PLECTRANTHUS, in botany: A genus of the gymnospermia order, belonging to the didynamia class of plants; and in the natural method ranking under the 42d order, Verticillatae. The calyx is monophyllous, short, and bilabiate; the upper lip of which is large, oval, and bent upwards; the inferior lip is quadrifid, and divided into two laciniæ: the corolla is monopetalous, ringent, and turned back; the labia look different ways, and from the base of the tube there is a nectarium like a spur: the filaments are in a declining situation, with simple antheræ: the stylus filiform; the stigma bifid. It has four seeds covered only by the calyx. There are two species, viz. 1. The fruticosus, a native of the Cape of Good Hope; 2. Punctatus, a native of Africa. The first flowers from June to September, the latter from January to May.