Article (magazine)  (2001)  
 
KEY TO SPECIES
1. Flowers solitary, erect; disc leathery, sheathing the carpels to at least half their length (Section Moutan DC.): 2
2. Carpels 5(-7), tomentose, more or less entirely sheathed by the disc; leaves biternate or 2-3-pinnate, leaflets 9-33: 3
3. Shrubs often at least 1.5 m tall; leaves more or less 2 - 3-pinnate, leaflets 11-33, ovate to lanceolate; flowers comparatively large, more than 10 cm in diameter: 5
5. Leaflets rarely more than 15, entire or deeply 2-3-lobed; petals unblotched: 3. P. ostii

5. Paeonia ostii T. Hong & J. X. Zhang, Bull. Bot. Res. (Harbin) 12 (3): 223, fig. 1 (1992). Typus: China, Zhengzhou Institute of Aeronautical Industrial Management, Arboretum of Rare and Endangered Trees, introduced from Mt. Yangshan of Songxian, Henan Province.....P. suffruticosa subsp. ostii (T. Hong & J. X. Zhang) J. J. Halda, Acta Mus. Richnov., Sect. Nat., 4 (2): 30 (1997); P. suffruticosa subsp. yinpingmudan D. Y. Hong, K. Y. Pan & Z. W. Xie, Acta Phytotax. Sin. 36 (6): 519, fig. 2, pl. 2.......Shrub to about 1.5 m tall. Leaves biternate or bipinnate with three pinnae, leaflets 9-15, more or less lanceolate with acuminate tip, entire or sometimes 2-3-lobed, greyish-green, especially when young. Flowers large (c. 15 cm diam.), single, petals white, often flushed with purplish-pink, unblotched, disc dark reddish-purple.
Recorded as growing wild in Henan, Anhui, Hunan and Shaanxi, but possibly now extinct as a genuinely wild plant except in western Henan. Perhaps still common in cultivation, especially in Anhui, but many cultivated plants similar in appearance to this species may be hybrids between it and P. X suffruticosa. Plants cultivated under the name 'Feng Dan Bai' (='Phoenix White') may be the true species, but at least some appear to be hybrids.

Book  (Jan 2000)  Page(s) 49.  
 
The four species described by Hong and his associates are as follows:
...Paeonia ostii Hong and Zhang
Named for the Italian specialist, "Osti's peony" is the endangered and very precious wild woody peony species endemic in China, found in the provinces of Gansu, Shanxi, and Anhui. It grows to 5 feet and has lanceolate leaflets; the terminal leaflet occasionally has three lobes. The flower, which lacks basal blotches or flares, is entirely white, or white tinged with pink. The filaments, disc, and style are purplish red. Diploid (10 chromosomes).

Book  (Jan 2000)  Page(s) 18.  Includes photo(s).

Book  (Jan 1999)  Page(s) 19-20.  
 
Paeonia ostii now an endangered species. Named after the Italian botanis Dr. Gian Osti... pure white sometimes faintly tinged with pink... Like P. jishanensis it has purplish-red filaments, disc and style.