Monochoria vaginalis (Burm.f.) C.Presl

Family Description

Annual or perennial, aquatic or marsh herbs. Stems short or thickly rhizomatous. Leaves commonly in basal rosette; petiole margins developed upwards into stipules. Infl. terminal on sacpe, commonly spike-like or condensed and sub-umbellate, subtended by 2 ± tubular spathes, lowermost often with leaf-like blade. Flowers short-lived, zygomorphic to actinomorphic, tepals 6, ± free or sometimes fused into tube below; bisexual, sometimes tristylous. Stamens usually 6, sometimes 1 or 3, anthers all similar or 1 large and 5 small. Ovary superior, (1-)3-loculed; ovules usually axile; style elongate; stigma captitate to trifid. Fruit a 3-loculed capsule, surrounded by remains of flower.

Genus Description

Annual or perennial, commonly emergent aquatics. Stemless or rhizomatous. Leaves basal, usually with petiole and blade. Infl. racemose or sub-umbellate, rarely paniculate, subtended by sheathing spathes; lower spathes usually with leaf-like blade so infl. often appearing lateral. Flowers actinomorphic, tepals 6, free. Stamens 6; anthers all alike or one larger than others; filaments equal, one usually with tooth near apex.

Species description

Usually annual. Leaves in basal rosette or on shortly decumbent stem, blades lanceolate (occasionally very narrowly) to ovate, acuminate, usually shallowly to deeply cordate, sometimes truncate, 1.5-5(-8) x 1-3.8(-7)cm. Petioles usually exceeding scape, margins of petioles and stipules membranous, sometimes purplish. Stipules 0.5-2cm. Scape 3-17(-41)cm. Infl. sub-umbellate to racemose, erect at first, strongly deflexed in fruit; upper spathe membranous, shorter than infl., lower spathe leaf-like, conspicuously exceeding infl. Flowers pedicellate; tepals 6, blue, persistent, 7-12mm. Anthers 5 small (1-1.2mm) on simple filaments, 1 large (2.3-2.5mm) on filament with sharp, ascending 3-lobed. Capsule ellipsoid, 2-2.7 x 1.5-1.7mm; style 3-3.5mm; stigma shortly 3-lobed. Capsule ellipsoid, 6-10 x 4-6mm. Seeds oblong, c.0.8 x 0.4mm, longitudinally ribbed, pale brown, tip darker.