Monotheciinae

Manzitto-Tripp, Erin A., Darbyshire, Iain, Daniel, Lucinda A. McDade Thomas F. & Kiel, Carrie A., 2022, Revised classification of Acanthaceae and worldwide dichotomous keys, TAXON 71 (1), pp. 103-153 : 141

Monotheciinae Lindau in Bot Jahrb. Syst. 18: 56. 1893, emend. Kiel, I.Darbysh. & T.F.Daniel – Type: Monothecium Hochst.

Perennial herbs, shrubs or small trees with cystoliths; leaves opposite, isophyllous to strongly anisophyllous; inflorescences varying from terminal to axillary or sometimes ramiflorous or cauliflorous, inflorescence form highly variable, ranging from open dichasia to spicate or paniculate thyrses, to contracted few-branched dichasia or flowers solitary, flowers subtended by paired bracteoles, bracts and/or bracteoles inconspicuous or conspicuous; corollas variable in size, shape and color, bilabiate, upper lip often hooded, rugula absent, lower lip often with 2 raised ridges and a central furrow running into the throat; androecium of 2 stamens and no staminodes (except in Ptyssiglottis staminodifera where 2 staminodes present), anthers bithecous or ( Monothecium only) monothecous, thecae of a pair subequally or unequally inserted on filament, parallel or slightly oblique, with or more commonly without basal appendages; stigma 2-lobed; capsule (where known) clavate, 4-seeded, retinacula present and not separating from inner capsule wall at maturity; seeds (where known) lenticular, surfaces variously ornamented, often tuberculate, trichomes absent; pollen most frequently prolate and 3-colporate, 6-pseudocolpate but with variation up to 4- or 5-colporate, 8- or 10-pseudocolpate, and also spheroidal pantoporate.

Below, we validate names for two genera from Madagascar that have been applied in the literature and in various databases for several decades now but were not validly published at the time of original description. The status of these genera within the classification of Acanthaceae remains to be further researched. These validations thus serve to facilitate future discussion. Small diagnostic descriptions are provided to aid identification of these two poorly known taxa; full descriptions are available in the original publications ( Benoist, 1962).