cultivated plants), 8—13 cm across; involucrate bracts 4 or 5 in number, unequal, leaf-like; sepals 3 or 4 in number, broadly ovate or suborbicular, 1—2 cm long, 1-1.7 cm wide, all caudate at the apex; petals 9-13 in number, white or pink (in wild populations), or various in colour (among cultivated plants), obovate, 3.5—6 cm long, 1.5—4.5 cm wide; filaments yellow; anthers yellow; disk yellow or red, 1—5 mm high, waved or incised; carpels 2-5 in number, green, red or purple, glabrous or rarely sparsely hispid or tomentose, with hairs 1-1.5 mm long; stigmas sessile, red, 1.5—2.5 mm wide. Follicles ovoid or oblong-ellipsoidal, 2.5-3 cm long, 1.2-1.5 cm in diameter. Seeds black, ovoid- spherical, 7 mm long, 6 mm in diameter.


Chromosome number: 2n=10


Growing in bushes and grasslands, but also in open woods, at altitudes from lowlands to 2,300 m, but to 3,400 m in Sichuan Province (Kangding), China. In E Asia: China, the Korea Peninsula, E Mongolia, and Russia (the Far East and SE Siberia).


The most distinct character of Paeonia lactiflora is the cartilaginous thickening along the leaf margins, which are dentate—spinose on these thickenings. Historically, the crossing experiment conducted by Saunders and Stebbins (1938) demonstrated that this species was incompatible with P. anomala, P. Veitchii, P. emodi, and four other species, and thus seemed in a very isolated position. However, our unpublished molecular data (CPAT, Adh1 and Adh2) imply that the species is closely related to P. emodi. In the subsection Albiflorae, P. emodi and P. lactiflora have fewer leaflets/ leaf segments.


Petals and carpels in Paeonia lactiflora are rather variable in colour in wild populations. The former were found varying from pure white, whitish pink to pink, whereas the latter varied from green, pink, red, purple to dark purple even within a single population. We found both glabrous and pubescent carpels within populations, and therefore P. albiflora var. trichocarpa Bunge is here treated as synonymous to P. lactiflora.


This species is widely cultivated for both ornamental and medicinal purposes. Flowers are most often doubled in cultivated varieties of Paeonia lactiflora.


The Peony Society also has a page about this species: here.


If you need more info about paeonia species: here.


This species overview and synonyms on Kew Plants of the World Online: here

Source: Hong, De-Yuan. “Peonies of the World. Taxonomy and phytogeography.” Kew: Royal Botanic Gardens, 2010, pp. 111.'

Paeonia anomala


Perennials. Tap roots up to 1 m long, thickened, carrot—shaped, attenuate downwards, up to 2 cm in diameter, lateral roots also carrot-shaped, neither tuberous nor fusiform. Lower leaves biternate; leaflets often decurrent, finely segmented; lower leaves with leaflets 9 and segments 70—100 in number; segments 2—13 cm long, 0.8—3.2 cm wide, with bristles along veins above, glabrous beneath. Flowers solitary or 2-4 on a stem, often only the terminal one fully developed and blooming; involucrate bracts 1—3 in number, leaf—like; sepals 3-5 in number, mostly caudate at the apex, rarely 1 or very occasionally 2 non—caudate, hispidulous only near the top on the adaxial surface, glabrous, very rarely hispidulous on the abaxial surface; petals rose, pale red or red, but rarely white in subsp. veitchii, 6—9 in number, obovate, entire or incised at the apex, 4—5.5 cm long, 3-4 cm wide; disk waved, c. 1.5 min high; carpels mostly 3 to 5 in number, densely tomentose, rarely sparsely hairy or glabrous; ovules 12—16 in number per carpel; styles absent or less than 0.5 mm long; stigmas red, 2 mm wide. Follicles columnar, 1.5-2.8 cm long, 1—1.2 cm wide. Seeds ovoid or ovoid-spherical, black, 6—7 mm long, 4.5-5 mm wide.


Chromosome number: 2n = 10 (see the subspecies for detail).


Preferring relatively moist habitats, growing in forests, on the edges of forests, or rarely in bushes or meadows. It is found from lowlands to an altitude of 3,870 m. A few collections recorded limestones, granites and sandstones as the media in which this species grows. Widely distributed from China to the Kola Peninsula of Russia via Siberia and Central Asia.


