Howelliella Rothm., Leafl. West. Bot. 7(5): 115 (1954). Annual herbs; stems homomorphic, erect or ascending, the branches not cirrhous. Leaves more or less homomorphic, simple, ovate to oblong-elliptic, entire, pinnately veined, the midrib terminating in conspicuous, swollen gland, the basal leaves petiolate, opposite, the petioles not cirrhous, the upper leaves subsessile, alternate. Flowers zygomorphic, pedicellate, in terminal leafy racemes. Floral leaves often subtending additional branches, the branches not cirrhous. Pedicels not cirrhous. Calyx deeply divided; lobes very unequal, entire, imbricate, the adaxial lobe greatly exceeding abaxial 4 lobes, exceeding corolla-tube. Corolla with tube cylindrical, produced abaxially at base into short, broad spur; limb bilabiate, the lips unequal, widely divergent, the adaxial lip reflexed, the abaxial lip erecto-patent to somewhat reflexed, exceeding adaxial lip, the basa1 palate poorly developed, not 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, with rudimentary anther. Style simple, obliquely inserted; stigma linear or scarcely capitate, entire, positioned between anthers of fertile stamens. Capsule somewhat obliquely ovoid, the walls papyraceous, the septum more or less erect, straight; loculi somewhat unequal, the abaxial loculus broader than adaxial, many- seeded, each loculus dehiscing by irregular ruptures forming 1 pore, opening more or less from apex to base. Seeds oblong-ovoid to subconical, somewhat dorsi-ventrally asymmetrical, irreg- ularly reticulate-alveolate or partially cristate; hilum subbasal on dorsal face; ridges sinuate, variably anastomosed, those on dorsal face somewhat smaller than those on ventral face; periclinal wall of testa-cells sometimes with marginal papilla; epicuticular waxes apparently absent. By Sutton (1988)