Cannabis is a noxious weed in Illinois. The Illinois Noxious Weed law mandates that each landowner controls the spread of and/or eradicates this plant from their land. This plant spreads by seed. It commonly grows in disturbed sites and grasslands but can become acclimated to a variety of habitats. It is native to Eastern Asia, and today can be found inside and outside of cultivated areas across the United States. Because of widespread cultivation, the plant is very likely to escape and grow in areas where it was not planted. When used recreationally, it can become addictive and causes a variety of short-term and long-term effects to the brain and body.
The legal status of cannabis varies from state to state. Check with local authorities regarding legal status.
More Information
Size and Method of Spreading
The average height of a plant is about 5 feet, but it can range in size from 3 to 20 feet tall.
Leaf Description
The thin, green leaves are compound with an alternate arrangement. Lower leaves may sometimes be opposite. Plants have five to seven leaflets that originate from the center (palmate shape). The leaflets have deep horizontal veins (pinnate venation) and toothed edges (serrated leaf margins).
Flower Description
The small flowers of cannabis are light green. Male and female flowers are on different plants (dioecious). Male flowers may be found in the leaf axils and in branched terminal clusters (panicles). Female flowers are produced in short spikes in the leaf axils.
Fruit Description
The fruit of the plant is a small, dry seed (achene) typically developing near the leaves, sometimes hanging from a short stem.
General Management
For more information on management of this plant, contact The Morton Arboretum Plant Clinic (630-719-2424 or plantclinic@mortonarb.org).
