(Adams) Komarov
Description
Halerpestes sarmentosa is a widely distributed stoloniferous perennial of saline and moist open ground across temperate Eurasia, documented from Russia, China, India, Mongolia, Kazakhstan, Afghanistan, Tajikistan, Pakistan, Kyrgyzstan, Nepal and Uzbekistan, with disjunct and partly introduced records in the Americas (the more than 2170 GBIF occurrences include adventive populations). It favours damp meadows, lake and stream margins, marshy depressions and alkaline flats, typically from the lowlands to around 4500 m. The plant photographed at Bersay (Sikkim, West Bengal) at about 2800 m in April reflects its occurrence in moist montane grassland during early flowering.
The species is a low, mat-forming herb spreading by slender rooting stolons (sarmentose runners), from which arise long-petiolate basal leaves. The leaf blades are simple, ovate to reniform or somewhat three-lobed, with crenate margins and a cordate to truncate base, rather thick and slightly fleshy. The leafless scapes bear one to a few small flowers; the five spreading sepals subtend five narrow, yellow, nectariferous petals each with a basal scale. Stamens and carpels are numerous, the latter densely aggregated on an elongating receptacle and maturing into a globose to ovoid head of small, flattened, faintly ribbed achenes with a short straight beak.
Halerpestes was segregated from Ranunculus on the basis of its stoloniferous halophytic habit, leathery entire leaves and distinctive achene structure, the genus being centred on the steppe and saline wetlands of Central Asia. The taxon is also catalogued under the orthographic variant Halerpestes sarmentosus. Ecologically it is a salt-tolerant wetland colonist of grazed and disturbed shores; its broad range and tolerance of human-modified habitats render it of least concern, and its near-cosmopolitan spread illustrates the biogeographic links between Eurasian and American cold-temperate floras.
Author: (Adams) Komarov · Sources: POWO (Kew), GBIF, Flora of China, Flora of Bhutan, Annotated Checklist of the Flowering Plants of Nepal, Tamura's monograph of Ranunculaceae