Hemp (Cannabis sativa): other Minnesota wildflowers

Hemp

Plant Info
Also known as:	Ditchweed
Scientific name:	Cannabis sativa
Family:	Hemp (Cannabaceae)
Life cycle:	annual
Origin:	Asia
Habitat:	sun; fields, ditches, along roads
Bloom season:	summer
Plant height:	3 to 9 feet
Spotted in Ramsey County at:	Long Lake Regional Park

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Flower:: 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. Individual flowers are ¼-inch across closed and ½-inch when opened, loosely clustered on branching stems up to 12 inches long. The branches may be reddish green.
The female flowers are green, in dense clusters along the stem and at the top of the plant.
Leaves:: Hemp leaves may be the most recognizable on the planet, since it is the symbol for marijuana. A fan of 3 to 9 narrow leaves are alternately attached at the stem, though they may be oppositely attached near the base of the plant. Each leaf is coarsely serrated; the leaves in the middle of the fan are longer than those on the end. On a large male plant the middle leaves may be up to 12 inches long. A female plant has smaller leaves, more tightly clustered at the main stem.
Notes:: Wild Hemp is on the noxious weed list for Minnesota. It is in the same family as marijuana, but has only tiny levels of THC thus it is not cultivated for recreational reasons. It is often referred to as "Industrial Hemp" for its other 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. Also note that the photos of male plants here were taken in July, the female photos in September.