Oldenlandia

Annual or perennial herbs, rarely subshrubs; stems erect or prostrate, simple or branched. Leaves attached to stipular sheath at base; stipules with 1-several fimbriae. Flowers heterostylous or isostylous; usually in terminal clusters. Calyx 4-partite, equal, narrowly to broadly triangular. Corolla 4-lobed, white; usually with short tube, bearded in throat. Stamens 4, included or exserted; with glabrous or rarely papillose filaments; anthers dorsifixed, sometimes subsessile. Ovary 2-locular, with many ovules in each locule on shortly stalked placentas; style included or exserted, glabrous or minutely hairy; stigma lobes linear to subglobose. Fruit a subglobose to oblong capsule, usually with loculicidal dehiscence. Seeds usually many, subglobose or angled, becoming slimy when moistened; testa cells smooth to distinctly punctate, granular or tuberculate. x = 9 (11) (aneuploids, high polyploidy).