Hemp, Canadian

Medical Herbs Catalogue


Hemp, Canadian

Botanical Name: Apocynum Cannabinum (LINN.), Apocynum Androsaemum
Family: N.O. Apocynaceae

Synonyms: Black Indian Hemp. Dogsbane.
Parts Used: Dried rhizome, roots.
Habitat: United States of America, Canada.

Description: This plant must not be confused with Indian Hemp (Cannabis Indica). Both species have a milky juice and a tough fibrous bark, which when macerated affords a substitute for hemp, hence its common name. It is used in California for making twine, bags, cordage, fishing-nets, lines, and a coarse kind of linen. When the milky juice is properly dried it exhibits the properties of india-rubber. The corolla of this plant secretes a sweet liquid, which attracts flies and other insects to settle on them; the scales in the throat of the corolla are very sensitive, and as soon as the insects settle on them, they bend inwards and make them prisoners. None of these plants possess any great beauty, all are more or less poisonous and acrid. In Apocynum Cannabinum, a perennial herb, the stems and branches are upright, headed by erect many-flowered stems, leaves nearly sessile; it grows in gravelly or sandy soil, mostly near streams. While A. Androsaemifolium, or Dogsbane, has spreading forked branches, leaves slender petioled cymes, loose and spreading, grows in dry thickets and open woods, and is distinguished from A. Cannabinum by the root, thick-walled stone cells which are arranged in a broken circle, near middle of the bark, short fracture, with some pith occurring in pieces of the rhizome, very slight odour, taste starchy, afterwards bitter and acrid.

Constituents: The activity of the plants is due to a very bitter principle of a glucose nature to which is applied the name of Symarin. Apocynum belongs to the digitalis group of heart tonics, and acts very much in the same way, differing only from foxglove in the relative degree of its different effects. It is the most powerful of the group, often causing sickness and diarrhoea; it acts more irritantly on the mucous membrane than either strophanthus, or digitalis, and it may be this stimulating effect which is the cause of its violent diuretic action, though some authorities consider that this is caused by dilatation of the renal arteries. A. Docynum is the crystalline lactone cynotoxin, the crystalline substance. Apocynin is identical with acetovanillone. A. Androsaemifolium contains apocyanamarin, identical with cynotoxin, also apocynin and its glucoside, androsin ipuranil; the two phytosterols androsterol and homo-androsterol, and other fatty acids.

Medicinal Action and Uses: Diuretic, diaphoretic, expectorant. Should only be prescribed with the greatest caution. It is a very valuable heart tonic of great service in dropsy resulting from heart failure; it is also to be highly recommended in the ascites of hepatic cirrhosis, but care must be taken that it does not accumulate in the system. It causes violent vomiting.

Dosage: 1 to 5 grains.

Preparations: Fluid extract of Apocynum, U.S.P., 15 minims. Tincture of Apocynum, 5 to 10 minims.

Other Species:
HEMP, AFRICAN, or Bowstring (Sanseviera guineenesis, N.O. Liliaceae), native of tropical Africa, also S. Roxburghiana, a native of India, and S. Angolensis, native of western tropical Africa. The leaves contain much fibre for making ropes, the latter producing the best kind of fibre for deep-sea soundings and dredging lines.

HEMP, KENTUCKY (Urtica Canadensis and Cannabina, N. O. Urticaceae), natives of Canada and Northern U.S. These also contain a strong fibre and are known by the name given above.

HEMP, MANILLA, the fibre of Musitextilis (N.O. Musaceae), native of the Philippines, cultivated in India, and other countries, for its fibre, of which there are two qualities, the finer made into shawls and the coarser into ropes.

HEMP, SUNN, the Indian name for the fibre of Crotalaria Juncea (N.O. Leguminosae), native of India; it gives a very strong fibre, useful for ropes, canvas, etc.

HEMP, JUBBULPORE (Crotalaria tenuifolia), The plant closely resembles Sunn Hemp (C. Juncea).