Chamaegigas

Small, perennial, aquatic herbs; main stem a compressed rhizome. Leaves possibly heteromorphic; basal leaves submerged, in dense tuft or rosette, bifurcate through lateral fusion of basal part of 2 leaves, each lobe linear-subulate, falcate, fleshy, glabrous; upper floating leaves, or bracts, in 2 decussate, adjacent, unequal pairs, obovate or lanceolate, obtuse, glandular-punctate, subtended by filiform stalk arising from single bud in axil of double basal leaf. Flowers 1 or 2(3), exserted above floating leaves on short pedicels, recurving in fruit. Calyx 5-lobed, cup-shaped; lobes triangular, obtuse, subequal, shorter than tube. Corolla bilabiate; tube +/- equal to or shorter than upper lip, funnel-shaped with glandular hairs inside; upper lip hooded with upper edge recurved, emarginate, exterior in bud; lower lip much longer, 3-lobed, central lobe larger and apex square, lateral lobes spreading, smaller. Stamens 4, didynamous, arising in corolla throat but +/- decurrent; posterior pair short, erect, arched above, included in hood, with anthers cohering; anterior pair with filaments geniculate and expanded at base, there covered with stalked glands, filaments free above, bent up and inwards, forming arch; anthers cohering close to posterior pair; anthers bithecate, thecae divergent; staminodes 0. Nectary 3-lobed, below ovary, on anterior side. Ovary bilocular, ovoid; ovules +/- 20 per locule on swollen axile placenta; style appressed to dorsal side of tube and upper lip, arched downwards so stigma exserted in front of stamens; stigma with 2 broad, obtuse, papillate lobes. Fruit a bilocular capsule, ovoid when immature. Seeds elongate-elliptic, 12-sided, faces ribbed; endosperm not alveolate.