Common Water Milfoil
Haloragaceae (Water Milfoil Family)
A free-floating, submerged, perennial aquatic herb.
Distinguishing Features - Leaves: in whorls, pinnately dissected, with 5 to 10 thread-like segments on each side of midrib; internodes between whorls about 1 cm long. Stem: simple to freely branched, elongate and flexuous, to 7.6 - 12.5 cm long. Turions: with reduced blackish leaves and shortened internodes often produced from lower nodes in late summer and fall, present through spring. Roots: white, thread-like; not always present Flowers: imperfect, borne in whorls on red spikes raised above the water's surface; male flowers above the female. Floral spikes: 2.5 - 10 cm long, clearly differentiated from underwater stems; floral bracts on spike much smaller than leaves, oblong to obovate in form. Petals: pink on male flower; absent on female, oblong-obovate, concave, 2 - 3 mm long. 8 stamens, yellow-green anthers conspicouous when flowering. 4-chambered pistil; ovary superior. Fruit: olive, almost round, 2 - 4 mm long, the segments rounded on back.
Native to boreal North America, south through most of the United States; in shallow to deep water inf lakes, ponds, marshes, ditches and slow streams.
Can be distinguished from other native milfoils by the leaves and flowers in whorls; bracts surrounding male flowers are entire and not longer than the flowers.
Return to Top of Page
| Ontario's North (West) Forest | Boreal Forests of the World | North (West) Forest Industry |
| World Links and Resources | "Forest Finder" Search Engine | Educational Resources |
| What's Happening | Contacts | Site Map |