F.C. Stern A Study of the Genus Paeonia

1. P.suffruticosa Andrews, Bot. Reg.6, t. 373 (1804) ; Joh. Kemer, Hort. Sempervir. t. 229 (1806), t. 530 (1819) fide Index Londinensis ; Bailey, Stand. Cycl. Hort. 5, 2434 (1916) ; Rehder, Man. Cult. Trees and Shrubs, 214 (1927) ; Terasaki, Nippon Shokubutsu Zufu (Jap.Bot. 3, Album), t. 286 (1933) ; F. C. Stem in Journ. Roy. Hort. Soc. 68,124 (1943).Syn. P.suffruticosa var. hibernifiora Makino in J. Jap.Bot. 3, No. 9, P.36 (1926) ; Makino & Nemoto, Nippon-Shokubutsu-Soran (Fl. Japan), Ed. 2, P.332 (1931). P.suffruticosa var. papaveracea (Andrews) Joh. Kemer, Hort. Sempervir. t. 473 (1816) fide Index Londinensis; Bailey in Rhodora, 18, 156 1916).P.suffruticosa var. purpurea Andrews, Bot. ReP.7, t. 448 (1807). P.arborea Donn, Cat. Hort. Cantab. Ed. 3, P.102 (1804), nomen subnudum ; Joh. Kemer, Hort. Sempervir. t. 645 (1822) ; Gartenflora, 8, t. 246 (1859) ; Schneider, 111. Handb. Laubholzk. 1, 271, fig. 181 (1904) ; Bull. Soc. Dendr. France, 1913, P.157, fig. 54. P.arborea var. papaveracea (Andrews), Schneider, 111. Handb. Laubholzk. 1, fig. 180 (1904). P.Moutan Sims in Bot. Mag. t. 1154 (1808) ; Alton, Hort. Kew, Ed. 2, 3, 315 (1811); DC. Syst. I, 387 (1817); Anderson in Trans. Linn. Soc. London, 12, 254 (1818) ; Smith in Rees, Cycl. 1 (1819) ; Bot. Reg. t. 379 (1819), t. 1678 (x835) ; Sabine in Trans. Hort. Soc. London, 6, t. 7 (1826) ; Miquel, Prod. Fl. JaP.197 (1866-67) ; Franchet & Savatier, Enum. PI. JaP.1, 14 (1874) ; Baker in Gard. Chron., N. Ser. 21, 779 (1884) ; Lynch in Journ. Roy. Hort. Soc; London, 12,432, fig. 22, 23 (1890); Huth in Engl. Bot. Jahrb. 14,272 (1891) ; Bretschneider, Hist. Ew. Bot. Exfil., China, 191, 204 et al. (1898) ; Diels in Engl. Bot. Jahrb. 29, 324 (1900) ; Finet & Gagnepain in Bull. Soc. Bot. France, 51, 534 (1904), et Contrib. Fl. Asie Or. 1, 221 (1905) ; Farrer, Eaves of the World, 110-113, ii5, 127, i62 (1917) ; Bean, Trees and Shrubs, Ed. 3, 2, 120 (1921).P.Moutan subspecies atava Brühl in Ann. Bot. Gard., Calcutta, 5, ii, 114, t. 126 (1896). P. Moutan var. Hemsleyana King MS. in Herb., Calcutta.P.Moutan var. papaveracea (Andrews), DC. Syst. 1, 387 (1817) ; Sims in Bot. Mag. t. 2175 (1820) ; Loudon, Arb. et Frut. Brit. 1. 250 (1838).P.papaveracea Andrews, Bot. ReP.7, t. 463 (1807).For further references the reader is referred to the Index Londinensis. Many garden forms have received names, but they are all included within the scope of P.suffruticosa.

Description. A shrub, up to 2 m. high ; stems glabrous. Leaves bipinnate ; lateral leaflets 4.5-9 cm. long, 3.2-5 cm. wide, shortly stalked or sessile, more or less ovate in oudine, palmately coarsely 3-5 dentate or lobed ; terminal leaflets deeply and incisely divided into 3 lobes, side lobes entire, 5-6 cm. long, 2-2.5 cm. wide, terminal lobe coarsely 3-toothed, 7-8.5 cm. long by 3-2.4 cm. broad, apex of lobes and teeth sharply acute, bright green above, glaucous below with few long hairs scattered along the midrib and main nerves, and with white hairs at the junction of rachis and petiole. Flowers rose-pink to white, with a deep magenta blotch edged red at the base, 16 cm. across. Petals numerous, 9 cm. wide, concave, orbicular-obovate with the apex truncate and notched, irregularly crenulate. Stamens 3 cm. long, filaments magenta, deeper coloured at the base and white towards the top; anthers yellow, 0-5 cm. long, pollen yellow. Carpels 5, green, with white stigma, at first completely enclosed in a thin, leathery, corrugated, white sheath-like outgrowth from the disc, which splits open as the carpels develop.