Pallas’s (1788) illustration has only one name, Paeonia sibirica, and apparently he used this illustration also for P. laciniata, because one sees “Paeonia laciniata” on p. 93. Paeonia laciniata was described in detail by Pallas, but no description was given for P. sibirica by him.


Paeonia anomala had been confused with P. intermedia and P. hybrida long before the work of Hong and Pan (2004), who reviewed the taxonomy of this complex and discussed its relationships in detail on the basis of field observations and examination of the types of these three taxa and a large quantity of specimens. Since the work of Sims (1815), all authors described the root of P. anomala as tuberous (or fusiform), e.g. Anderson (1818), Schipczinsky (1937), Gamaulova (1961), or gave no description of its roots, e.g. de Candolle (1818), Lynch (1890) and Stern (1946). Actually, P. hybrida is a synonym of P. tenuifolia, as in Anderson’s treatment (1818). According to our observations in the Altai, the populations that had the majority of sepals caudate at the apex always had carrot—shaped roots, whereas those with more sepals rounded (non-caudate) at the apex always had tuberous roots. The examination of specimens from Siberia and Mongolia shows that they consistently had the majority of sepals caudate at the apex and carrot-shaped roots. The type of P. anomala L. is from Siberia, and the two sepals visible on the sheet are both caudate at the apex. Most specimens examined from western and southern parts of the Altai westward to Uzbekistan had tuberous roots, if roots were collected, and most sepals were non-caudate. The type of P. intermedia C. A. Mey., which was collected from the Altai, has tuberous roots. It is clear that P. anomala has carrot-shaped roots, which are correlated with caudate sepals, whereas P. intermedia has tuberous roots, which are correlated with non-caudate sepals.


Saunders and Stebbins (1938) made crosses between P. anomala and P. veitchii, P. anomala and P. beresowskii, P. anomala and P. woodwardii, P. veitchii and P. beresowskii, P. veitchii and P. woodwardii, and P. beresowskii and P. woodwardii. All of these species pairs were easily crossed and the hybrids were fertile, similar to crosses between individuals of the same subspecies. This is consistent with the conclusion we reached on the basis of external morphology: these four taxa fall within the same species.


Paeonia anomala has two allopatric subspecies, with the typical subspecies distributed northwest of the Gobi, whereas the subspecies veitchii is in China southeast of the Gobi.


 

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This species overview and synonyms on Kew Plants of the World Online: here

Hong, De-Yuan. “Peonies of the World. Taxonomy and phytogeography.” Kew: Royal Botanic Gardens, 2010, pp. 125-127.'

Paeonia veitchii


Herbs perennial. Tap roots up to 60 cm long, thickened, carrot-shaped, attenuate downwards, up to 2 cm in diameter, lateral roots, if present, also carrot-shaped, neither tuberous, nor fusiform. Stems single or 2 -3-caespitose, simple, mostly 25 – 59 cm, rarely up to 70 cm tall. Lower leaves biternate, with leaflets 9 and segments 70 – 100 in number; leaflets often decurrent, finely segmented; segments 1.5 – 10 cm long, 0.3 – 2 cm wide, with bristles along veins above, glabrous beneath. Flowers usually 2 – 4 on a stem, forming a cyme, less frequently solitary but with one or two undeveloped flower buds, rarely simply solitary; involucrate bracts 1 – 3 in number, leaf-like; sepals 3 – 5 in number, mostly caudate at apex, rarely one or occasionally two non-caudate, glabrous, very rarely hispidulous on abaxial surface; petals rose, pale red, red, less frequently white, 6 – 9 in number, obovate, entire or incised at apex, 4 – 5 cm long, 3 – 4 cm wide; disk waved, ca. 1.5 mm high; carpels mostly 3 or 2, rarely 4 or 1 in number, densely tomentose, rarely sparsely hairy or glabrous; ovules 12 – 16 in number per carpel; styles absent or less than 0.5 mm long; stigmas red, 2 mm wide. Follicles columnar, 1.5 – 3 cm long, 1 – 1.5 cm wide. Seeds ovoid or ovoid-spherical, black 6 – 7 mm long, 4 – 5 mm wide.

