A deciduous shrub up to 4 ft high, with a shreddy bark; young stems hairy; stipules brown, ovate or ovate-lanceolate, acute, more or less glabrous except for a tuft of hairs at the apex. Leaves with usually five leaflets, arranged as in P. fruticosa; leaflets of firm texture, oblong-elliptic or oblong-obovate, about 3⁄8 in. long, mucronate at the apex, glabrous on both sides except for scattered hairs on the margins, dark green and lustrous above, undersides with a dense venation as in P. arbuscula, the midrib and laterals not prominent. Flowers white (or sometimes pale yellow), 3⁄4 to 11⁄4 in. wide, solitary, in few-flowered cymes, or occasionally in cymose panicles; pedicels hairy. Bractlets of outer calyx elliptic or obovate, shorter than the sepals. Other floral characters as in P. fruticosa. Bot. Mag., t. 3676.
Native of Russia from E. Siberia to the Pacific, N. and W. China, E. and S.E. Tibet; introduced in 1822 by Loddiges, who received seeds from St Petersburg. In its typical, glabrous state P. davurica is rare in cultivation, but there is a very dwarf, compact form in commerce which agrees well with it but rarely flowers. It is allied to P. arbuscula, both species typically having relatively broad leaflets with a closely meshed venation. But both species have forms or varieties in which this character is lacking. As in P. arbuscula, the hairs on the midrib beneath, petiole and stem, when present, often have a swollen base.
The plants called ‘Farrer’s White’, of which there are at least two clones, were raised from seeds collected by Farrer in S.W. Kansu, probably under his field number 460. These differ from typical P. davurica in having the leaflets sparsely hairy, rather thin, with a lax venation. A form of P. davurica introduced by Purdom from Shensi is also not typical but approaches the var. veitchii – the name under which it is figured in Bot. Mag., t. 8637.
In Yunnan and in other parts of W. China and S.E. Tibet a form of P. davurica occurs in which the calyx is brilliantly suffused with red. This variant was named var. rhodocalyx (under P. glabra), but unfortunately this name is illegitimate for technical reasons. In some Yunnan plants the red calyx is combined with a nodding, bell-shaped flower – a character beautifully captured by Forrest’s specimen 23117 in the Kew Herbarium. Cultivated plants of this form, believed to have been raised from Forrest 28574, show the red calyx quite well in some seasons, but it is not a constant character. Some of these plants have the flowers cream-coloured when they first expand and in (P. glabra var. rhodocalyx) ‘Ruth’ they keep that colour even when open. Such plants could be referable to P. × sulphurascens (see below), but they do not show any other sign of hybridity. We are not obliged to assume that P. davurica invariably has pure white flowers.
var. mandshurica (Maxim.) Wolf P. fruticosa var. mandshurica Wolf; P. glabra var. mandshurica (Maxim.) Hand.-Mazz.; Dasiphora mandshurica (Maxim.) Juz. – A dwarf shrub with leaves resembling those of the type in texture and venation but with somewhat wider leaflets, which are coated on both sides with appressed silky hairs. It was described from Olga Bay, near Vladivostok, in 1873, but had been found by the Kew collector Charles Wilford in 1859 farther up the coast. In the Wilford specimen the leaflets of the lower pair are 1⁄2 in. long, 1⁄4 in. wide. This variety is not confined to the coast. It was collected by Komarov on the upper Yalu river in N.E. China, and according to Handel-Mazzetti plants matching the Wilford specimen occur in Korea, and in China as far south as the Muli region of S.W. Szechwan. In Plantae Wilsonianae, it is said to be not uncommon in the dry valleys of N.W. Szechwan, but the specimen cited – W.3172 – is very different from typical var. mandshurica, judging from the duplicate in the British Museum. See also ‘Manchu’, in the section on garden varieties.
