Berberis setifolia (Berberidaceae), a new rank for Berberis macrosepala var. setifolia

A new rank and combination, Berberis setifolia (Ahrendt) Bharali, B.Hajong & Harber is proposed for B. macrosepala var. setifolia Ahrendt, based on a morphological examination of herbarium specimens from Me La, NE Bhutan and Se La, Arunachal Pradesh, India and living plants from Se La. The treatment of B. macrosepala Hook.f. & Thomson by Ahrendt in his two monographic treatments of Berberis (i.e. Ahrendt 1941, 1961), is shown to not fully reflect the protologue, which describes the taxon as not just one-flowered, but also fascicled. Some specimens that Ahrendt cites, including those of the three varieties of B. macrosepala he proposed, are determined to belong to other species, some of which are unrecognised. Herbarium specimens of Ahrendt’s B. macrosepala var. setifolia from Bhutan are shown to be the same as those of a hitherto unidentified species from Arunachal Pradesh. A detailed taxonomic description, notes on habitat and ecology, and colour photographs are provided for B. setifolia.