Phenology. Flowering from late April to early June; fruiting in August and September.

Chromosome number. 2n=10 (diploid)

Habitats and distribution. Relatively moist places : forests, edges of forests, rarely in bushes or meadows; from 1,800 to 3,870 m alt. A few collections recorded from the localities with limestones, granites and sandstones as the medium. Widely distributed in China: SE & C Gansu, E. Qinghai, S Ningxia, Shaanxi (Qinling Range), Shanxi, W Sichuan, Tibet (Eastern extreme) and NE Yunnan.

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This species overview and synonyms on Kew Plants of the World Online: here

Source: Hong, De-Yuan. “Peonies of the world. Part III: Phylogeny and evolution.” Kew Publishing: Royal Botanic Gardens, Kew, 2021, pp. 227-228

Paeonia emodi


Perennials. Roots carrot-shaped, up to 2.5 cm in diameter. Caudex short, not elongated. Scales at the base of stems 5—8 in number, purple—red. Stems up to 60 cm tall, green. Lower leaves biternate, with some or all of 9 leaflets segmented; leaflets/leaf segments 15—27 in number, ovate-lanceolate to lanceolate, 7—14 cm long, 1.5—3.8 cm broad, glabrous or with sparse bristles along veins above, always glabrous beneath, some segments lobed, lobes acuminate at the apex. Flowers mostly 2—3, terminal and axillary at axils of the upper leaves, rarely solitary and terminal; involucrate bracts 3-4 in number, leaf-like; sepals 3-4 in number, green, ovate-orbicular to orbicular, all caudate at the apex, 1.2-2.0 cm long (tailed part excluded), 1-2 cm broad; petals white, 8—10 in number, obovate, often bilobate, c. 4 cm long, c. 3 cm broad; filaments yellow; anthers yellow; disk pale pink, waved; carpels single, occasionally 2, green, tomentose with hairs 1—2 mm long, less frequently glabrous; styles absent or up to 1 mm long; stigmas pink, 1 min wide. Follicles long—ovoid or ellipsoid, 2-3.5 cm long, 1.2—1.5 cm in diameter. Seeds brown—black, oblong, 7-9 mm long, 3.5-6 mm in diameter.

Chromosome number: Diploid with 2n = 10 and tetraploid with 2n=20 (in Xizang (Tibet))

Growing in bushes on dry or rocky slopes at altitudes from 1600 to 3,200 m. The western Himalayas and northeastern part of the Hindu Kush: China (SW Xizang (Tibet) and S Xinjiang), NW India, W Nepal, N Pakistan and E Afghanistan (Nuristan, Chetras) .

Hooker & Thomson (1875) described a form of Paeonia emodi with glabrous carpels as the variety glabrata. All six flower specimens that I examined in the Herbarium of Royal Botanic Garden Edinburgh (E) have tomentose carpels and follicles. However, in other collections at the Conservatoire et jardin botaniques de la Ville de Geneve (G), the carpels and follicles of seven flowers (from five specimens) are tomentose; whereas those of four flowers are glabrous. Falconer 77 from Kashmir (P) has two individuals (stems) that are alike; their carpels are both single, but one is glabrous whereas the other is tomentose. According to Miss J. Coote’s field observation in Kashmir, the form with tomentose carpels and that with glabrous carpels “grew together and they were exactly alike in height, appearance and mode of growth”. It seems to us that pubescent or glabrous carpels reflect another example of polymorphism in carpel character for Paeonia emodi.

Paeonia emodi most resembles P. anomala, P. sterniana and P. lactiflora, but it differs from all of these species in having the carpels mostly single (92.6%), rarely two (7.4%). In addition, it is different from P. lactiflora in having leaf margin smooth (rather than cartilaginous thickened and dentate-spinose) and the carpels mostly tomentose (88%; rather than usually glabrous). Paeonia emodi differs from P. anomala in having the leaflets/leaf segments no more than 30 in number (as opposed to 70 to 100), and from P. sterniana in having nearly always multiple flowers per stem (rather than nearly always solitary) and the carpels mostly tomentose (rather than always glabrous).

