Description
Pistia – Shell Flower – Water Lettuce –
There is a sole species of an evergreen, floating aquatic perennial, in this genus. It is distributed word wide in the tropics and subtropics. It is grown for its ribbed, rosettes of wedge shaped leaves, resembling blue green lettuce heads, and for the exquisite coloring of its fine, feathery roots, which turn from white to purple and finally black, the roots emerging from the base of the rosette extract nutrients directly from the water. Although regarded as a noxious weed in some areas, where its radiating stolons cover the surface of the water, it is an excellent ornamental plant for a sunny, temperate pool.
Grow as a floating aquatic in full sun with some midday shade in warm subtropical to tropical conditions in a pond or a slow moving water.
Prone to aphids,
P. stratiotes – This evergreen, floating aquatic perennial from the tropics and subtropics grows 4″ tall with an indefinite spread. It multiplies rapidly. It has spreading or semi upright, wedge shaped, glaucous leaves, to 8″ long, fluted above and ribbed beneath, borne in floating rosettes. It bears inconspicuous, tubular flowers in leaf like spathes in the leaf axils, irregularly throughout the year. Fish will feed on its roots.
Zones 9-11
