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. verticillatum – Myriad Leaf – This aquatic perennial from Europe, Asia and North America has an indefinite spread. From unbranched stems to 3′ feet long it carries linear, pinnatifid, tightly packed, bright green submerged leaves, to 1 ½” long, are arranged in whorls of 4-6, with 8-16 pairs of opposite segments. Emergent smaller leaves are pinnatifid and comb-like, to 1″ long. In summer it bears bright yellowish flowers in a spike, to 6″ tall, just above the water surface.
Zones 3-11
