Barosma crenata. (Diosma Crenata.) Buchu.
Nat. Ord. — Rutaceae. Sex. Syst. — Pentandria Monogynia.
Description. — This plant formerly belonged to the genus Diosma, but has been transferred by Botanists to that of Barosma. It, is a slender, smooth, upright, perennial shrub, between two and three feet in hight, with twiggy, somewhat angular branches, of a brownish-purple color. The leaves are opposite, spreading, about an inch long, ovate, acute, on very short petioles, very obtuse, delicately and minutely crenated, quite glabrous, rigid, darkish-green and quite smooth above, with a very few obscure, oblique nerves, beneath paler, dotted with glands which are scarcely pellucid, while at every crenature is a conspicuous pellucid gland. The flowers are whitish, or of a pale-reddish color, solitary, on short pedicels at the ends of short lateral shoots. The calyx has live ovate-acuminate, persistent sepals, green, tinged with purple, beneath which are two or three pairs of small imbricated bracteae. The corolla has five elliptic, oblong, bluntish petals, somewhat spreading, which are purple when in bud, and blush-colored when fully expanded. The stamens are five, subulate, and bearing ovate, incumbent anthers ; filaments slightly villous. The ovary is superior, turbinate, supporting an erect style crowned with a minute, five-lobed stigma. The capsule is ovate, containing a single, oblong, black, shining seed, with an elastic testa.
History. — This plant is a native of southern Africa, the officinal part of which is the leaf. There are several varieties from which the leaves are obtained, as the Barosma Crenata, B. Crenulata, B. Serratifolia, etc. The leaves are odoriferous, and when powdered are termed by the Hottentots, Booko or Buchu, and are used by them to rub upon their greasy bodies. They likewise prepare a Buchu Brandy by distilling the leaves with wine, and which they employ as an efficient remedy in all affections of the stomach, bowels, and bladder ; they also apply a decoction of the leaves to wounds.
As found in our markets, the leaves are from three-quarters of an inch to an inch in length, from three to five lines broad, elliptical, lanceolate-ovate, or obovate, sometimes slightly pointed, sometimes blunt at the apex, very finely notched and glandular at the edges, smooth, green on their upper surface, dotted and paler beneath, and of a firm consistence. They have a strong, diffusive, aromatic odor, with very faint bitterness ; the taste and odor being somewhat allied to pennyroyal, and which will serve to distinguish them from senna leaves. If they be preserved with ordinary care, their odor will remain for some years. The leaves of the B. Serratifolia may be known by their linear-lanceolate form, and serrulate edges ; and those of the B. Crenulata much resemble those of the B. Crenata, but are oblong-ovate, and have a narrow pellucid margin around the whole leaf. They all possess similar properties. Analysis has detected in them, a light, yellowish-brown, and highly odorous volatile oil, gum, extractive, which is precipitated by infusion of galls, chlorophylle and resin. Water or alcohol extracts their virtues, which are chiefly dependent on the volatile oil and extractive.
Properties and Uses. — Buchu is a stimulant, diuretic, antispasmodic, and tonic. Useful in all diseases of the urinary organs attended with increased uric acid ; in irritation of the bladder and urethra attending gravel, in catarrh of the urinary bladder, and incontinence connected with diseased prostate. It has also been recommended in dyspepsia, dropsy, cutaneous affections, and chronic rheumatism. I do not, however, think it equal to many of our indigenous remedies, which are sadly neglected by the profession, in their eagerness for something at a distance from home. Were our native plants more closely investigated, there would be but little use for foreign, and consequently expensive agents. Under favorable circumstances a warm infusion of Buchu leaves, will cause diaphoresis. Dose of the powder, from twenty to thirty grains, two or three times a day ; of the infusion, two to four ounces, three or four times a day ; of the tincture, one to two fluidrachms.
Off. Prep. — Extractum Barosmae vel Buchu Fluidum ; Infusum Barosmae.