Northern Prairie Wildlife Research Center
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.).
Previous Species -- Myriophyllum pinnatum (Walt.)
Return to Family -- Haloragaceae - The Water