Ammannia elata A.Fern.

Aquatic glabrous plant with stout prostrate stem, 4–8 mm. wide (dry), ± 1–1.2 m. long, profusely rooting at the nodes; stem pale, angled; adventitious roots ±10 cm. long.. Leaves narrowly triangular-lanceolate, 2–3.5(–6) cm. long, 0.6–1 cm. wide, narrowly acute at the apex, truncate to slightly rounded auriculate-cordate at the base; lateral venation ± obscure; petiole ± obsolete or scarcely 1 mm. long.. Cymes numerous, up to about 1.2 cm. wide in fruit, 7–15(–20 or probably more)-flowered; peduncle 3–5 mm. long; secondary branches ± 2 mm. long; pedicels 1–2 mm. long; bracteoles filiform, minute.. Calyx-tube obconic-angular, ± 1(–1.75) mm. long, becoming broadly cupular in fruit, up to 1.5 mm. long, ± 3 mm. wide; lobes 4, broadly triangular, 0.8 mm. tall, ± 2 mm. wide; appendages minute, evident in bud.. Petals 4, white (pale lilac in dried material), rounded-obovate, 1.2–1.5 mm. long, 1–1.2 mm. wide, very fugitive.. Stamens 4–8.. Style and capitate stigma together 0.5 mm. long.. Capsule dark red, globose, 2–3 mm. wide, bursting irregularly.. Seeds pale brown, concave-convex, 0.5 mm. long.. Fig. 12/9–12, p. 39.