Pontederia
(named after J. Pontedera, 1688-1757, once Professor of Botany at Padua). Pickerel Weed. SYN. Unisema. ORD. Pontederiaceae. A genus comprising seven or eight species of stove or hardy, aquatic plants, with stem-like or creeping rhizomes, all natives of North or South America. Flowers numerous, usually crowded at the sides of a rachis, scarcely pedicellate, the inflorescence terminal, compound, and densely cylindrical, rarely almost simple and racemiform; perianth funnel-shaped, with an incurved, slender or rarely abbreviated tube; stamens six. Radical leaves long-stalked, cauline ones short-stalked; all cordate, ovate, rotundate, or rarely lanceolate, with a long, loose sheath below the petiole. Stems (or branches) erect, simple, one-leaved. The best-known species is P. cordata; this is described as one of the handsomest hardy aquatic plants in cultivation. It is perfectly hardy, and should be planted in water from 6in. to 12in. in depth. Propagated by division, at almost any season.
P. angustifolia (narrow-leaved). A variety of P. cordata. P. azurea (azure). A synonym of Eichhornia crassipes. P. cordata (heart-shaped). fl. sky-blue, sometimes white, with a greenish spot on the inside of the upper lobe, in spikes, numerous, small. Summer and autumn. l. thick, on long stalks, lively green; petioles dilated, and sheathed at the base. h. 1 1/2ft. to 2ft. North America, 1579. See Fig. 250. (B. M. 1156.) P. angustifolia is a variety with narrow-lanceolate leaves, cordate at the base, and also with smaller, bright blue flowers. SYN. P. lanceolata (L. B. C. 613).
P. dilatata (extended). A synonym of Monochoria hastata. P. lanceolata (lance-shaped). A synonym of P. cordata angustifolia.