Kendall County (IL) Forest Preserve District
Hemp
(Marijuana)
Cannabis sativa [C-value
0]
Hemp family (Cannabinaceae)
Blooms July -
August
For completeness, we are including this entry for Cannabis sativa although we are not aware of any growing wild in Kendall County. It is native to central Asia and was initially brought to the U.S. for agricultural purposes and is on the Illinois Noxious Weeds List. This annual is about 3-9' tall, unbranched or little branched, with a stout central stem. The lower leaves are often opposite, while the upper leaves are alternate. On large plants, these leaves can span up to 10" long and across. They are palmately compound with 3-9 leaflets. Each leaflet is narrowly ovate and coarsely toothed. Hemp is dioecious with both male and female plants. The male plants produce both axillary and terminal panicles )up to 1' long) of male flowers. Each male flower is about 1/8" across with 5 sepals, 5 stamens with large anthers, and no petals. The female plants produce short axillary spikes (about 1" long) of female flowers, each about 1/8" long with a single sepal, an ovary with two styles, and no petals. The sepal wraps around the ovary, forming a beak; the 2 styles are exerted from the beak.
Terminal panicle of male flowers on a male Hemp plant. These panicles can be up to 1' long (Photo by Dr. John Hilty)
Female Hemp plant with green flowers at leaf axils
Male Hemp plant with panicles of green flowers and very recognizable foliage. (Photo by Dr. John Hilty)
Hemp has been called the "Plant of a Thousand and One Molecules" and has been known since ancient times for its medicinal and textile uses. Hemp is currently witnessing a revival, because of its rich repertoire of phytochemicals, its fibers and its agricultural features including drought and pest resistance. Hemp varieties are also cultivated.for producing oil, biomass or both.
Click here for more information at the Illinois Wildflowers site.
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