USGS - science for a changing world

Northern Prairie Wildlife Research Center

  Home About NPWRC Our Science Staff Employment Contacts Common Questions About the Site

Aquatic and Wetland Vascular Plants of the Northern Great Plains

29. Haloragaceae, the Water Milfoil Family

1. Myriophyllum L. -- Water milfoil

4. Myriophyllum verticillatum L.

Quite similar to M. exalbescens, often more robust with stems 5-25 dm long. Leaves in whorls of 4-5, with 9-13 filiform segments along each side of the midrib, 1-4.5 cm long; lower and middle nodes mostly less than 1 cm apart; winter buds present fall to early spring, clavate, yellow-green. Flowering spikes 4-12 cm long, the floral bracts much smaller than the leaves, pectinate, mostly exceeding the flowers; bracteoles minute or absent, palmately 7-lobed. Flowers perfect or the lower female and the upper male; petals reduced in female flowers, otherwise spoon-shaped, obtuse, to ca. 2.5 mm long; stamens 8. Fruits brownish, subglobose, 2-3 mm long, the mericarps rounded on the back, smooth or somewhat roughened. Jun--Sep. In much the same habitats as M. exalbescens, but restricted to fresh water; uncommon, from scattered locations in ND, e SD and nc NE; (Circumboreal, in N.Amer. s to MA, NY, IN, ne TX, NE, UT and B.C.).
GIF- Distribution Map

Map key

Previous Species -- Myriophyllum pinnatum (Walt.) B.S.P.
Return to Family -- Haloragaceae - The Water Milfoil Family

Accessibility FOIA Privacy Policies and Notices

Take Pride in America logo logo U.S. Department of the Interior | U.S. Geological Survey
Page Contact Information: Webmaster
Page Last Modified: Saturday, 02-Feb-2013 06:44:51 EST
Sioux Falls, SD [sdww54]