Cannabis sativa (Hemp)
|Also known as:||Ditchweed, Marijuana|
|Habitat:||part shade, sun; fields, ditches, along roads, disturbed soil|
|Bloom season:||June - October|
|Plant height:||3 to 9 feet|
|Wetland Indicator Status:||none|
|MN county distribution (click map to enlarge):|
|National distribution (click map to enlarge):|
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Hemp has both male and female flowers, usually on separate plants but both may be on the same plant. The male flowers are greenish and become cream or pale yellow with maturity, are ½-inch across when fully opened, hanging down with 5 widely spreading narrow petals and 5 creamy-tipped stamens, and loosely clustered on branching stems up to 12 inches long.
Leaves and stems:
Leaves are in a fan-shaped array, palmately compound in groups of 3 to 9, alternately attached at the stem, though they may be oppositely attached near the base of the plant. Leaflets are linear to narrowly elliptic, tapering to a point at each end, coarsely serrated, with short stiff hairs on the surface. Leaflets in the middle of the fan are longer than those on the end. On a large male plant the middle leaflets may be up to 12 inches long and 1 inch wide. A female plant has smaller leaves, more tightly clustered at the stem but is generally more robust than male plants. Stems are smooth and green, sometimes tinged red.
Hemp is sometimes referred to as "Industrial Hemp" for its uses such as making rope, fabric, and paper, or for its food value. Plants found in the wild are often leftovers from the days when it was a farm crop and do not typically have the "recreational" value of Marijuana, though I did once come upon a secret stash of Marijuana growing in 5-gallon pails at Boot Lake SNA in northern Anoka County. Whoever had placed them there was either very clever or very dumb, as they were located in the middle of a patch of Poison Sumac! Hemp is considered a noxious weed in Koochiching, Murray and Waseca counties of Minnesota, though there are no official records of its existence in those particular counties. It is likely a very under-reported species. There is some debate regarding subspecies, but when recognized, subsp. indica (also known as Cannabis indica) is generally considered a more compact plant with broader leaflets, where subsp. sativa has narrow leaflets. The chemical composition of the two is also rather different with indica apparently the more intoxicating of the two.
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- Wild Hemp plants
- a male and a female plant
- more plants
- early growth
- clusters of male flowers
- clusters of female flowers
- subsp. indica leaves
Photos by K. Chayka taken at Long Lake Regional Park, Ramsey County. Other photos courtesy Peter M. Dziuk.
Have you seen this plant in Minnesota, or have any other comments about it?