F.C. Stern A Study of the Genus Paeonia
22. P.obovata Maxim var. Willmottiae (Stapf) F.C. Stern, var. nov. in Journ. Roy. Hort. Soc. 68, i28 (1943).Syn. P.Willmottiae Stapf in Bot.Mag. t.8667 (1916) ; Gard.Chron.,Ser.3, 65, 258, fig.123(1919) ; Garden, 83, 256, cum fig.(1919), 84,350, cum fig. (1920).
Description. Stem 56 cm. high, glabrous. Lower leaves biternate ; leaflets obovate to broadly oval or ovate, cuneate at the base, shortly contracted to the acute apex, 6-15.5 cm. long, 4.2-8.5 cm. broad, papery, dark green and glabrous above, glaucous and villous beneath. Flowers about 10.5 cm. across. Petals obovate, white, 5-5.5 cm. long, 3-3.5 cm. broad. Stamens about 1-5 cm. long, filaments reddish, anthers golden. Carpels 3-5, glabrous, narrowly conical, attenuated to the prominent stigma, in all 1.7-2 cm. long. Follicles 2.5-3.5 cm. long.
Distribution. china : Shensi, Ta-pai-shan, Giraldi (K). Hupeh, Patung, Henry 53650 (K) ; Hsingshan, Henry 53655 (K) ; Fang, Wilson Veitch Exped. 631 (K) ; near Ichang, Wilson Arn. Arb. Exped. 359 (K) ; Shin shan hsien, Chien 8350 (K).
P.obovata var. Willmottiae has only been found in one comparatively small district in western China on the borders of West Hupeh and Szechwan, and was described first as P.Willmottiae by Stapf (1916). In this article he said it differed from P.obovata by the larger leaflets, which are villous below, by the larger white flowers and by the length of the pistil. On these characters he raised it to the rank of a species. Apparently he described it from a garden plant which flowered in Miss Willmott's garden at Warley Place, Essex, some time before 1914. There are good specimens collected in western China by Henry, Giraldi and Wilson, in the herbaria at Kew and Edinburgh. On examining these wild specimens the one character in which they differ from P.obovata is the amount of hairy tomentum on the back of the leaves. The leaflets on an average do not appear to be larger than those of P.obovata nor does the pistil appear to be longer, though the carpels are more attenuated than are the carpels of P.obovata. The flowers are slightly larger and, so far, only white flowers have been reported. In cultivation P.Willmottiae grows larger than P.obovata in height and in all its parts and is a more robust plant; it appears out of the ground earlier and flowers before P.obovata alba, which is the only form of P.obovata now in cultivation as far as I know. The unusual habit of the leaves, to grow again after the plant has finished flowering, is even more pronounced in the variety Willmottiae than in P.obovata. The terminal leaflet broadens in width from 5-3 cm. to 6-3 cm. and in a lateral leaflet from 4-6 cm. to 8"] cm. To show how this curious growth appears on a plant of this species growing in the garden, the following measurements of the two lower leaves of a plant were taken :
(1) Lower leaf when plant was in flower, May 10, 1939leaflets 4.5-6.6 cm. by 3-4.5 cm. (the laterals of the two lower sets of threes) to 8-10 cm. by 4.4-6.3 cm. ; petiolules of the middle leaflets 1-2 cm. long.
(2) Lower leaf when the plant was in fruit, July 24, 1939leaflets 8.5 cm. by 7-8 cm. (the laterals of the two lower sets of threes) to 14-17 cm. by 8.6 cm. ; petiolules of the middle leaflets 1.5-2.7 cm. long.
The dried specimen is in the Kew Herbarium.
The only differences between this plant and P.obovata appear to be the villous undersides of the leaf, the larger size of the flower and the earlier time of flowering. These characters do[end page 76] not, in my opinion, seem to be sufficiently important to constitute a species but are rather varietal; therefore it would be better to regard it as a variety of P.obovata coming from one particular geographical district and adopt Stapf's specific name Willmottiae as the varietal name. This variety is a tetraploid like the species.
This is one of the most beautiful paeonies for the garden. It flowers in the first days of May with a charming white, cup-shaped flower enclosing a mass of golden stamens. Unfortunately it is not very easy to grow but it appears to do best in a good loam in a position facing west. It seeds freely. [end page 77]