Acanthorrhinum Rothm. Acanthorrhinum Rothm., Feddes Repert. 52: 31 (1943). Dwarf shrubs; stems homomorphic, erect, the branches not cirrhous. Leaves homomorphic, simple, entire, pinnately-veined, sessile, alternate. Flowers zygomorphic, pedicellate, in termi- nal, bracteate racemes. Bracts minute, not resembling foliage leaves, not subtending additional axillary shoots. Pedicels not cirrhous. Calyx deeply divided, the lobes entire, valvate, not accrescent, subequal, shorter than corolla-tube. Corolla with tube cylindrical, ecalcarate, inconspicuously gibbous abaxially at base; limb bilabiate, the lips subequal, the adaxial lip erecto-patent to patent, scarcely exceeding abaxial, the abaxial lip spreading, with prominent palate occluding mouth of tube; lobes entire. Fertile stamens 4, didynamous, included, the adjacent pairs of anthers marginally coherent, the connective not dilated above anther; staminode minute. Style simple, erect; stigma linear, entire, positioned between anthers of fertile stamens. Capsule subglobose, emarginate, glabrous, the walls somewhat coriaceous, the septum erect, straight; loculi subequal, usually many-seeded, dehiscing more or less simul- taneously, each loculus dehiscing by solitary pore with 4-7 more or less equal valves, from apex to middle of wall. Seeds oblong-ovoid, bilaterally symmetrical with conspicuous dorsi-ventral asymmetry; hilum subbasal on dorsal face; dorsal face cristate with c. 5 irregular, longitudinal ridges, the ventral face irregularly reticulate-alveolate to lacunose with encircling, emarginate, wing-like ridge usually branched and anastomosed with inner ridges or with some isolated tubercles; periclinal wall of testa-cells tabular or convex, sometimes with median papilla; epicuticular waxes present, granulate. Modified from Sutton (1988)