A deciduous shrub 3 to 6 ft high, devoid of down in all its parts. Leaves doubly pinnatifid, the ultimate divisions lanceolate, slender-pointed, 2 to 4 in. long, dark green above, glaucous beneath. The entire leaf with its stalk is from 6 to 18 in. long and it persists in its dead condition through the winter. Flowers one to three on a stalk, each 21⁄2 to 4 in. wide, cup-shaped, rather drooping, opening in June. Each flower has an involucre of leafy bracts set close against the five greenish sepals. Petals five to ten, rounded, incurved, overlapping, of a rich, almost blood red, their beauty heightened by the clustered golden anthers in the centre. Seed-vessels 3⁄8 to 11⁄4 in. long, glabrous.
Native of China; originally discovered by the Abbé Delavay in 1884; introduced by Wilson about 1908. It is related to P. lutea, differing mainly in the colour of the flowers. Still, Forrest records that he found numerous plants in W. China with flowers of an indeterminate colour between red and yellow, sometimes orange-brown, which gave him the impression that they might be hybrids between the two species. Some of this mongrel type reached cultivation, but they are very inferior to the type described above. P. delavayi is a handsome shrub seen at its best, although it has the defect when small of hiding the face of its flowers. It likes a rich soil with occasional dressings of manure and succeeds well in chalky districts. Unlike P. suffruticosa, it does not appear to suffer from late spring frosts.
In the USA some hybrids with dark red flowers, deriving from P. delavayi, were raised by Prof. A. P. Saunders, and are classified by American growers with the Lutea hybrids (see under P. lutea). Of these, ‘Black Pirate’ received a First Class Certificate in 1959 when shown by Sir Frederick Stern, but is scarce in this country. The flowers are single, maroon-crimson (Journ. R.H.S., Vol. 88 (1959), fig. 118).
P. potaninii Komar. P. delavayi var. angustiloba Rehd. & Wils. – This differs from P. delavayi in its smaller flowers, which lack a foliaceous involucre, in its much more dissected leaves with narrower segments, and in its suckering habit. Native of W. Szechwan and N.W. Yunnan. It was introduced by Wilson in 1904 and first flowered in Veitch’s Coombe Wood nursery in June 1911. A handsome shrub in regard to its foliage but inferior to P. delavayi in its flowers, which are about 2 in. wide. It grows to about 2 ft in height and spreads by underground stolons.
f. alba F. C. Stern P. delavayi var. alba Bean – Flowers creamy white; stamens with green filaments.
var. trollioides (Stapf ex F. C. Stern) F. C. Stern P. trollioides Stapf ex F. C. Stern; P. forrestii Hort. – This has yellow, trollius-like flowers and is of more erect growth than typical P. potaninii, with the flowers held above the leaves. Introduced by Forrest from Yunnan in 1914 (F.13195). It flowers end-May.