Guyonia

Annual herbs; stems creeping, rooting at nodes, branches erect, 4-angled. Leaves decussate, petiolate, +/- ovate, membranous, crenulate, sparsely setose above and on nerves beneath; nerves 3-5, parallel-convergent. Flowers (4)5(-7)-merous, terminal or axillary, solitary or 2 or 3 together subtended, but not enveloped, by a caducous dentate-ciliate bract. Calyx: tube/receptacle ovoid; lobes linear-triangular, persistent, without intersepalar appendages. Petals obovate, delicate, pale pink. Stamens equal to slightly unequal; anthers ovoid to oblong-ellipsoid; connective produced below anther, with 2 inconspicuous tubercular anterior protuberances at junction with filament. Ovary adherent to calyx tube in lower half, ovoid, glabrous; style sigmoid; stigma capitate. Fruit a valvate capsule within membranous calyx which tends to rupture irregularly. Seeds relatively large and few, attenuate towards funicular end, upper half rounded, tuberculate or papillose.