Erect monoecious obscurely papillose annual aquatic herb up to 60 cm.. Roots long, white.. Orthotropic stem green at base, reddish above. Plagiotropic shoots up to 10 cm. long, the older ones subtending secondary orthotropic shoots.. Cataphylls lanceolate, 1 mm. long, pinkish. Cataphyllary stipules obliquely ovate-lanceolate, auriculate on one side at the base, 1 mm. long, pinkish with a white hyaline margin.. Leaves of the plagiotropic shoots distichous; petioles 0.3–0.5 mm. long; blades narrowly elliptic, 5 mm. long, 1.5–2 mm. wide, obtuse at the apex, cuneate or rounded at the base, chartaceous, lateral nerves 4–5 pairs, not clearly visible above, visible beneath, bright green above, glaucous beneath, with a red margin.. Stipules linear-lanceolate, 0.5–1 mm. long, whitish with a pink median stripe.. Male flowers up to 4 per axil, in the proximal half or two-thirds of the plagiotropic shoots, ♀ solitary in the distal half or third.. Male flowers: bracts resembling the stipules; pedicels 1 mm. long; sepals 5, obovate-suborbicular, 0.8 mm. long, 0.7 mm. wide, obtuse, rose-coloured with a reddish midrib; disc-glands 5, free, flattened, papillose; stamens 2, the filaments united into a column 0.3 mm. high, anthers ± sessile, reniform, 0.2 mm. across, horizontally dehiscent, yellow.. Female flowers: pedicels 1 mm. long, extending to 1.5 mm. in fruit; sepals 5, ovate, 1 mm. long, 0.8 mm. wide, obtuse, rose-coloured with a broad reddish-purple median band, persistent; disc flat, thin, 5-lobed, the lobes alternating with the sepals; ovary sessile, depressed-subglobose, 0.5 mm. diameter, smooth, reddish purple; styles 0.2 mm. long, ± free, adpressed, bifid, rose-coloured, stigmas subcapitate.. Fruit oblate-spheroidal, 1.5 mm. long, 2 mm. diameter, smooth, purple.. Seeds 1 mm. long, with 8–9 longitudinal ridges on the dorsal facet, and 6–7 shallow concentric ridges on each ventral facet and with numerous transverse striae between the ridges, light brown, paler on the ridges.. Fig. 3/5, p. 22.
Home