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 (17-) 19-33; petals with a prominent dark purple basal blotch: 4. P. rockii

5. Paeonia rockii (S. G. Haw & L. A. Lauener) T. Hong & J. J. Li ex D. Y. Hong, Acta Phytotax. Sin. 36 (6): 539 (1998). Typus: China, Kansu.... P. rockii T. Hong & J. J. Li, Bull. Bot. Res. (Harbin) 12 (3): 227, fig. 4 (1992), nom. inval. (lacking exact page reference of basionym); P. suffruticosa subsp. rockii S. G. Haw & L. A. Lauener, Edinb. Journ. Bot. 47 (3): 279, fig. la (1990)....P. suffruticosa 'Rock's Variety' ('Joseph Rock') hort..... Shrub to about 2 m tall. Leaves more or less triternate or 2-3-pinnate, with 19-33 leaflets, rarely less than 19 but always more than 15. Flowers very large (15-20 cm diam.), single; petals white, sometimes flushed with pink, with a conspicuous deep purple basal blotch, disc whitish.

KEY TO SUBSPECIES
Leaflets lanceolate to ovate-lanceolate, often entire or sometimes 2-3-lobed:
5a. P. rockii subsp. rockii. P. rockii subsp. linyanshanii T. Hong & G. L. Osti, Bull. Bot. Res. (Harbin) 14 (3): 237, fig. 1 & 2 (1994); P. suffruticosa subsp. rockii S. G. Haw & L. A. Lauener var. linyanshanii (T. Hong & G. L. Osti) J. J. Halda, Acta Mus. Richnov., Sect. Nat., 4 (2): 30 (1997). ...Leaflets lanceolate or ovate- lanceolate, entire or sometimes 2-3-lobed. ...Southern Gansu, southern Shaanxi (on the southern slopes of the Qinling Mountains), Henan (Funiu Mountains) and western Hubei.

Leaflets ovate to suborbicular. mostly 2-5-lobed:
5b. P. rockii subsp. taibaishanica D. Y. Hong. Acta Phytotax. Sin. 36 (6): 542, fig. 2 (1998). Typus: China, Shaanxi, Mt Taibai, Shangbaiyun, alt. 1750 m., in broad-leaved deciduous forest on cliff, 24 v 1985...Leaflets ovate to suborbicular, mostly 2-5-lobed..... Found only on the northern slopes of the Qinling Mountains in southern Shaanxi and Gansu. Reported to have been common on Mt Taibai in the 1960s, but now scarce.

Book  (Jan 2000)  Page(s) 49.  Includes photo(s).
 
The four species described by Hong and his associates are as follows:
....Paeonia rockii (Haw and Lauener) Hong and J. Li
The same plant that is familiar to many under the name Paeonia suffruticosa 'Rock's Variety' or P. suffruticosa 'Joseph Rock'. The shrub, often 5-6 feet tall, has deeply divided leaflets and large white flowers, with a purple blotch on the base of each petal. The filaments, disc, and style are white. Diploid (10 chromosomes).

Book  (Jan 2000)  Page(s) 48.  
 
Some time after 1925, Joseph F. Rock sent back to the Arnold Arboretum in the United States seed from what he believed was a wild form of the species, in spite of the fact that he gathered it from a plant tended in a lamasery garden in Zhoni, Gansu Province. Plants from this seed have been quite widely cultivated under the name P. suffruticosa 'Rock's Variety' or 'Joseph Rock', both now known as P. rockii.

Book  (Jan 2000)  Page(s) 17, 19.  Includes photo(s).
 
Page 17: [Photo]
Page 19: [Photo]

Book  (Jan 1999)  Page(s) 633.  Includes photo(s).
 
Paeonia suffruticosa subsp. rockii semi-double white flowers with a maroon blotch at the base of each petal

Book  (Jan 1999)  Page(s) 20, 22, 23.  Includes photo(s).
 
Page 20: Paeonia rockii or another almost identical tree peony reached Europe from China as a garden plant on Captain James Prendergast's ship Hope in 1802. It seems not to have been named. It was first recorded in the wild in 1914 [by] Reginald Farrer, the English plant hunter, writer and artist... as a form of Paeonia suffruticosa... identified by Hong Tao... rediscovered in 1926 growing in a Tibetan monastery in south west Gansu by the American collector Dr Joseph Rock... white petals bruised at their bases with deep black-maroon blotches, surrounding a crown of golden-yellow anthers on purple and white stamens... Rock's find was celebrated as P. suffruticosa 'Rock's Variety' or P. s. 'Joseph Rock'... It is now generally agreed that Paeonia rockii is a species in its own right...
Page 22: [Photographed at Highdown, Sussex] one of the plants Sir Frederick Stern raised from seed collected in China by Joseph Rock
Page 23: not easy to grow or propagate, and young plants are rare and expensive

Article (magazine)  (Jan 1955)  Page(s) 15.  
 
About 1932, the explorer, J. F. Rock, collected in a Lamasery seeds of what he believed to be a wild peony from Kansu. The resulting plants flowered in America, Canada, Great Britain, and Sweden about 1938. They were like P. papaveracea of Andrews except that the sheaths enclosing the carpels were white, not purple. Apparently there have been no introductions of Moutan peonies from China since 1932.