Book  (2011)  Page(s) 38-39.  Includes photo(s).
 
Paeonia sterniana H.R. Fletcher, J. Roy. Hort. Soc. 84: 327, fig. 103 (1959).
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, muulti-branched, and thus many stems caespitose. Lower leaves biternate; leaflets 9, all segmented; 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 underdeveloped (sterile) buds often present, rarely 2 on a stem. Involucrate bracts 2-4 in number, leaf-like. Sepals mostly 3, rarely 4, nearly orbicular, all or mostly caudate at the apex. Petals white to pale rose, obovate, 2.3-3 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; styles less than 1 mm long, stigmas red. Follicles ovoid, ca. 3 cm long. seeds ovoid-oblong, black, lucid, 7-8 mm long, ca. 5 mm in diameter. Chromosome number 2 n = 10. Growing in forests or thickets at an altitude of 2,850-3,500 m. Confined to SE Tibet of China.

Book  (2010)  Page(s) 122-125.  Includes photo(s).
 
Paeonia sterniana....is closely related to P. emodi. They share a number of characters: the roots are 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 distincly 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...

Book  (2005)  Page(s) 26-27.  
 
Among the most important conclusions of Sang's [phylogenetic] analysis is that ...P. sterniana is a hybrid between P. emodi and P. mairei.....

In 1997 Josef Halda produced a new classification for the genus Paeonia, which created new sections and subsections and absorbed several perfectly good species into others. In Halda's classification Paeonia sterniana becomes a subspecies of P. emodi....

Book  (2005)  Page(s) 66-67.  Includes photo(s).
 
Paeonia sterniana This interesting peony was discovered in 1938, growing in the Tsangpo Valley in southeastern Tibet (Xisang). Until recently the only known plant in cultivation was growing at the Royal Botanic Garden edinburgh, but the garden distributed seed to several people in the late 1990s and it should become more readily available in the future. Ludlow and Taylor (1938), who discovered Paeonia sterniana, said that it gre to a height of 90 cm (3 ft.) in the wild, but the plant in Edinburgh is much smaller at 45 cm (18 in.). The entire plant is glabrous with deeply divided leaves, which are dark green above and glaucous beneath. Each stem produces a single white flower, approximately 5-8 cm (2-3.1 in.) across, with four lanceolate sepals and white stamen filaments. The carpels are green and glabrous with creamy white styles. P. sterniana is easy to grow, but needs well-drained soil and makes an ideal plant for the rock garden. It grows in woods at altitudes of 2800-3500 m (9200-11,500 ft.). Phylogenetic analysis suggests that Paeonia sterniana may be a hybrid between P. emodi and P. mairei (Sang, 1995).

Book  (2004)  Page(s) 201.  
 
Subspecies sterniana, a smaller version of subsp. emodi, is presumably similar [in ease of growth], but almost unknown in cultivation.

Book  (2004)  Page(s) 119, 123.  
 
Key to the subspecies of P. emodi
Flowers larger 7.5-10 cm (3-4 in.) across; leaflets entire or divided into two or three terminal leaflets.....Subsp. emodi
Flowers smaller, up to 7.5 cm (3 in.) across, leaflets more deeply lobed and toothed....Subsp. sterniana
....P. emodi subsp. sterniana (H.R. Fletcher) J.J. Halda, Acta Musei Richnoviensis 4 (2):29 (1997).
P. sterniana H.R. Fletcher in Journal of the Horticultural Society (London) 134:327 (1959).
Epithet: sterniana, after Frederick Claude Stern (1884-1967), an enthusiastic collector and gardener.
Description: Differs from subsp. emodi in having smaller, solitary flowers (up to 8 cm or 3 in. across), and deeply lobed and toothed leaflets. Flowering April to June.
Distribution: Southeastern Tibet in Kongbo, Tamnyen, and Gyala, growing among shrubs in stony places, and in shady oak forest, at altitudes from 2600 to 3000 m (8530 to 9900 ft.).
Comment: I know this plant only from a herbarium specimen. It is very closely related to Paeonia emodi. Very interesting are Fletcher's (1959) notes:
On 21 July 1938, Mr. Frank Ludlow and Dr. George Taylor were collecting in the Tsangpo Valley in the Kongbo Province of South-East tibet. Near Gyala, under the dense shade of Quercus ilex forest, they stopped for a wayside lunch and soon realized that they were sitting on a fruiting peony. The fruits were green and immature and although flowers were not to be seen, the natives affirmed that these were white. Two months later, when Ludlow and taylor returned to collect mature fruits, they found that all the seeds had been shed. Nine years later, on 18 April 1947, Mr. Ludlow and Colonel H.H. Elliot, at a place called Tamnyen, found the plant again, just coming into flower, and a week later, 24 April, they gathered beautiful flowering specimens at the spot where Ludlow and Taylor had found it originally in 1938. As the natives had affirmed, the flowers were white. Finally, at Tamnyen, on 5 August 1947, Ludlow and Elliot collected mature indigo-blue seeds from the bright red capsules.

