Description
Myriophyllum – Milfoil –
There are about 45 species of submerged or marginal aquatic annuals and perennials in this genus. They occur in wet ground, ponds, and streams with representatives worldwide. The foliage is highly decorative, with long, submerged, delicate stems and alternate, opposite, or whorled leaves. The submerged leaves are linear to oblong or rounded, and pinnatifid, with fine, hair like segments, the emergent leaves are smooth edged or toothed, and lance shaped to ovate or linear. They provide refuge from predators, as well as oxygenating the water.
Grow in containers of loamy soil in full sun although tolerant of part shade, at a depth of 6″ for M. aquaticum 18″ for M. hippuroide and 3′ feet for M. verticillatum. Top growth may be damaged by frost, but should reemerge below the surface in spring.
Prone to be eaten by fish, and algae may cover the plants.
M. hippuroides – Western Milfoil – This aquatic perennial from Southwestern USA has an indefinite spread. From thin stems, to 24″ long, it carries lance shaped to ovate, pinnatifid, yellow-green submerged leaves, to 3/4″ long, with up to 25 segments. Linear to lance shaped, finely divided, olive-green to red emergent leaves, 2″ long are held in whorls of 4-6, are usually upward pointing. Bears minute white flowers from the axils of emergent leaves.
Zones 9-11
