Floating aquatic herb ± 30–50 cm. tall with erect rosulate leaves and a dense tuft of plumose roots; reproducing vegetatively by means of stolons which give rise to new plants that readily separate; broken pieces of plant also form new plants rapidly. Leaves radical, erect, emerging from the water, rosulate; blades rhomboid or ovate, obtuse at the apex, cuneate to shallowly cordate, glabrous, very densely nerved, 5–25 cm. long and broad; petioles spongy, very much swollen at or below the middle, particularly in young plants, up to 30 cm. long; stipules 2–15 cm. long, with a blade-like portion above. Flowering stems with small apical leaf ± 2 cm. long and broad, its sheath large, ± 4 cm. long and 1.5 cm. wide, enclosing the spathe. Inflorescence with long peduncle, spicate, puberulous, of ± 3–35 flowers, 4–15 cm. long, bending over after fertilization. Perianth lilac or white, the upper lobe with a deep violet blotch containing a yellow spot; outer lobes narrowly elliptic; inner broadly elliptic, ± 3 cm. long; perianth-tube pubescent, 1.5–1.8 cm. long. Stamens unequal (see note); filaments pubescent. Capsule ±1.5 cm. long. Seeds winged, 1.2 mm. long and 0.5 mm. wide.
Plant usually floating. Leaves aerial, arising in tufts, up to 8 x 8 cm, rhombic to suborbicular; petiole variable in length, the shorter ones much inflated in the lower half, and all consisting largely of spongy aerenchyma. Spike c. 15 cm, with 8-12 flowers 5-7 cm across. Anthers yellow, variably tinged with blue. Stigma capitate, coarsely papillose.
HAB. Slowly flowing rivers, lakes formed by dams and small ponds; 0–1700 m.
Kenya Nairobi, Aug. 1958, Agric. Dept, in E.A.H. 11830! (sterile) & Nairobi City Park, 5 May 1957, Duncan 1236!
Tanzania R. Sigi near the Amboni Sisal Estate, from estuary for several kilometres upstream, Mar. 1958, C. G. van Someren in E.A.H. 11881! Also reported from R. Pangani, and Soni in W. Usambara Mts.
Tanzania W. Usambara Mts, 6.5 km. NE. of Lushoto, Mkuzi, 11 June 1953, Drummond & Hemsley 2887!
in A.DC, Mon. Phan. 4: 527 (1883); Schwartz in E.J. 61, Beibl. 139: 34 (1927); Perrier, Cat. Pl. Madag.: 10 (1934); Täckholm & Drar, Fl. Egypt 2: 441–8 (1950); Backer in Fl. Malesiana, ser. 1, 4: 259, figs. 2 & 3 (1951); Jonker-Verhoef in Fl. Suriname 1: 85 (1953); Wild, Common Rhodesian Weeds, fig. 10 (1955), as “Eichornea”, & in Kirkia 2: 9, frontispiece (1961); Ivens, E. Afr. Weeds: 3, fig. 3 (1967).