The status of Makino’s P. fruticosa var. leucantha is uncertain. It occurs in Japan in Shikoku, where it is the only shrubby cinquefoil, and also on the main island. Rehder places it under var. mandshurica, to which it is near geographically.
var. subalbicans (Hand.-Mazz.) P. glabra var. subalbicans (Hand.-Mazz.) Hand-Mazz.; P. fruticosa var. subalbicans Hand.-Mazz. – A robust variety of P. davurica with short-stalked flowers borne numerously in dense cymes; bractlets of outer calyx mostly oblong-lanceolate and longer than in typical P. davurica. In the type (Licent 4100 from Kansu), the leaves are silky above and coated beneath with a very dense silky tomentum. There are plants in cultivation which agree with this variety in flower and inflorescence, but not in their foliage, which is only sparsely hairy. One is grown as P. fruticosa var. hersii (an unpublished name) and the other actually as P. fruticosa var. subalbicans. Both have broad, dark green leaflets, with the close venation of typical P. davurica, and are free-flowering. The former was presumably raised from seeds collected by the Belgian engineer Joseph Hers.
f. ternata (Cardot) P. fruticosa var. davurica f. ternata Cardot; P. glabra f. ternata (Cardot) Hand.-Mazz.; P. fruticosa var. tangutica Wolf, teste Hand.-Mazz. – Leaves trifoliolate. Calyx sometimes flushed with red. Described from a specimen collected by the French missionary Soulié on the Mekong-Salween divide. Handel-Mazzetti gives P. fruticosa var. tangutica Wolf as a synonym – a variety described from specimens collected in Kansu and N.E. Tibet, with trifoliolate leaves and large flowers with a red-tinged calyx. Wolf supposed the flowers to be yellow, and it may be that he was right, since similar plants with yellow flowers have been collected in S.E. Tibet and could represent either a yellow-flowered form of P. davurica or a glabrous form of P. arbuscula. However, Handel-Mazzetti saw Wolf’s type-specimens and concluded that at least one definitely had white flowers.
var. veitchii (Wils.) Jesson P. veitchii Wils.; P. glabra var. veitchii (Wils.) Hand.-Mazz.; P. fruticosa var. veitchii (Wils.) Bean – Leaflets hairy on both sides, as in var. mandshurica, but not so firm in texture and with the lateral veins prominent on the undersurface. The bractlets of the outer calyx are longer than in typical P. davurica and its Manchurian variety, about equalling the calyx in length. It is also more robust, growing to about 5 ft in height. The var. veitchii is a native of W. Hupeh, China, introduced by Wilson during his first expedition for Messrs Veitch, and was described by him, as a species, from a plant growing in Veitch’s nursery, raised from his seed-number 1087 (corresponding to specimen W.2187). It also occurs in W. Szechwan, but some of Wilson’s collections there, referred to the var. veitchii in Plantae Wilsonianae, seem to be less distinct from typical P. davurica.
Cultivated plants have flowers about 1⁄4 in. wide, saucer-shaped when they first open; they are produced over a long period from later spring but never in great quantity, at least in the form available in commerce.
Note. P. davurica Nestl. (or P. fruticosa var. davurica (Nestl.) Ser.) is the name that was accepted by all botanists for the species treated here, until Handel-Mazzetti pointed out, in 1940, that Nestler had described the flowers (from an herbarium specimen) as yellow, while in P. davurica as generally understood they are white. He adopted for this species the name P. glabra Lodd. It is a frequent source of difficulty in this group that the petals, whether originally yellow or white, usually turn eventually in herbarium specimens to a dingy yellowish colour. Nestler’s description, apart from the discrepancy over flower-colour, agrees perfectly well with the white-flowered species and his name is therefore retained here. It was published in the first half of 1816. The synonymous name P. glabrata Schlecht., also rejected by Handel-Mazzetti, was published some time in the same year, not in 1813 as stated in the Index Kewensis. It may be added that Maximowicz accepted plants with pale yellow flowers as part of the normal variation of the species.
P. × sulphurascens Hand.-Mazz. – This putative hybrid was described by Handel-Mazzetti from a specimen he himself collected in Yunnan S.E. of Chungtien in 1914. It had flowers of a very pale sulphur colour, more campanulate than in P. arbuscula but less so than in the form of P. davurica growing nearby. He took it to be a hybrid between the two.
P. × vilmoriniana (Komar.) Konken P .fruticosa var. vilmoriniana Komar. – A supposed hybrid between P. arbuscula and P. davurica raised by Vilmorin from seeds received from Szechwan, China, in 1905. For a description, see the section on garden varieties. The cultivated plant, which is almost certainly authentic, is hexaploid and, except in flower-colour, resembles P. arbuscula var. albicans.