Saunders and Stebbins (1938) crossed Paeonia anomala and P. emodi, obtaining a very low seed set and sterile hybrids. This supported their observation that the two species are not only morphologically distinct but also reproductively isolated.

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This species overview and synonyms on Kew Plants of the World Online: here

Source: Hong, De-Yuan. “Peonies of the World. Taxonomy and phytogeography.” Kew: Royal Botanic Gardens, 2010, p. 118-120

Paeonia sterniana


Perennials, 35-60 cm tall, glabrous throughout. Roots carrot—shaped, tap roots up to 2 cm in diameter, more than 30 cm long. Caudex short, not elongated, multi—branched, and thus many stems caespitose. Scales at the base of stems 6-9 in number, pink. Lower leaves biternate; leaflets 9, the terminal three often more-or-less decurrent; all leaflets segmented; leaflets/leaf segments 20-30 in number, 4-12 cm long, 1.5-3 cm wide, often lobed; lobes acuminate at the apex. Flowers solitary, terminal, but one or two axillary undeveloped (sterile) buds often present, rarely 2 on a stem; involucrate bracts 2-4 in number, leaf—like; sepals mostly 3, rarely 4 in number, nearly rounded, all or mostly caudate at the apex, green or purple, 1-2.3 cm long, 0.8-2 cm wide; petals white to pale rose, obovate, 2.5-3 cm long. 1.5-2 cm wide; filaments yellow; anthers yellow; disk less than 1 mm high, waved, green—yellow; carpels mostly 2, less frequently 3, rarely 4 in number, green; styles less than 1 mm long, stigmas red, 1.2 mm wide. Follicles ovoid, c. 3 cm long. Seeds ovoidoblong, black, lucid, 7-8 mm long, 5 mm in diameter.

Chromosome number: 2n = 10 (diploid).

Growing in forests or thickets at a high altitude of 2,830—3,500 m. Confined to SE Xizang (Tibet), China.

Paeonia sterniana is closely related to P. emodi. They share a number of characters: the roots carrot-shaped; sepals all or mostly caudate at the apex; leaflets mostly or all segmented; petals white; and plants entirely glabrous except for the carpels, which are mostly pubescent in P. emodi but glabrous in P. sterniana. Nevertheless, these two species distinctly differ from each other. Paeonia emodi often has two or three flowers on a stem, whereas P. sterniana nearly always has a single flower (occasionally two) and sometimes one or two axillary sterile buds on a stem. The carpels are single (93%), rarely two (7%) per flower, and nearly always tomentose in P. emodi, whereas there are two to four, always glabrous carpels in P. sterniana. Therefore, Halda’s (2004) treatment of P. sterniana as a subspecies in P. emodi cannot be justified.

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This species overview and synonyms on Kew Plants of the World Online: here

Source: Hong, De-Yuan. “Peonies of the World. Taxonomy and phytogeography.” Kew: Royal Botanic Gardens, 2010, pp. 122-124

The root shape is the main characteristic, with them being either carrot shaped (gradually becoming smaller from the crown onwards) or fusiform (the roots are attached to the crown first by a thinner part). It's a very easy characteristic, but of course only visible if you dig the plant. If you don't know the root shape, then have a look at the other characteristics, the second most defining one is the number of leaflets/leaf segments. Count the leaflets or leaf segments (if they are 'toothed' you have several segments) on the lowest (and thus largest) leaf which is attached to the stem.

Paeonia officinalis and P. arietina are very close to one another. Especially the easternmost (Eastern part of Turkey) plants of P. arietina, which have more leaflets being also less wide are very alike. The only visible difference there would be the indumentum on the sepals, which is more pronounced in P. arietina.

