Description from Flora of China
Bougueria Decaisne; Psyllium Miller.
Herbs, or rarely small shrubs or arborescent, annual, biennial, or perennial, acaulescent or infrequently stemmed, with a taproot, caudex, or only numerous fibrous roots. Leaves simple; petiole vaginate at base; leaf blade ovate, elliptic, oblong, lanceolate, linear, or subulate, margin entire, repand, erose, or toothed, rarely pinnately or palmately cleft. Inflorescences arising from rosette or leaf axil of stem, spikes, narrowly cylindric, capitate, or rarely 1-flowered. Corolla salverform or tubular, persistent; tube cylindric or constricted at throat, as long as or slightly longer than calyx; limb 4-parted. Stamens (1 or 2 or)4; anthers ovoid, suborbicular, ellipsoid, or oblong. Ovary 2-loculed or rarely 1-locular but sometimes with an apical third compartment, placentation axile or rarely basal, with 1 to numerous ovules per locule. Fruit a pyxis, rarely an indehiscent capsule or nutlet, with 1 to numerous seeds. Seeds peltately inserted; testa mucilaginous when wet; embryo straight; cotyledons parallel or vertical to ventral (hilum) side.
About 200 species: cosmopolitan; 22 species (three endemic, four introduced) in China.