Potentilla fruticosa var. arbuscula — Rosaceae

Potentilla fruticosa var. arbuscula

by GP Jürgens

(D.Don) Maxim.

Sikkim2003 189 P260
Sikkim Dzongri 4100m, August

Description

Potentilla fruticosa var. arbuscula is a shrubby cinquefoil of the high mountains of the Sino-Himalayan region, recorded from China, Nepal, Bhutan and Japan. GBIF treats the name as a synonym, with Potentilla fruticosa var. arbuscula (here cited following the source) regarded as the accepted designation for this entity; in modern treatments the shrubby cinquefoils are often placed in the segregate genus Dasiphora. It grows in alpine and subalpine scrub, open meadows, rocky slopes and stream-sides above and near the treeline, generally between about 3000 and 4500 m. The photographed plant comes from Dzongri in Sikkim at around 4100 m, flowering in August. With over 400 georeferenced records it is a well-documented high-montane shrub.

It forms a low, much-branched deciduous shrub, often spreading or cushion-like at the highest elevations, the bark shredding and the young shoots silky-hairy. The leaves are pinnate with usually five small, narrow, oblong leaflets that are green above and densely silvery-silky beneath, with revolute margins. The flowers are solitary or few in the leaf axils and at the branch tips; each has five green sepals alternating with epicalyx segments and five broad, rounded, golden-yellow petals exceeding the calyx. The numerous stamens surround a hairy receptacle bearing many free carpels, which ripen into a head of small hairy achenes.

The shrubby cinquefoil complex is taxonomically intricate and widely cultivated in horticulture; var. arbuscula is distinguished within it by its dense indumentum and Himalayan high-altitude form. Its abundant nectar-rich flowers attract a range of insect pollinators. As a common and broadly distributed alpine shrub it is of least conservation concern.

Author: (D.Don) Maxim. · Sources: POWO (Kew), GBIF, Flora of China, Flora of Bhutan, Soják's revisions of Potentilla and Dasiphora

Within the same family