Paeonia officinalis


Perennials. Roots tuberous-thickened. Caudex short, less than 10 cm long. Stems mostly hirsute, green or purple—red, 25—80 cm tall. Lower leaves biternate, with 9 leaflets; petioles 6-12 cm long, mostly hirsute; petiolules 1-6 cm long, mostly hirsute; leaflets usually segmented; leaflets/leaf segments 11-130 in number, linear-elliptic to elliptic, or oblanceolate, cuneate at the base, acuminate or acute at the apex, lobed or entire, 3—12 cm long, 1-4.5 cm wide, glabrous above, villose, rarely glabrous beneath. Flowers solitary, terminal; involucrate bracts 1—2 in number, leaf-like, relatively distinct from sepals; sepals 3—5 in number, deltoid-orbicular to orbicular, 1-2.5 cm long, 0.8-2 cm wide, mostly rounded at the apex, hispidulous or glabrous on the abaxial side; petals 5—8 in number, pale violet-red or purple-red; filaments purple; anthers yellow; disk up to 1 mm high, flat or waved, red; carpels 1—5, mostly 2—3, in number, tomentose or glabrous, hairs 1.5-2 mm long, yellow, brown or pink; stigmas sessile, red, c. 1.5 mm wide. Follicles long—ovoid when young.

Chromosome number: 2n = 20 (see each subspecies for additional information).

Widely distributed from the Iberian Peninsula to the Balkans via France, Italy and Switzerland.

Paeonia officinalis is the typical species of the genus Paeonia, but its circumscription was not clear and it was confused both with P. peregrina (de Candolle, 1818, 1824; Baker, 1884; Lynch, 1890; Huth, 1891), until the work of Stapf (1918), and with P. mascula (e.g. Fiori, 1898). The species is extremely variable because of great variation in natural populations and extensive cultivation, as demonstrated by the more than 20 specific and many infraspecific synonyms included here. For example, the entity in the Iberian Peninsula and SW France has leaflets/leaf segments numbering more than 50, which are mostly lobed, whereas that in the Balkans has no more than 24 leaflets/leaf segments, which are mostly entire. In the Iberian Peninsula and SW France, the great majority of carpels are glabrous (over 90%), whereas they are totally tomentose in all the other populations. However, the peony here circumscripted cannot be clearly split, and all the differences, even the clear ones mentioned above, are bridged by intermediate forms. Paeonia officinalis is morphologically polytypical with its types closely correlated with geography.

Five types could be recognised and are treated here as five subspecies.

1a. Carpels glabrous, occasionally sparsely hirsute; sepals mostly glabrous; leaflets/leaf segments usually obtuse at the apex, often lobed; stems mostly glabrous: subsp. microcarpa

1b. Carpels tomentose; sepals usually pubescent; leaflets/leaf segments usually acuminate at apex, entire, rarely lobed; stems hirsute or glabrous.

2a. Leaflets/leaf segments 11—24 in number, 2—4.5 cm wide, glabrous or sparsely villose beneath; sepals glabrous or sparsely pubescent: subsp. banatica

2b. Leaflets/leaf segments 19—130 in number, 1—3 cm wide, always villose beneath; sepals always pubescent.

3a. Leaflets/leaf segments 35-130 in number, always with some lobed, 1—2 cm wide: subsp. huthii

3b. Leaflets/leaf segments 19-45 in number, all entire or occasionally very few lobed, 1-3 cm wide.

4a. Leaves villose-floccose beneath, hairs flattened at base: subsp. italica

4b. Leaves hairy but never villose-floccose beneath, hairs cylindrical: subsp. officinalis

Paeonia officinalis subsp microcarpa

Chromosome number: 2n = 20 (tetraploid)

Growing in pine woods or in thickets in limestone areas at altitudes from 400 to 2,050 m. Distributed in Portugal, Spain and SW France.

Paeonia officinalis subsp. microcarpa is rather distinct from the other four subspecies of P. officinalis in having carpels glabrous, or very rarely hirsute. Among 89 flowers examined, only 6 have carpels that are sparsely hirsute and one has moderately hirsute carpels; by contrast carpels in the other four subspecies are all tomentose. Sepals are usually glabrous or sparsely hairy in this subspecies, also contrasting with the others. In addition, the leaflets/leaf segments in this subspecies are generally more numerous than those in the other four subspecies and are often lobed. Seeds ellipsoid, black, 7-8 mm long, 5-6 mm wide.

Paeonia officinalis subsp banatica

Chromosome number: 2n = 20

In thickets or sparse woods of sand soil at altitudes below 1,000 m. Bosnia-Herzegovina, Hungary (S), Romania (SW), and Serbia.

