A Revision of the North American Species of the Genus Anisacanthus

Abstract

Anisacanthus is a small genus of the Acanthaceae, which, because of the relatively few collections and the obscure specific characters, has been poorly understood. The present study was undertaken to correlate the morphological characters of the taxonomic entities of the genus as a whole, and to determine the relative value of the different characters in specific and varietal delimitation. Anisacanthus is one of several genera segregated from Justicia, having been described by Nees2 in the year 1842. He based it on Justicia qquadrifida Vahl,3 which in turn was founded on J. coccinea Cavanilles,4 a plant grown in the gardens of Madrid from stock brought from Mexico probably in the latter part of the eighteenth century. Vahl had changed the species name from coccinea to quadrifida because of the earlier J. coccinea Aublet. Under the name Justicia quadrifida Vahl, it was not infrequently cultivated in European gardens; and fortunately several authentic specimens from horticulture have been preserved in herbaria. Nees, however, soon changed the name of the type species to Anisacanthus virguclaris (Salisbury) Nees,5 and as such it was known until Standley revived the specific name quadrifidus.ff