Category: Medicines - plant based
Introduction and description
Viburnum prunifolium (known as blackhaw or black haw, blackhaw viburnum, sweet haw, and stag bush) is an attractive shrub or small tree, known for its ‘value in the pleasure garden’, providing good autumn colour and early winter provender for birds. It is also widely known for its medicinal properties.
Many of its medicinal uses, as an anti-inflammatory for example are due to the presence of Salicyclic acid, but renewed interest in the plant has occurred as more is known about the properties of salicyclic acid. It is being explored, for example, as treatment for colorectal cancer.
Viburnum prunifolium is native to eastern North America, from Connecticut west to eastern Kansas, and south to Alabama and Texas. Wherever it lives, black haw prefers sunny woodland with well-drained soil and adequate water.
Viburnum prunifolium is a deciduous shrub or small tree growing to 2–9 m tall with a short crooked trunk and stout spreading branches; in the northern parts of its range, it is a shrub, becoming a small tree in the southern parts of its range.
The bark is reddish-brown, very rough on old stems. The branchlets are red at first, then green, finally dark brown tinged with red. The winter buds are coated with rusty tomentum. The flower buds ovate, 1 cm long, are much larger than the axillary buds.
The flowers are creamy white, 9 mm diameter; the calyx is urn-shaped, five-toothed, persistent; the corolla is five-lobed, with rounded lobes, imbricate in bud; the five stamens alternate with the corolla lobes, the filaments slender, the anthers pale yellow, oblong, two-celled, the cells opening longitudinally; the ovary is inferior, one-celled, with a thick, pale green style and a flat stigma and a single ovule. The flowers are borne in flat-topped cymes 10 cm in diameter in mid to late spring.
The leaves are simple, up to 9 cm long and 6 cm broad, oval, ovate or orbicular, wedge-shaped or rounded at base, serrate, acute, with serrated edges with a grooved and slightly winged red petiole 1.5 cm long; they turn red in the autumn. The leaves are superficially similar to some species of Prunus (thus "prunifolium"); 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.
The fruit is a drupe 1 cm long, dark blue-black with glaucous bloom, hangs until winter, becomes edible after being frosted, then eaten by birds; the stone is flat and even, broadly oval.
For centuries, black haw has been used for medical purposes, mainly by Native American Indians. The bark is the part of the plant used in treatments.
The active components, besides the salicyclic acid include scopoletin, aesculetin, salicin, 1-methyl-2,3 clibutyl hemimellitate, and viburnin. Tannin is another chemical component of black haw. The tannin content give it metal chelating ability, which means the bush is a potential bio-remedial plant.
Native Americans used a decoction of black haw to treat gynaecological conditions, including menstrual cramps, aiding recovery after childbirth, and in treating the effects of menopause. According to Dr Duke's analysis, there are chemicals in the plant [mostly the bark] that are both Uterorelaxant and Abortifacient - can cause abortions. The Salicyclic acid - again according to his analysis is
Aldose-Reductase-Inhibitor 724.6 uM; Analgesic; Antiarthritic; Antibacterial; Antidandruff; Antidermatotic; Antieczemic; Antiichthyosic; Antiinflammatory; Antineuralgic; Antioncychomycotic; Antioxidant; Antiperiodic; Antipodagric; Antipsoriac; Antipyretic; Antirheumatic; Antiseborrheic; Antiseptic; Antitumor; Antitympanitic; Cancer-Preventive; Comedolytic; COX-2-Inhibitor; Cyclooxygenase-Inhibitor; Dermatitigenic; Fungicide MIC 1,000 ug/ml; Hypoglycemic; Insectifuge; Keratolytic; Pesticide; Thermogenic 130 ppm; Tineacide; Ulcerogenic
The observations provide details of the scientific research done on the actual medicinal properties of the plant. It may also be useful to turn to the section on Salicyclic acid.
References and further reading
- [On new substances contained in the back of Viburnum prunifolium L. (American guelder-rose) and Viburnum opulus L (common guelder-rose)]. Hörhammer L, Wagner H, Reinhardt H. Z Naturforsch B. 1967 Jul;22(7):768-76. German. PMID: 4385312
- Scopoletin, an Antispasmodic Component of Viburnum opulus and prunifolium.- Jarboe CH, Zirvi KA, Nicholson JA, Schmidt CM. J Med Chem. 1967 May 1;10(3):488-9. doi: 10.1021/jm00315a045. PMID: 22185161
- [RESEARCH ON THE UTERINE ACTION OF VIBURNUM PRUNIFOLIUM]. BALDINI L, BRAMBILLA G, PARODI S. Arch Ital Sci Farmacol. 1964 Jan;14:55-63. Italian. PMID: 14292799
- The identification of an acid in the root bark of Viburnum prunifolium. HOLBERT JM. J Am Pharm Assoc Am Pharm Assoc. 1946 Oct;35(10):315. PMID: 21002919
- Viburnum Prunifolium, or Black Haw, in Abortion and Miscarriage. Wilson JH. Br Med J. 1886 Apr 3;1(1318):640-1. PMID: 20751515
- Viburnum Prunifolium in Abortion. Napier AD. Br Med J. 1886 Mar 13;1(1315):489-90. PMID: 20751494
- Dr Duke's list of Chemicals and their Biological Activities in: Viburnum prunifolium L. (Caprifoliaceae) -- Black Haw 020499
- Dr Duke's list of Plants containing SALICYLIC ACID 020467