5. Ottelia , Syn. Pl. 1: 400 (1805).
Taxon Description
Perennial submerged herbs. Roots adventitious. Stems usually corm-like. Leaves submerged or emergent, usually broadly oval, oblong-elliptic, suborbicular, cordate or sometimes lanceolate, base varying greatly in shape and size, membranous. Stipules absent. Petiole length varies extensively. Spathe tubular, bifid, normally with 2–6 wavy wings. Flowers arise from spathe, which encloses ovary, actinomorphic, bisexual, solitary, sessile. Sepals persistent, linear to narrowly oblong. Petals white, obovate. Stamens 6; filaments glandular hairy; anthers narrowly oblong. Ovary oblong to narrowly ellipsoid, to tapered above into short stout beak; styles deeply 2-lobed. Fruit oblong, beak crowned by persistent calyx opening irregularly by top. Seeds fusiform, densely hairy.
Taxon Statistics
Worldwide 19 species, in tropical to temperate areas. One species in Nepal.
1. Ottelia alismoides (L.) Pers., Syn. Pl. 1: 400 (1805).
Stratiotes alismoides L., Sp. Pl.: 535 (1753); Ottelia lanceolata (Gagnep.) Dandy
Perennial submerged herbs, 21–28 cm. Stems usually corm-like. Roots adventitious. Leaves submerged or emergent, basal varying greatly in shape and size, usually broadly oval, oblong-elliptic, suborbicular, cordate, or sometimes lanceolate, 15–21 X 2–6 cm, membranous. Petiole length varies extensively, up to ca. 18 cm. Spathe tubular, bifid, ca. 3 cm, normally with 2 wavy longitudinal wings. Flowers arise from spathe, which encloses ovary, actinomorphic, solitary, sessile. Sepals persistent, linear to narrowly oblong. Petals white, obovate. Stamens 6; filaments glandular hairy; anthers narrowly oblong, 3–4 mm. Ovary oblong to narrowly ellipsoid, ca. 4 cm, tapered above into short stout beak; styles deeply 2-lobed. Fruit oblong, ca. 1.5 X 0.8–1.5 cm, with beak crowned by persistent calyx opening irregularly by top. Seeds fusiform, 1–2 mm, densely hairy.
Distribution: Nepal, Assam-Burma, S Asia, E Asia, SE Asia; and Australasia.
Altitudinal range: 100–400 m.
Ecology: Still or running water.
Flowering: April-August. Fruiting: September-October.
Leaves are medicinal (Sumithira et al., 2021).