F.C. Stern A Study of the Genus Paeonia

7. P.Brownii Douglas ex Hooker, Fl. Bor.-Amer. 1, 27 (1829) ; Torrey & Gray, Fl. N. Amer. 1, 41 (1838) ; -Bot. Reg. 25, t. 30 (1839) ; Baker in Gard. Chron., N. Ser. 21, 779 (1884), pro parte; Lynch in Journ. Roy. Hart. Soc. 12, 433, fig. 24 (1890) ; Greene in Gard. and For. 3, 356 (1890), et Fl. Francis. 307 (1892) ; Huth in Engl. Bot. Jahrb. 14, 273 (1891) ; Gray, SynoP.Fl. N. Amer. Ed. Robinson, 1, 56 (1895), pro parte ; Howell, Fl. N.W. Amer. 1, 27 (1897) ; Douglas, Journal Trav. JV. Amer. 64, 333 (1914) ; Jepson, Fl. Calif. 5, 515 (1914), et Man. Flow. PI. Calif. 373 (1923) Pro parte; Saunders in Nat. Hort. Mag. 13, tab. P.215 (1934) ; St. John, Fl. S.E. Wash. and Adj. Idaho, 153 (1937) ; Stebbins in Madroño, 4, 252-260, t. 37 (1938) ; F. C. Stem in Journ. Roy. Hort. Soc. 68, 124 (1943).Syn. P.sp.Douglas, Journal Trav. N. Amer. 192, 197, 20i, 268 (1914).

Description. Stems 24-43 cm. high, glabrous. Leaves 5-7, biternate, with the leaflets shortly stalked ; leaflets divided to the base into 3 segments ; segments deeply divided, 3- to 4-lobed ; lobes entire or lobulate or toothed, apex of lobes rounded to obtuse, with a very short point; leaflets fleshy, with a strong marginal nerve, glabrous, dark green above, and glaucous below. Flower subglobose, not opening widely, 2-3 cm. across. Sepals broad ovate to suborbicular, I-2-2 cm. long, i-2-i cm. wide, coriaceous. Petals broad oval to suborbicular, 9-14 mm. long, 7-16 mm. wide, thinly coriaceous, dark maroon. Stamens about i cm. long, filaments yellowish, anthers yellow. Carpels 5, glabrous. Disc surrounding the base of the carpels fleshy, lobed, 2-5-3 mm. high. Follicles erect or slightly spreading, 2.5-3 cm. long, 1.5-1.8 cm. wide.



Distribution. northern california, States of washington, oregon and nevada.

washington : Mt. Adams, J. W. Thompson (K) ; Panther Creek, Amador Co., 1460 metres, Hansen (K). oregon : near the confines of perpetual snow on the subalpine range of Mt. Hood, Douglas, June-July 1826 (K) ; on the alpine region of the Blue Mountains, on the verge of perpetual snow, Douglas, July 1826 (K) ; Blue Mountains, Howell (K); Columbia River, Douglas 1830 (K) ; Dalles, Lyall (K) ; dry summit of high ridge 15 miles S.E. of The Dalles, Wasco Co., J. W. Thompson 4118 ; high hills 30 miles east of Medford, Jackson Co., Heckner (K) ; Rock Creek, Morrow Co. 1040 metres, Leiberg 55 (K) ; Grand Ronde Prairie, Nuttall (K) ; Rogue River Valley (K); sine loc. Cusick sigi (K), nevada : Fish Lake, above Marmol Station, Washoe Co. 1670 metres. Heller gggy (K). california : Bear Valley, Sacramento Mountains, mountains of San Antonio, Hartweg 1636 (398) (K) ; American Valley, Plumas Co., Austin 42 (K) ; Sierra Nevada near Lake Tahoe, 1820 metres, J. Ball (K) ; San Hedrin, Coast Ranges, 1700 metres, Purpus 1062 (K) ; sine loc. Bigelow (K).

P.Brownii and P.californica of western America are herbaceous paeonies which constitute a distinct section of the genus onaepia, Lindley ; the species of this section are characterised by small petals, by a very prominent disc usually divided into separate segments, and by cylindrical rather than ovoid seeds. The only other species that have these prominent discs are the shrubby paeonies of China, which belong to the section Moutan.

P.Brownii is found in the districts of northern California as far north as the State of Washington and as far east as Wyoming, mostly at 3000 to 6000 ft. ; P.californica is found in southern and south central California from sea level to 4000 ft. The location of these paeonies is taken from the article on these western American paeonies by G. Ledyard Stebbins, jun. (1938).

P.californica differs from P.Brownii by its greater stature, by its larger leaflets, which are green on the underside, the segments being incisely divided, not lobed with the segments, and lobules narrower, more oblong and acute at the apex and by its longer petals which are slightly longer than the sepals. According to Torrey and Gray (1838) P.Brownii flowers in June and July, and P.californica in March and April. Mr. Stebbins draws attention to the range of these two paeonies, saying that in his opinion P.Brownii with the northerly distribution is hardy, while P.californica with the more southern range is not hardy.[end page 51] Many botanists have considered these two paeonies to belong to the same species, with one a variety of the other. The greater luxuriance of P.californica was considered due to its geographical position. Nuttall, whose description is given by Torrey and Gray, was the first to separate them into two species, naming the southern paeony P.californica. Lynch (1890) gave this paeony the varietal name of P.Brownii var. californica, considering that the only differences from the northern paeony were the leaf colour and shape of leaf segments. The reasons given by Nuttall for separating the two paeonies into two species, except for the green and glaucous leaves, do not seem to be valid. Stebbins has made an intensive study over several years of these paeonies and grown them together at the University of California, at Berkeley. In his paper (1938) he gives a table comparing the two species and comes to the conclusion that the northern and southern forms should be considered two distinct species. As he says, specimens of the two species in the herbarium can be easily separated, but it is not so easy to define the differences between them. But further evidence has been produced by the cytological examination of these paeonies, described in the paper by Stebbins and Ellerton (1939). They show that these two paeonies are cytologically quite distinct from other paeony species and that P.Brownii exhibits the cytological peculiarities to a more extreme degree than P.californica, which they consider more closely approaches the Old World species in its cytological as well as its morphological characteristics.

Few specimens of these paeonies are to be found in European herbaria, and on examining these one would at first contend that these paeonies from North America, the only representatives of the genus on the American continent and so different morphologically from the Old World species, were varieties of one species, the most luxuriant form coming from the more southern range and the less well developed forms coming from the northerly districts and higher levels ; but in view of the morphological differences and the cytological difference between these two forms cited above, I think that the classification nearest the truth would be to divide the American paeonies into two species, P.Brownii and P.californica.

P.Brownii is not an attractive plant for the garden and it is difficult to keep alive in cultivation. It comes up from seed quite easily but then generally dies away.[end page 52]