Rediscovery and amended description of Strobilanthes humilis (Acanthaceae)

Abstract

Strobilanthes Blume consists of approximately 350 species, chiefly distributed in the tropical and sub-tropical parts of Asia but extending to the Pacific islands. Approximately 150 species of Strobilanthes are reported from India and, among them, around 70 species are restricted to South India. In the course of a floristic survey in the Megamalai Hills of Tamilnadu in 2016–2017, we collected a remarkable specimen of Strobilanthes, which was characterized by having viscous uninterrupted spikes with a subventricose corolla. Since it has spicate inflorescences, 5-partite calyces, two fertile stamens, and densely hygroscopic-pubescent seeds, the material belongs to the S. kunthiana group. After a critical examination of relevant literature and herbarium materials it was found that the specimen matches the type of S. humilis, hence our collections are the first verified collection after its type collections in 1836.