Book  (2001)  
 
Determination key:
1 Herbs perennial; disc not well developed, annular. (2)
2 Leaflets and segments (of proximal leaves) more than 9, at least some of them segmented; carpels hairy or glabrous (3)
3 Leaflets and segments of proximal leaves more than 20, all or nearly all of them segmented, mostly less than 2 cm wide. (6)
6 Plants glabrous throughout P. sterniana

Paeonia sterniana H. R. Fletcher, J. Roy. Hort. Soc. 84: 327.
bai hua shao yao
Paeonia emodi Wallich ex Royle subsp. sterniana (H. R. Fletcher) Halda.

Herbs perennial, to 90 cm tall, glabrous throughout. Roots thick, attenuate toward tip, to 30 × 1.4 cm. Proximal leaves 2-ternate; leaflets decurrent at base; terminal leaflets segmented, segments again segmented; lateral leaflets unequally 2-segmented, segments linear-oblong or lanceolate, 5--12 × 1--2.5 cm, base cuneate, margin entire or often lobed, apex acuminate; segments and lobes up to 40. Flowers solitary, terminal, single, 8--10 cm wide, sometimes underdeveloped flower buds also present in axils of distal leaves. Bracts 3 or 4, leaflike, unequal. Sepals 3 or 4, ovate-orbicular or orbicular, 2--2.5 × 1.5--2 cm, apex mostly caudate. Petals white or pale pink, obovate, ca. 3.5 × 2 cm. Filaments yellow. Disc yellow, annular. Carpels 2--4, green, glabrous. Stigmas red-purple. Follicles ovoid, 2.5--3 × ca. 1 cm. Fl. May, fr. Sep.
* Woods; 2800--3500 m. SE Xizang [Tibet].

Book  (Jan 2000)  Page(s) 65.  
 
Paeonia sterniana Fletcher
Moost appropriately named to honor F. C. stern, this species was discovered in southeast Tibet at the 9500-foot elevation and brought to the West in 1947, from seeds and plants collected by Ludlow and Elliott. It reaches a height of 36 inches. The leaves are alternate and biternate, the many leaflets segmented, narrow, and elliptic. The solitary flowers are to 3 inches across; the petals are white, thin, and papery. Though at one time it was found in a few gardens in Great britain, the plant appears to be extremely rare in cultivation. Chromosome number unknown.

Book  (Jan 1999)  Page(s) 26, 28.  Includes photo(s).
 
Page 26: Paeonia sterniana was collected by Frank Ludlow in the Tsangpo Valley in southeast Tibet at an altitude of about 9,500 ft (3,000 m). it is not unlike P. emodi but there is just one flower with white, tissue-paper petals to each stem. Blue seeds bursting out of bright red capsules add excitement in autumn. Unfortunately, it is not commercially available
Page 28: [Photo] Paeonia sterniana. In autumn the seed capsules turn scarlet and then burst to reveal blue seeds.

Article (magazine)  (1997)  
 
p.1131 [Authors present in Fig. 7 a Phylogeny of Paeonia section Paeonia reconstructed from a synthesis of the ITS and matK phylogenies.....P. sterniana is shown as hybridization from P. emodi and P. mairei, inheriting fully additive ITS sequences from both parent species, cpDNA inherited being inherited from P. emodi and ITS sequences fixed from P. mairei. Diploid.