16. Dasiphora Rafinesque, Autik. Bot. 167. 1840.
Bush cinquefoil [Greek dasys, hairy, and phoros, bearing, alluding to villous hypanthium]
Barbara Ertter, James L. Reveal
Potentilla Linnaeus [unranked] Comocarpa Torrey & A. Gray; Potentilla sect. Comocarpa (Torrey & A. Gray) O. Stevens; Potentilla subg. Dasiphora (Rafinesque) Jepson; Potentilla sect. Fruticosae (Döll) Grenier & Godron; Potentilla sect. Rhopalostylae (Th. Wolf) Guşuleac
Shrubs, (0.2–)1–10(–16) dm; taprooted. Stems: number not recorded, prostrate to erect; bark reddish brown or grayish, ˂papery, shredding˃; lateral short shoots often present (bearing fascicles of leaves); unarmed; villous first year, then glabrous. Leaves deciduous, sometimes persistent, cauline, alternate, usually ± odd-pinnate to subpalmate (jointed beyond stipules and at distal leaflet node), rarely ternate; stipules persistent, proximally adnate to base of petiole, broadly lanceolate to ovate, margins entire; petiole present; blade ± ovate in outline, 0.5–2.6 cm, foliaceous, leaflets (3–)5(–7)[–9], ˂proximal pairs confluent on rachis˃, linear to narrowly elliptic or oblong, margins flat or revolute, entire, venation pinnate, surfaces glabrous or hairy. Inflorescences terminal and on lateral twigs, solitary flowers or 2–7(–30)-flowered, loosely cymose, glabrous or hairy; bracts present, ± leafy; bracteoles absent. Pedicels present, ˂straight˃. Flowers occasionally functionally unisexual (plants monoecious), [10–]15–30[–35] mm diam.; epicalyx bractlets 5; hypanthium patelliform to cupulate, 1–2 × 3.5–5 mm, villous; sepals 5, spreading, ovate [broadly elliptic]; petals 5, yellow [white], obovate to orbiculate, ˂longer than sepals˃; stamens 20 or 25(–30), shorter than petals, ˂filaments filiform, glabrous, theca solitary, horseshoe-shaped, rimming broad connective, dehiscing by continuous marginal slit˃; torus hemispheric; carpels 30–100, hirsute, styles sub-basal, ˂clavate˃; ovule 1. Fruits aggregated achenes, individually deciduous, 30–100, obliquely ovoid, 1.4–1.8(–2) mm, hirsute; hypanthium persistent; sepals persistent, erect; styles tardily deciduous, ˂jointed˃. x = 7.
Species ca. 12 (1 in the flora): North America, Eurasia.
Dasiphora comprises the shrubby cinquefoils, which are well known in the horticultural trade. All species occur in Asia; only D. fruticosa is also native to the flora area. Molecular analysis confirms the distinction of these species from Potentilla (T. Eriksson et al. 1998; M. Lundberg et al. 2009; C. Dobeš and J. Paule 2010), with morphological support provided by the shrubby habit, unique leaflet division, and anther structure (J. Soják 1989). Pentaphylloides Duhamel has been misapplied to this genus (for example, N. H. Holmgren 1997b); that name is based on Potentilla and accordingly not legitimate. Contrary to W. A. Weber and R. C. Wittmann (1996), Dasiphora is not nomenclaturally superfluous; P. A. Rydberg (1898) lectotypified it on P. fruticosa.
SELECTED REFERENCE Klackenberg, J. 1983. The holarctic complex Potentilla fruticosa. Nordic J. Bot. 3: 181–191.