Paeonia officinalis subsp. banatica is rather distinct from the typical one. It has fewer leaflets/leaf segments, mostly 13-18, rarely down to 11 and up to 24, compared to subsp. officinalis with mostly more than 25. The leaflets/leaf segments in this subspecies are wider than those in the other subspecies (2—4.5 rather than 1—3 cm); they are also less densely villose or even glabrous beneath. Sepals are hispidulous or glabrous in this subspecies, Whereas they are always pubescent in subsp. officinalis, subsp. italica, and subsp. huthii.

Seeds ellipsoid, black, 7—8 mm long, c. 5 mm in diameter.

The roots in this subspecies are always tuberous, and sometimes tandom-tuberous, rather long, running horizontally and vertically. Therefore, Rochel’s (1828) figure of the root is wrong, whereas Reichenbach’s (1840) figure of the root is correct. New shoots were found rising from tubers in our field observation at Deliblat in the Banat Region of Serbia in 2003, and thus this subspecies may be vegetatively reproductive to some extent.

Paeonia officinalis subsp huthii

Chromosome number: 2n = 20 (tetraploid)

Growing in sparse Quercus, Fagus or Quercus—Fagus forests or in pastures with sparse Pinus sylvestris trees, in limestone areas, at altitudes from 900 to 1,970 m. A relatively narrowly distributed entity found in NW Italy (Imperia Prov.), and SE and S France. In S France (Herault and le Vigan) the entity meets subsp. microcarpa.

Paeonia officinalis subsp italica

Chromosome number: 2n=20 (tetraploid).

Growing in open communities at an altitude of 650—1,800 m. Confined to central Italy, Croatia and N Albania.

Paeonia officinalis subsp officinalis

Chromosome number: 2n = 20

In sparse pine or oak woods, thickets, or mountain meadows in limestone areas at an altitude of 500—2,000 m. Croatia, N Italy, Slovenia and S Switzerland; relatively common in N Italy.

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This species overview and synonyms on Kew Plants of the World Online: here

Source: Hong, De-Yuan. “Peonies of the World. Taxonomy and phytogeography.” Kew: Royal Botanic Gardens, 2010, p. 230

The differences are very small and mostly related to the colour of the petals. White to pale pink for Paeonia arietina ssp arasicola (not yet officially acknowledged). Pink to red for P. arietina (ssp arietina). And dark red for P. parnassica.

Paeonia arietina


Perennials. Tap roots columnar, lateral roots always tuberous, sometimes tubers beaded. Stems 30-70 cm tall, green, usually entirely hirsute, rarely hirsute only above, with 4-7, rarely up to 15, yellowish green or purplish scales at the base. Lower leaves biternate; leaflets decurrent, usually with some segmented or shallowly dividid; leaflets/leaf segments most frequently 13-23, rarely down to 11 and up to 32 in number; petioles and petiolules densely hirsute; blades elliptic, oblong or ovatelanceolate, cuneate at the base, acute at the apex. 5-12 cm long, 3-6 cm wide, glabrous or villose along major veins above, but mostly densely, very rarely sparsely villose beneath. Flowers solitary and terminal; involucrate bracts 1-3 in number, leaf-like; sepals 3—5 in number, unequal in size, all rounded at the apex, villose outside, green but purple at the periphery; petals 6-9d in number, rose or red, obovate, entire or rarely deeply lobed; filaments purple, anthers yellow; disk waved, glabrous but sometimes hirsute; carpels 2 or 3, less frequently 4 or 5, occasionally 1 in number, yellow tomentose, hairs 2.5 mm long; styles very short or absent; stigmas red, c. 1 mm wide. Follicles 2-3 cm long.

Copyright: Ömer Faruk Gülşen –
Paeonia arietina in Turkey, MUŞ.

Chromosome number: 2n=20 (tetraploid)

Growing usually in sparse oak or coniferous Woods, or in clearings of forests, also in pastures, on limestones but also granites, with a wide range of altitudes from 300 m in Emilia of Italy to 2,100 m in Kutahya Province of Turkey. Distributed in Turkey, Romania, Bosnia-Herzegovina, Albania, Croatia and Italy (Emilia) from the east to the west.

Although Sabine’s taxon has epithet “cretica”, his plant was not from Crete. Stern provides a clear explanation.