Distribution. china : Kansu, in gardens at Choni Lamasery, J. F. Rock (K) ; near Wang Kia Wan, Licent 1006 (K) ; Szechwan, near Tatsien-lu, Pratt 768 (K). tibet : " Llohung " [Lhalung], 4250 m., J. C. White (C) ; Chumbi, Tuk Chang, King's Collector, 549 (K). bhutan : Chang-na Na to Paro, 2360-2930 m., Gould 132 (K).

Paeonia suffruticosa is a name which covers all the garden forms of the large-flowered tree paeonies of China and Japan which have been grown in English gardens since Sir Joseph Banks introduced the first plants in 1787. The home of the wild plants has only recently been discovered ; the full history of their introduction to Europe and of the exploration which led to the discovery of their habitat, is given on page 16. 40[end page 40]

P.suffruticosa belongs to the Section MOUTAN, which comprises all the tree paeony species, and is subdivided into two subsections—vaginatae and delavayanae. The species of subsection vaginatae to which P.suffruticosa belongs is characterised mainly by the disc being produced as a thin leathery sheath which at first completely envelops the carpels and by possessing some hairs on the lower surface of the leaves. The species belonging to the subsection delavayanae lack this sheath and are completely glabrous.

Most specimens in herbaria are garden plants, but there are a few specimens which may have been wild, collected by Licent and Pratt in China and also wild specimens collected by Purdom, also in China, which have been named by Rehder P.suffruticosa var. spontanea.

All these come from S.W. Kansu and the districts near Tatsien-lu in Szechwan and in the province of Shansi.

There are also two specimens in the Calcutta herbarium of P.suffruticosa from northern India and Tibet collected by Indian collectors in 1884 and 1906, which are named P.Moutan subspecies atava. (See page 16.)

The specimens mentioned above fall into two varieties—

A.—P.suffruticosa with leaflets deeply and incisely divided and the apex of the lobes and teeth sharply acute.

B.—P.suffruticosa var. spontanea with leaflets more or less unequally trilobed with the sinus rounded and the apex of the teeth blunt.

Under P.suffruticosa come the garden forms of Chinese and Japanese origin, and also Licent 5006 and Pratt 768, while P.suffruticosa var. spontanea includes Purdom's specimens and Licent 1909.

The description given above was made from a specimen, now in the Kew Herbarium, of a plant raised from seed sent by Dr. J. F. Rock from Choni in Kansu. It flowered in my garden at Highdown in 1938. Dr. Rock's story of this plant growing in the Lamasery at Choni is given on page 16. Seeds of these plants were distributed to different gardens in the United States, Canada, Sweden and Great Britain, and all the seedlings were alike ; and as these plants agree with the description of the wild plants given by Farrer (1914) it may be that Rock's paeony represents the true wild species. It has the same characters as the various garden varieties of P.suffruticosa, though the leaflets in some of the garden-grown specimens are broader ; it is also very like the plant which Andrews described as P.papaveracea and illustrated in the Botanists Repository (loc. cit.), the only difference being in the colour of the sheath surrounding the carpels which Andrews described as purple, while in Rock's plant it is white.

With regard to the specimens at Calcutta named P.Moutan, subspecies atava, one specimen, " No. 549 Tuk Ghang 23.6.1884," has smaller leaflets and flowers than P.suffruticosa. The lateral leaflets measure 2-4 cm. long and 1-2 cm. wide, terminal leaflets 3-4 cm. long by 2-3 cm. wide ; the flowers also are about 10-11 cm. across and have fewer petals.

This specimen does not appear to be a distinct variety but merely a form of P.suffruticosa. Although Dr. Brühl when he described the specimen said " there appears to be no doubt about it growing wild in the Chumbi Hills," there is in my mind a doubt whether this tree paeony could be indigenous to a place so far removed from the restricted habitat of the species in western Central China. There is always the possibility that these plants were escapes from monastery [end page 41] gardens since the monks are known to be fond of growing the tree paeonies. I am indebted to Dr. K. Biswas, the Curator of the Herbarium at the Royal Botanical Gardens, Sibpur, Calcutta, for his kindness in sending the specimen to Kew for me to examine.

Rock's paeony is a great acquisition to the garden, with its attractive large white flowers bearing maroon blotches at the base of the petals. It is perfectly hardy and easy to cultivate. [end page 42]