No. 33. Dirca Palustris.
English Name—SWAMP LEATHERWOOD.
French Name—Dircier triflore.
Vulgar Names—Leatherwood, Moosewood, Swampwood, Ropebark, (Bois de plomb in Canada.)
Authorities—Linnaeus, Pursh, Kalm, Bartram, Duhamel, fig. 212. Torrey, Eaton, Elliott, Locke, B. Barton, Zollickoffer, Bigelow, fig. 37, &c.
Genus DIRCA—Perigone simple, colored or corolliform, tubular, funnelshaped, nearly entire, sub-eight toothed. Stamina eight perigynous, exserted, four alternate longer. Germen free oval, style lateral. Berry one seeded.
Species D. palustris—Shrubby, branches articulated; leaves alternate, subsessile, oval, entire; peduncles triflore drooping.
Description—Shrub, from three to seven feet high, with branches spreading, cylindric, flexuose articulate, green, smooth. Leaves alternate or scattered, distichal, nearly sessile, petioles very short; shape oval entire, acute at both ends, downy when young, smooth and membranous when full grown, pale beneath, unfolding after the flowers.
Flowers blossoming early and before the leaves come out, forming in the fall within terminal buds, where they hybernate, buds with many oblong hairy scales, and three flowers. Peduncle bearing a fascicle of three flowers, formed by three cohering pedicels. Each flower yellow, half an inch long, with a simple perigone, called Corolla by Linnaeus because it is colored: this perigone is drooping, tubular, contracted at the base and middle, campanulate at the end, with eight obscure teeth on the margin. Eight Stamina inserted on the perigone, with slender filaments, longer than the perigone, and alternately longer and shorter, anthers rounded. Germen oval, central free, with a long filiform curved style inserted on one side of the base, Stigma acute. Fruit a small orange berry, oval, acute, with a single seed.
History—One of the few American genera containing as yet a single species. It is a very distinct genus belonging to the natural family of DAPHNIDES, called Thymelea by Jussieu and Vepreculae by Linnaeus, and also to Octandria monogynia of his sexual system. The specific name palustris implies that it grows in swamps; but it is oftener found on the banks of rivers and even among rocks.
The blossoms are scentless and appear very early in the Spring, as soon as the Maples blossoms, long before the leaves are unfolded. The bark is very tough, can hardly be broken, and tearing in long stripes is used as yet in many parts for ropes, a practice borrowed from the Indian tribes: the wood is also flexible. The berries are poisonous, children must avoid them: if eaten by mistake, an emetic must be resorted to.
Locality—From Maine and Canada to Georgia near streams, and in shady swamps, rare west of the Alleghany mountains, yet occuring in Ohio and Kentucky.
Qualities—The bark and root have a peculiar nauseous smell, and unpleasant acrimonious taste; they contain an acrid resin, bitterish extractive, mucilage, &c.: the resin or active principle, is only soluble in boiling alcohol. The decoction and extract are bitter, but not acrimonious.
Properties—Emetic, cathartic, rubefacient, epispastic, &c. and the berries narcotic. The fresh root and bark in substance at the dose of five to ten grains produce vomiting, with a sense of heat in the stomach, and sometimes act as a cathartic also. They are an active and dangerous medicine, to which less acrimonious substances ought to be preferred. Applied to the skin they produce rubefaction and vesication in thirty hours; this appears a more safe mode to use them, as they might become auxiliaries to the Spanish flies. The berries produce nausea, giddiness, stupor, dilatation of the pupil and insensibility like other narcotics. Bigelow considers this plant as a substitute for the Polygala Senega; but this last is by far better and safer, and therefore preferable. We are not told whether it acts like the Polygala and is expectorant, sudorific, &c. Upon the whole this shrub possesses such active properties as to deserve attention; but we do not possess as yet sufficient evidence of its utility. When the bark is chewed it produces salivation, it is so tough that it cannot be reduced to powder, but forms only a kind of lint. The watery preparations are nearly inert.
Substitutes—All the milder emetics and acrid substances, Cantharides—Baptisia tinctoria—Conium maculatum—Polygala senega—Apocynum androsemifolium—Eupatorium perfoliatum—Ranunculus sp.—Euphorbia corollata and E. Ipecacuana—Rhus Sp.—Clematis Sp. &c.
Remarks—Our native epispastics are little known as yet, and deserve attention. The Juglans Cinerea and the Oil of Sassafras are with the Dirca most likely to become practically useful.
We have also in the United States, several species of Cantharides, such as Cantharis Vittata, C. marginata, C. atrata, C. cinerea, &c. which are equal to the officinal Spanish flies, and would be available if not so scarce.
Additions and corrections
33. DIRCA PALUSTRIS—Also called Poisonberry.
Medical Flora, or Manual of the Medical Botany of the United States of North America, 1828, was written by C. S. Rafinesque.