The taxonomic treatment of Paeonia arietina G. Anderson (= P. mascula subsp. arietina (G. Anderson) Cullen & Heywood) has been controversial. Paeonia arietina was described first by Anderson, who clearly indicated that his new species was characterised by tuberous roots, pilose stems and petioles, leaflets that are decurrent and glaucous-pilose beneath, and sepals that are pilose at the base. Two varieties were recognised by Anderson in this species: var. andersonii and var. oxoniensis. He described the first from a garden in England and presumed it to be a native of the Levant (near Istanbul, Turkey), and the second from the Oxford Botanic Garden, wrongly considering it a native of Crete following Mr Clusius. De Candolle recognised P. arietina and considered it to be from “Oriente”. Lynch completely followed Anderson, enumerating the two varieties and considering them originally from the Levant and Crete, respectively.
Stern not only recognised Paeonia arietina but also was the first author to indicate its distribution by quoting herbarium specimens. The specimens cited by Stern mostly match Anderson’s protologue very well, e.g. those from Turkey (Anatolia and Amienia), Bosnia and Italy (Emilia).

Cullen and Heywood reduced Paeonia arietina G. Anderson to P. mascula subsp. arietina (G. Anderson) Cullen & Heywood. They ignored Stern’s article, and thus continued to include Crete in the distribution range of this entity. Their treatment was followed by Davis and Cullen, Akeroyd, and Halda. Which treatment is natural? That is to say, is P. arietina an independent species or just a subspecies within P. mascula? In the molecular phylogenies of Paeonia sect. Paeonia produced by Sang and his co-workers, P. arietina, P. parnassica and P. officinalis (including P. humilis = P. officinalis subsp. microcarpa) could not be distinguished from each other on the matK and psbA-trnH trees. Nevertheless, these three species are differentiated clearly from P. mascula subsp. mascula and P. mascula subsp. hellenica on all of these trees. On the basis of ITS sequences for sect. Paeonia, P. arietina, P. parnassica and P. officinalis (including P. humilis) form a group, within which they are indistinguishable from each other, whereas P. mascula subsp. mascula and subsp. hellenica form another group with P. coriacea, P. broteri, P. clusii (including P. rhodia), P. mlokosewitschii (= P. daurica subsp. mlokosewitschii) etc.. The phylogeny of sect. Paeonia reconstructed from a synthesis of the ITS and matK phylogenies indicates that P. arietina, P. parnassica and P. officinalis (including P. humilis) form a group, which is divergent from another group comprising P. mascula (including two subspecies, subsp. mascula and subsp. hellenica, P. coriacea, P. clusii (including P. rhodia) and P. mlokosewitschii. Therefore, molecular phylogeny shows that the P. arietinaP. parnassica group is more closely related to P. officinalis than to P. mascula. Our Adhl and Adhz gene trees also demonstrate that the P. arietinaP. parnassica group form a clade that is separated from the P. mascula clade.

According to our observations, there are distinct differences between the Paeonia mascula group on one side and the P. arietinaP. parnassica group together with the P. officinalis group on the other. In the P. mascula group, the roots are always carrot-shaped, whereas they are tuberous, sometimes even tandem-tuberous, in all populations observed in the P. arietinaP. parnassica and P. officinalis groups. Root shape, whether tuberous or carrot-shaped, has been ignored by nearly all previous authors working on the genus Paeonia, but is a very stable character and thus of great significance in taxonomy. All the individuals observed in the P. arietinaP. parnassica group have hirsute stems, petioles and sepals, whereas these parts are always glabrous in the P. mascula group. These two groups also differ in the indumentum on the lower surface of leaves. Leaves are mostly glabrous, less frequently sparsely hispid beneath in the P. mascula group, but mostly rather densely, very rarely sparsely, villose beneath in the P. arietinaP. parnassica and P. officinalis groups. There are further differences in the shape and size of leaflets/leaf segments. Those in the P. mascula group are obovate, broad-ovate or broad-elliptic, 6-15 cm long, 4-9 cm wide, whereas those in the other two groups are elliptic, ovate-lanceolate or oblong, 5-12 cm long, 1.5—6 cm wide. Therefore, the closest relative of P. arietinaP. parnassica is the P. officinalis group, not P. mascula as in the treatments of Cullen and Heywood, Akeroyd, Davis and Cullen, and Halda.

