Abstract
The small West Himalayan genus Decalepidanthus (Boraginaceae) is reviewed. Decalepidanthus was erroneously transferred to Pseudomertensia, although the former name antedates the latter by four years. Seven species of Decalepidanthus are accepted in this paper, D. echioides, D. elongatus, D. moltkioides, D. parviflorus, D. primuloides, D. racemosus and D. trollii. Two additional entities, D. flavescens and D. rosulatus are considered unresolved. A synopsis of the genus is provided, the necessary new combinations are made, and a dichotomous key and distribution maps to the accepted species are given. Lectotypes are designated for Lithospermum echioides, L. secundiflorum, Mertensia tibetica and M. nuristanica, and a neotype for Moltkia trollii. Mertensia lindelofioides and Pseudomertensia drummondii are excluded from Decalepidanthus and referred to the genus Lindelofia.