Whorled Water-milfoil - Myriophyllum verticillatum
Stems whitish, branched. Leaves 4-whorled, to 45 mm long, divided into 18 to 34 filiform segments. Bracts 3–8 mm long; longer than the fruits pectinate, 1 to 2 times as long as flowers. Female flowers with sepals <1 mm long; petals absent; bracts minute. Male flowers with small, yellowish petals; bracts dentate; stamens 8. Mericarps 2–3 mm long (Lesica 2012. Manual of Montana Vascular Plants. BRIT Press. Fort Worth, TX)
AK to NL south to CA, AZ, TX, IL, WV; Europe. Collected in Flathead, Lincoln, and Sweet Grass counties; reported for Sanders and several other counties (Lesica 2012. Manual of Montana Vascular Plants. BRIT Press. Fort Worth, TX).
Observations in Montana Natural Heritage Program Database
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- Additional ReferencesLegend: View Online Publication
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- Aiken, S.G. 1981. A Conspectus of Myriophyllum (Haloragaceae) in North America. Brittonia 33 (1): 57-69. A81AIK01PAUS.
- Britton, N. L. and A. B. Brown. 1913. An Illustrated Flora of the Northern United States, Canada, and the British Possessions. 2nd Edition in 3 Volumes. New York, NY: Charles Scribner's Sons. B13BRI01PAUS.
- Fassett, Norman C. 1940. A Manual of Aquatic Plants, 1st ed. New York: McGraw-Hill. B57FAS01PAUS.
- Fernald, M. L. 1950. Gray's manual of botany. Eighth edition. A handbook of the flowering plants and ferns of the central and northeastern United States and Adjacent Canada. American Book Co., New York.
- Gleason, H. A., and A. Cronquist. 1991. Manual of vascular plants of northeastern United States and adjacent Canada. New York Botanical Garden, Bronx, NY. 910 pp.
- Lesica, P., M. T. Lavin, and P. F. Stickney. 2012. Manual of Montana Vascular Plants. Fort Worth, TX: BRIT Press. viii + 771 p.
- Linnaeus, C. 1753. Species Plantarum. A fascimile of the first edition printed by Adlard & Son, Bartholomew Press, Dorking, Great Britain. 2 vol.
- Weishaupt, C.G. 1971. Vascular Plants of Ohio, Third Ed. Kendall/Hunt Publishing Co. Dubuque, Iowa. B71WEI01PAUS