# Black haw (Viburnum prunifolium)

*Sloe, stag bush, sloe-leaved viburnum; *Viburnum prunifolium* L.*

**Known today as.** *Viburnum prunifolium*, a North American shrub or small tree ten to twenty feet high, of the honeysuckle family, growing in dry woods, thickets, and rocky hillsides from Connecticut to Illinois and most abundantly in the south. Its spreading, rather stunted branches give it, King’s Dispensatory says, “an unthrifty appearance”; it bears white flowers in large flat clusters from March to June, and sweet, edible, blackish berries. The bark of the root, stem, and branches is the drug, the root bark preferred by the Eclectics; it is bitter and slightly aromatic.

Kind: Plant

> **Caution.** King’s notes that large doses sometimes cause nausea and vomiting, and that some observers said it made the muscle of the womb contract, though it was used to prevent miscarriage. None of the modern sources read for this entry reports on its safety, in pregnancy or otherwise.

## What was it used for?

A remedy for the womb. King’s, in 1898, calls it “the most valuable of the genus Viburnum,” brought forward by Dr. D. L. Phares of Mississippi as nervine, antispasmodic, tonic, astringent, and diuretic, and used chiefly for painful, cramping menstruation, uterine bleeding at the menopause, cramps of the legs, and above all threatened and habitual miscarriage, for which it calls it “the most prompt drug in the materia medica,” provided the membranes had not ruptured.

## What does modern science say?

No European monograph covers it, and the searches of Europe PMC made for this entry found no clinical trial of black haw. King’s itself admitted in 1898 that “of the physiological action of this agent little is known.”

## Pharmacognosy and toxicology

- **bitter resin**: a brown one and a greenish-yellow one, in Van Allen’s analysis of the bark
- **tannic acid**: with oxalic, citric, and malic acids

**Mechanism.** Little known; King’s wrote in 1898 that “of the physiological action of this agent little is known.”

**Standing.** There is no European monograph. It was official in the United States Pharmacopoeia in 1898; no clinical trial of it was found for this entry.

## What lore surrounds it?

Its bark was much substituted. Smith, in 1932, notes that nannyberry was often sold as black haw, and judged of the class that “the virtues assigned to this class of medicine are as feeble as they are numerous”; he also found mountain maple bark sold for cramp bark, “about as effective as a uterine sedative and preventative of abortion.” Grieve wrote that cramp bark, from the guelder rose, has the same constituents as black haw but is considered much weaker.

## What did the older authorities say?

**Felter and Lloyd, *King’s American Dispensatory* (1898).** King’s records, from Scudder, that “it was for a long time customary for planters to compel their female slaves ‘to drink an infusion of black haw daily whilst pregnant to prevent abortion, from taking the cotton-root’”; Phares held that it would neutralise cotton-root bark taken to cause miscarriage. The passage implies that enslaved women were taking cotton root to end their pregnancies, and that slaveholders forced black haw on them to prevent it.

## Sources

- Felter, H. W., & Lloyd, J. U. (1898). *King’s American Dispensatory*, vol. 2, “Viburnum prunifolium.” Internet Archive, kingsamericandis02kinguoft.
- Smith, H. H. (1932). *Ethnobotany of the Ojibwe Indians*, Nannyberry. Bulletin of the Public Museum of the City of Milwaukee 4. Project Gutenberg, 49527.
- Grieve, M. *A Modern Herbal*, “Guelder Rose.” As published on botanical.com.
- Felter, H. W., & Lloyd, J. U. (1898). *King’s American Dispensatory*, vol. 2, “Viburnum prunifolium.” Internet Archive, kingsamericandis02kinguoft.

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*Black haw.* In *Materia Medica*, edited by B. C. P. Statema. Version 1, revised 2026-10-17. The Thinking Press. https://thethinkingpress.org/materia-medica/black-haw

Historical description, not medical advice.