This section is from the book "A Manual Of Weeds", by Ada E. Georgia. Also available from Amazon: A Manual Of Weeds.
Introduced. Annual. Propagates by seeds. Time of bloom: July to September. Seed-time: August to November.
Range: New Brunswick to Ontario and Minnesota, southward to North Carolina, Tennessee, and Kansas. Habitat: Barnyards, waste places.
Seeds of hemp are often an impurity of other seeds, notably of oats, particularly if grown in the hemp-raising districts of the country. The writer first saw the plant flourishing finely in a vacant lot behind a city livery stable. (Fig. 47.)
Stem three to ten feet in height, rather stout, erect and holding its branches nearly upright, the inner bark fibrous and extremely tough and strong, the whole plant rough-hairy and strong-scented. Leaves compound, with five to seven very slender leaflets, attached to their foot-stalk like fingers, all at the same base; leaflets three to six inches in length, a quarter-inch to an inch wide, pointed at both ends, sharply toothed. Flowers dioecious, the sterile ones in axillary, compound panicles, each with five hairy sepals and five drooping stamens; the fertile ones in small, erect, axillary spikes, leafy-bracted, the calyx entire and clasping the ovary. Achene compressed ovoid, about an eighth of an inch long.
Fig. 47. - Hemp (Cannabis sativa).
Prevent seed development by cutting or pulling while the plant is in early bloom.