Prunus serotina, Ehrhart. The stem-bark collected in autumn and carefully dried. Borke (ross-sloughing dead tissues), if present, should be removed.

Habitat. N. America (Can.to Fla., to Minn., Neb., Kan., La., to Texas), in woods.

Syn. Prun. Virg., Wild Black Charry Bark, Cabinet (Rum, Whisky, Blackchoke, Wild) Cherry; Br. Pruni Virginianae Cortex, Virginian Prune Bark; Fr. Ecorce de Cerisier de Virginie; Ger. Wildkirschenrinde.

Pru'nus. L. fr...., a plum tree; prunum, a plum, -- i.e., classic name.

Se-rot'i-na. L. serotinus, fr. serus, late -- i.e., the latest of the genus to bloom and fruit. Vir-gin-i-a'na. L. of or belonging to Virginia -- i.e., Virginian.

Plant

Large tree 9-24 M. (30-80 degrees) high; trunk regular, straight, with blackish, rugged outside bark, that of young branches smooth, red or purplish; leaves 5-12.5 Cm. (2-5') long, oval, petiolate, serrate, teeth glandular, glabrous, shining, bright green, with 2 small glands on the margin at the base; flowers May-June, appearing after the leaves, small, white racemes; fruit August, drupe, size of a pea, purplish-black, pulpy, sweet, acidulous, slightly astringent and bitter -- bitter cherries; seed subglobular bitter almond flavor, containing bland, yellowish-green fixed oil 25 p.c. BARK, usually in transversely curved pieces, 2.5-8 Cm. (1-3 1/5') long, 12-25 Mm. (1/2-1') broad, .5-8 Mm. (1/50-1/2') thick; outer surface (rossed bark) light brown, greenish-brown, smooth, except numerous lentical-scars (unrossed bark), reddish-brown, glossy, smooth, with light colored, transversely elongated lenticels, roughened, flaky with gray lichens; inner surface light brown, with delicate, reticulate striations, numerous minute fissures; fracture short, granular; odor distinct, resembling bitter almond when macerated in water; taste astringent, aromatic, agreeable bitter.

Powder

light brown -- fragments of yellow-brown cork, stone cells, few bast-fibers, not greatly elongated, frequently accompanied by crystal-bearing fibers, calcium oxalate prisms, rosette aggregates, starch grains .002-.015 Mm. (1/12500-1/1665 broad. Young, thin bark best, and that from very large or small branches should be rejected. Should be kept dark, in tightly-closed containers. Solvents: hot or cold water. Dose, 3ss-1 (2-4 Gm.).

Adulterations

Unrossed bark, that of old stems, also that of choke cherry, which closely resembles the official, but as a rule is either thinner or thicker, and breaks with a very tough fracture like slippery elm.

Commercial

The Latin official name, from its long usage, has been retained, although misleading; Prunus virginiana was given early by Linnaeus to Choke Cherry, a shrub 2.5-3 M. (8-10 degrees) high, having more sharply-toothed leaves, shorter racemes, and astringent, dark red, crimson fruit, size of wild cherry. It has received various names at different times, as Prunus ru'bra, P. obova'ta, P. virginiana, P. serotina, Cerasus serotina, C. virginiana. The true official Prunus serotina grows in fertile soil in fields, woods, along fences, seldom in clusters; wood is valuable for furniture, being hard, red, fine-grained, and easily polished. Bark after collection is (rossed) deprived of outside layer (periderm or ross -- cork and parenchymatous cells), exposing green phelloderm, and then dried; while that from all portions of the tree is used, that from the root is strongest, yet it all soon deteriorates, consequently only the fresh-dried should be employed; the average bark collected in April yields most starch, but least tannin, and hydrocyanic acid -- .0478 p.c.; in June -- .0956 p.c.; in Oct. -- .1436 p.c. or 1/7 gr. (.009 Gm.) From 100 gr. (6.5 Gm.) bark, which equals 7-8 m (.5 cc.) of 2 p.c. acid; some bark reverse these seasonal percentages; young bark may yield of acid .183-.250 p.c., old bark, .159-.335 p.c.

Constituents

Amygdalin, Emulsin, Bitter principle, tannin 2-4.5 p.c., gallic acid, resin, starch, (volatile oil, hydrocyanic acid, benzoic acid from oxidation of benzaldehyde?)

Amygdalin. -- Cyanogenetic glucoside, similar to laurocerasin (prulaurasin) obtained by the action of alcohol; it is bitter, non-crystalline, and not precipitated by ether, hence in this differs from that in bitter almond.

Emulsin. -- Enzyme or ferment, identical with emulsin or synaptase, extracted by water; white powder when pure, and by its action on amygdalin, in the presence of water, develops hydrocyanic acid and the volatile oil of bitter almond, neither of which, as such, existed previously in the bark. These two are obtained also by distilling the seed with water, when they come over more or less mixed. The poisonous property of the oil depends largely upon the amount of acid present, and when freed of this, the oil becomes a bland, colorless liquid resembling that from bitter almond. Some think the ferment neither emulsin nor synaptase, but a closely analogous compound.

Bitter Principle. -- Obtained by mixing soft aqueous extract with alcohol, shaking with milk of lime, evaporating filtrate, boiling residue with alcohol, evaporating, getting brown, bitter, gelatinous mass, which is insoluble in ether, soluble in alcohol, brownish-red with sulphuric acid

Preparations

1. Syrupus Pruni Virginianae. Syrup of Wild Cherry. (Syn., Syr. Prun. Virg.; Br. Syrup of Virginian Prune; Fr. Sirop d'Ecorce de Cerisier; Ger. Wildkirschenrindensirup.).

Manufacture

15 p.c. Mix glycerin 5 cc. with water 20, moisten wild cherry bark 15 Gm. with 10 cc. of mixture, pack in percolator, add remainder of mixture, and enough water to saturate and leave stratum above, macerate for 24 hours, percolate with water into sucrose 80 Gm. q.s. 100 cc., dissolve by aggitation without heat. Should be kept cool, in non-metallic, tightly-closed containers, as it rapidly loses hydrocyanic acid under favorable conditions. Dose, 3j-4 (4-15 cc.); mainly for flavoring.

2. Fluidextractum Pruni Virginianae, N.F., moisten, 100 Gm., with glycerin 20 cc. + water 40, pack, macerate 24 hours; percolate with alcohol 25 cc. + water 15, finally with 25 p.c. alcohol q.s., 100 cc. Dose, 3ss-12 (2-4 cc.): Prep.: 1. Elixir Taraxaci Compositum, N.F., 3.5 p.c.

3. Syrupus Pini Albae Compositus, N.F., 8.5 p.c.

Unoff. Preps.: Infusion, 4 p.c., dose, 3ss-2 (215-60 cc.). Tinctura Pruni Virginianae (Br.), 20 p.c. + alcohol 62.5 p.c., finally add glycerin 10 p.c., dose, 3ss-1 (2-4 cc.).

Properties

Sedative, pectoral, aromatic bitter tonic, astringent; increases appetite, digestion. Volatile oil -- local stimulant on alimentary canal like cascarilla, serpentaria, etc. Hydrocyanic acid -- sedative, nervine, large doses decrease heart action. Tannin is astringent.

Uses

Consumption, cough, bronchitis, scrofula, heart palpitation, stomach atony, dyspepsia, hectic fever, debility; cold infusion in ophthalmia. It is much inferior to cinchona in intermittents.