pickerelweed

pickerelweed common name for the Pontederiaceae, a family of chiefly tropical perennial aquatic herbs found in freshwater. The pickerelweeds (genus Pontederia ) range north into temperate regions, including most of the E United States and Canada. The water hyacinth ( Eichhornia crassipes ), a native of tropical America, has spread widely and is so prolific that it has clogged many waterways in the S United States and in other areas, including Java, Australia, and the Great Lakes region of E Africa. It is sometimes cultivated in tanks and ponds for its ornamental foliage and blue-violet flowers. The pickerelweed family is classified in the division Magnoliophyta , class Liliopsida, order Liliales.

Pontederiaceae (order Liliales) A family of monocotyledonous (see MONOCOTYLEDON) freshwater, aquatic plants. The leaves have sheathing bases, often petiolate. The flowers are blue, lilac, yellow or white, with 6 perianth segments, often borne in a showy inflorescence enclosed by a spathe-like sheath. The fruit is a capsule or nutlet. The free-floating water hyacinth (Eichhornia crassipes) is probably the world's most serious aquatic weed. Other species are grown as aquatic ornamentals. There are 7 genera, comprising 29 species, occurring in the tropics and subtropics, especially America.