Black locust (Robinia pseudoacacia)
Robinia pseudoacacia
Western Herbalism
Western Herbalism

Black locust

Robinia pseudoacacia

Also known as False acacia, Yellow locust, White locust, Locust Tree.

CoolingDryingTaste: BitterTaste: Astringent

Black locust is a fast growing leguminous tree native to the eastern and central United States, now widely naturalized elsewhere, valued chiefly for timber, erosion control and bee forage. The fresh inner bark was tinctured by a handful of nineteenth century Eclectic physicians who found its action strong enough to note but never developed it into a settled clinical remedy. It survives in the record mainly as an unfinished experiment rather than an established materia medica entry.

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Purgative in large doseEmetic in large doseGastrointestinal irritantCNS depressant reported historicallyAntispasmodic claimed historicallyVermifuge claimed historically

Indications what the tradition reached for it in

Specific indications

Sluggish, torpid bowel with little other reliable indication recorded

Historical use where nervous system depression was thought to accompany gastrointestinal upset

Safety

Recognised toxicity. This plant carries a toxicity flag in the record; it is for trained practitioners only.

Low dose botanical. Used in drop doses in the classical practice; not a plant to dose freely.

Pregnancy: Avoid entirely: the plant has no established modern therapeutic use and its bark and seeds carry documented toxicity.

Breastfeeding: Avoid entirely: no safety data exist and the plant is not used in modern lactation practice.

The record lists 6 contraindications; open the plate in the library to read them in full.

In practice

This plant never entered mainstream Eclectic or later herbal practice as a working remedy. The original note describing the tincture explicitly asks readers to test it and report back, which they largely did not do in any way that produced a durable clinical picture. What little is recorded describes a strong action on the stomach and bowel in large doses along with some effect on the nervous system, but no reliable specific indication, dose-response relationship or safety profile was ever worked out. Given this, black locust bark cannot be recommended today as a working remedy. Any historical dose figures should be read as a curiosity of record rather than a guide to safe practice, particularly because the seeds and bark of this species are now known to contain toxic lectins capable of causing significant gastrointestinal and systemic illness.

Dosing as the sources wrote it

PreparationAs writtenMetric
Historical tincture (fresh inner bark, 1:X in 76 percent alcohol, Scudder era)0.05-0.6 mL per dose, historical figure only, not a modern recommendation0.05-0.6 mL
An ounce of the bark boiled inAn ounce of the bark boiled in 3 gills of water, operates as a cathartic in doses of ½ ounce, given morning and evening.15552-15552 mg
The leaves, in doses of 30 grains, every 20 minutes, operate mildly and efficiently as an emetic.1944-1944 mg

Doses are reproduced from the sources for practitioners and are not a recommendation for any person.

From the sources

Overview. Black locust is a fast growing leguminous tree native to the eastern and central United States, now widely naturalized elsewhere, valued chiefly for timber, erosion control and bee forage. The fresh inner bark was tinctured by a handful of nineteenth century Eclectic physicians who found its action strong enough to note but never developed it into a settled clinical remedy. It survives in the record mainly as an unfinished experiment rather than an established materia medica entry.

Clinical Notes. This plant never entered mainstream Eclectic or later herbal practice as a working remedy. The original note describing the tincture explicitly asks readers to test it and report back, which they largely did not do in any way that produced a durable clinical picture.

Specific indications and reasoning. (BLACK LOCUST.) Preparation: Prepare a tincture from the fresh inner bark of the Black Locust, 3viij. to Alcobol 76º Oj. Dose from gtts. j. to gtts. x. This remedy has been but little used, yet its activity is such that we may reasonably expect that experiment will develop some valuable medicinal use. It acts on the stomach aud bowels in large doses, and exerts an influence upon the nervous system. Will some of our readers test it and report?

Drawn from Scudder's Specific Medication and Specific Medicines; King's American Dispensatory, 18th edition (Felter and Lloyd), and the Bountiful Herbs editorial.

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