Paeonia arietina, P. parnassica, P. officinalis and P. banatica are similar to each other in morphology. They share a number of characters: roots tuberous, leaflets mostly segmented, stems, petioles, lower leaf surfaces and sepals nearly always hairy, and chromosome number 2n = 20 (tetraploid). According to our observations, P. arietina and P. parnassica are more similar to each other than to the P. officinalis — P. banatica group. Generally in the P. arietinaP. parnassica group, stems and petioles are always rather densely hirsute, and leaflets/leaf segments are oblong, ovate-lanceolate, or rarely elliptic. By contrast, in the P. officinalis—P. banatica group, stems and petioles are sparsely hirsute or glabrous, and leaflets/leaf segments are ovate-lanceolate, elliptic or linear-elliptic. The most distinct difference between these two groups is perhaps in the indumentum on the abaxial side of the sepals, which is densely villose in the P. arietinaP. parnassica group but densely to sparsely hispidulous or even glabrous in the other group. Within the P. arietinaP. parnassica group, P. arietina has a greater number of leaflets or segments, rose to red petals, and yellow anthers, whereas P. parnassica has dark purple petals and purple anthers.

Remark from the editor: In Turkey, Bursa province, a white flowered variant of this species exists, as yet not well described nor published: Paeona arietina ssp arasicola. We have decided to describe this variant as a subspecies of Paeonia arietina due to the different petal color and geographic distance. Hence the original Paeonia arietina described by Hong also becomes a subspecies Paeonia arietina ssp arietina.

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This species overview and synonyms on Kew Plants of the World Online: here

Source: Hong, De-Yuan. “Peonies of the World. Taxonomy and phytogeography.” Kew: Royal Botanic Gardens, 2010, p. 230

Paeonia parnassica


Perennial herbs. Tap roots columnar; lateral roots tuberous or fusiform, sometimes tandem-fusiform. Stems usually green or green but pale purple in the lower part, sparsely to densely hirsute, 30-70 cm tall, with 4-9 green or greenish yellow scales at the base. Petioles and petiolules always hirsute; lower leaves biternate, with 9, rarely 8, leaflets, usually one or several leaflets segmented and thus leaflets/leaf segments 9-15, very rarely up to 25 in number, ovate, oblong or elliptic, cuneate to rounded at the base, nearly rounded to acute at the apex, 4.5—12 cm long, 1.5-7 cm wide, glabrous above, mostly densely, less frequently sparsely, villose beneath. Flowers solitary and terminal; involucrate bracts 1-3 in number, leaf-like; sepals 3-4 in number, with one caudate and the rest rounded at the apex, nearly orbicular, 2-4 cm long, 1.5-3.5 cm wide, green but purple at the periphery or entirely purple, densely villose on the abaxial side; petals 6-8 in number, dark purple, oblong or obovate, entire or 2—lobed at the apex, 4.5-6 cm long, 3-4.5 cm wide; filaments purple; anthers purple; disk 1-1.5 mm high, waved, tomentose; carpels 1-3, but mostly 2 in number, columnar-ellipsoid, 1.4-2.2 cm long, 0.5-0.7 cm in diameter, yellowish tomentose, hairs 2 mm long; stigmas sessile, red, c. 2 mm wide.

Chromosome number: n=20 (tetraploid).

Growing at the edges and in openings of Abies forests, or in sparse Abies forests, on limestones, at an altitude of 1,100—1,500 m. Found only in the mountains Parnassos and Elikonas (Helicon) of Greece.

The most remarkable characters of Paeonia parnassica are its very dark purple petals and purple anthers, which distinguish it from P. arietina. It has fewer leaflets/leaf segments (9—15, rarely up to 25) than P. arietina (11-25, rarely up to 32).

The Peony Society also has a page about this species here.


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This species overview and synonyms on Kew Plants of the World Online: here

Source: Hong, De-Yuan. “Peonies of the World. Taxonomy and phytogeography.” Kew: Royal Botanic Gardens, 2010, p. 221-225.