Viburnum prunifolium
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| Viburnum prunifolium L. |
Black haw, also spelled blackhaw, Blackhaw Viburnum, or Stag Bush (Viburnum prunifolium), is a small tree native to southern North America. It has both value in the pleasure garden, providing good fall color and early winter provender for birds, and medicinal properties.
Taxonomy
Black haw has the scientific name Viburnum prunifolium. It was originally classified in the family Caprifoliaceae. After genetic testing by the Angiosperm Phylogeny Group, the genus Viburnum was moved to the family Adoxaceae.
Description
Black haw is a small deciduous tree or shrub[1] with a short crooked trunk ans stout spreading branches.[2] Like many species of Prunus, it has oval leaves with serrated edges—[1] thus "prunifolium"— showy pale-colored flowers,[3] and dark blue-black berries[1] that are eaten by birds. The bark is reddish-brown in color.[3] In the northern parts of its range, V. prunifolium is a shrub, becoming a small tree in the southern parts of its range. Wherever it lives, black haw prefers sunny woodland with well-drained soil and adequate water.[3] The tree is deciduous; its leaves turn red in fall.[3]
- Bark: Reddish brown, scaly. Branchlets at first red, then green, finally dark brown tinged with red.
- Wood: Brown tinged with red; heavy, hard, close-grained. Sp. gr., 0.8332; weight of cu. ft., 51.92 lbs.
- Winter buds: Coated with rusty tomentum. Flower-buds ovate, half an inch long, much larger than the axillary buds. Scales grow with the growing shoot and sometimes develop into leaf-like bodies.
- Leaves: Opposite, simple, oval, ovate or orbicular, two to three inches long, wedge-shaped or rounded at base, serrate, acute. Feather-veined, midrib and primary veins prominent beneath. They come out of the bud involute, shining, green, tinged with red, sometimes smooth, or clothed with rusty tomentum; when full grown dark green and smooth above, pale, smooth or tomentose beneath. IN autumn the leaves vary from scarlet to a vinous red. Petioles short, grooved, red, often tomentose, sometimes winged.
- Flowers: May. Perfect, cream-white, borne in flat-topped cymes three to four inches in diameter. The pedicels are bibracteolate; bracts are awl-shaped, short, reddish, caducous.
- Calyx: Urn-shaped, five-toothed, persistent.
- Corolla: White, five-lobed; lobes rounded, imbricate in bud.
- Stamens: Five, exserted, inserted on the base of the corolla, alternate with the lobes; filaments slender; antehrs pale yellow, oblong, introrse, versatile, two-celled; cells opening longitudinally.
- Pistil: Ovary inferior, one-celled; style thick, pale green; stigma flat; ovules one in each cell.
- Fruit: Drupe, oval, half an inch long, dark blue, with glaucous bloom. Ripens in October, borne in few-fruited clusters, hangs until winter, becomes edible after being touched by the frost. Stone flat and even, broadly oval.[2]
Medicinal uses
For centuries, black haw has been used for medical purposes, mainly for gynecological conditions. The bark is the part of the plant used in treatments.[1]
The active components include scopoletin, aesculetin, salicin, 1-methyl-2,3 clibutyl hemimellitate, and viburnin. Tannin is another chemical component of black haw.[1]
Native Americans used a decoction of black haw to treat gynecological conditions, including menstrual cramps, aiding recovery after childbirth, and in treating the effects of menopause.[3] As a folk remedy, black haw has been used to treat menstrual pain, and morning sickness. Due to its antispasmodic properties, the plant may also be of use in treating cramps of the digestive tract or the bile ducts.[1]
Black haw's primary use was to prevent miscarriages.[1] American slaveholders also used the plant to prevent abortions. Slaves were a valuable asset, and their owner also owned their offspring, so ensuring that female slaves gave birth was of paramount importance. In defiance, some slave women would attempt to use cotton seeds to cause a miscarriage. The slaveowners would therefore force pregnant slaves to drink an infusion of black haw to prevent that.[3]
The primary use of black haw today is to prevent menstrual cramps. The salicin in black haw may also be of use in pain relief.[3]
Safety issues
As black haw contains salicin, a chemical relative of aspirin, people who are allergic to that substance should not use black haw.[1] In addition, due to the connection between aspirin and Reye's syndrome, young people or people afflicted with a viral disease should not use black haw.
The chemicals in black haw do relax the uterus and therefore probably prevent miscarriage; however, the salicin may be teratogenic. Consequently, pregnant women should not use black haw.[3] Furthermore, anyone using herbs for medical reasons should only use them under the supervision of a qualified medical professional.
Black haw is not on the FDA's "generally recognized as safe list".[4]
References
- ↑ 1.0 1.1 1.2 1.3 1.4 1.5 1.6 1.7 Andrew Chevallier (1996). The Encyclopedia of Medicinal Plants: A practical reference guide to more than 550 key medicinal plants and their uses. Reader's Digest. p. 279. ISBN 0-88850-546-9.
- ↑ 2.0 2.1 Keeler, Harriet L. (1900). Our Native Trees and How to Identify Them. New York: Charles Scriber's Sons. p. 184.
- ↑ 3.0 3.1 3.2 3.3 3.4 3.5 3.6 3.7 Michael Castleman (1991). The Healing Herbs. Rodale Press. pp. 79–81. ISBN 0-87858-934-6.
- ↑ "SUBSTANCES GENERALLY RECOGNIZED AS SAFE". Code of Federal Regulations - Title 21, Volume 6. Food and Drug Administration. 2006-04-01. Retrieved 2007-03-08.