3. Caldesia, Fl. Ital. (Parlatore) 3(2): 598 (1860).
Taxon Description
Annual or perennial herbs, rhizomatous. Roots fibrous. Leaves petiolate, aerial, floating or submerged, with distinct veins parallel with margins and converging towards apex. Scape erect. Inflorescence paniculate, much branched, branches whorled, bracts lanceolate to slightly triangular. Flowers pedicellate, bracteate, bisexual, verticillate. Sepals 3, persistent. Petals 3, white. Stamens usually 6, anthers basifixed. Carpels free, numerous, arranged in a single whorl, style persistent. Fruit drupaceous achenes, with woody endocarp. Seeds oblong to obovoid.
Taxon Statistics
Four species world-wide. One species in Nepal.
1. Caldesia parnassifolia (L.) Parl., Fl. Ital. (Parlatore) 3(2): 599 (1860).
Alisma parnassifolium L., Syst. Nat., ed. 12. 3: 230 (1768); Alisma reniforme D. Don; Caldesia reniformis (D. Don) Makino.
Herbs 35–40 cm, aquatic. Rhizomes creeping. Leaves in basal rosette, petiole 6–14 cm, base sheathing, leaf blade elliptic to reniform, (3–)4–8 X (2.5–)4–8 cm, base cordate to deeply cordate, apex obtuse to rounded, veins 10–14, parallel and converging towards apex and connected by transverse veins. Inflorescence 14–35 cm, bracts lanceolate, 0.2–1.3 cm. Pedicels whorled, 2–4.5 cm, enlarging in fruit. Sepals green, ovate to lanceolate, 3.5–5 X 2–3 mm, enlarging in fruit. Petals white with a yellow claw, obovate to suborbicular, 5 X 3.5–4 mm, margin slightly dentate, irregular, very delicate. Stamens 6, arranged in a single whorl, Filaments 2–2.5 mm, glabrous, Anthers yellow, oblong, ca. 1 mm. Carpels 5–15, yellowish, obovate, laterally compressed, ca. 1 mm, enlarging in fruit. Achenes obovoid, 3–9 X 2–5 mm, apex acute to acuminate, with erect apical beak. Seeds pale brown, ca. 2 mm.
Distribution: Nepal, W Himalaya, Assam-Burma, S Asia, E Asia, SE Asia, N Asia, SW Asia; Europe, Africa and Australasia
Altitudinal range: 100–650(–800) m.
Ecology: In lakes, ponds and marshes.
Flowering: May–October. Fruiting: May–October.
*Note: The description of the flowers and seeds adapted from the Flora of China, Flora of Thailand and Flora of Tropical East Africa.