Three New Species of Hypoestes (Acanthaceae) from Southeastern Madagascar

Abstract

Hypoestes Sol. ex R. Br. (Acanthaceae: Justicieae) is most diverse in Madagascar, with over 90 species, and no modern taxonomic treatment has been done. Here, we describe three new species from south­eastern Madagascar. Hypoestes dauphinensis S. Lowry & Appleq., as herein circumscribed, is highly vari­able; it has long-petiolate leaves, pubescent involucres fused for up to 25% of their length, and small flowers with long, reflexed lips. Hypoestes linearifolia S. Lowry & Appleq. is remarkable for its very long, narrow leaves, ca. 11–17 × 0.9–1.7 cm. Both of those are from the Anosy Region. Hypoestes phillipsonii S. Lowry, I. Darbysh. & Appleq., from the vicinity of Ranomafana National Park, is among a group of species with short, narrow leaves; it also belongs to a group of species with flowers resembling those of H. forskaolii (Vahl) R. Br. and is distinguished from the most similar species of that group, H. flavovirens Benoist, by features includ­ing greater indument on some organs, paniculate inflo­rescences, and involucral bracts fused for more of their length and bearing few glandular trichomes.