Apocynum Androsaemifolium, Dog's Bane.
This is a branching perennial plant, found from Canada to Carolina about the sides offences and the borders of woods. It has a peculiarly neat aspect derived from its smoothness, its leafless and coloured stalk, bushy top and delicate flowers. Like the other American species, it is a lactescent plant, with a fibrous bark. It attains its flowering period in June and July.
The genus Apocynum has a bell-shaped corolla; a nectary of five corpuscles surrounding the germ; anthers adhering to the stigma by the middle; follicles tzvo; seeds with down.
The present species is glabrous, its stem erect and branching; cymes lateral and terminal i corolla spreading.
Class Pentandria, order Digynia; natural orders Contortae, Linnaeus; Apocinae, Jussieu.
The Apocynum Androsaemifolium grows often to the height of five or six feet, though its common elevation is three or four. Its stalk is smooth, simple below, branching repeatedly at top, red on the side exposed to the sun. Leaves opposite, smooth on both sides, paler beneath, ovate, acute, on short petioles. The flowers grow in nodding cymes from the ends of the branches and axils of the upper leaves, furnished with minute acute bractes. Calyx five-cleft, acute, much shorter than the corolla. Corolla white tinged with red, monopetalous, campanulate, with five acute, spreading segments. Stamens five, with very short filaments, and counivent, oblong arrowshaped anthers, cohering with the stigma about their middle. The nectary consists of five oblong glandular bodies alternating with the stamens. Germs two, ovate, concealed by the anthers. Stigma thick, roundish, agglutinated to the anthers. The fruit is a pair of slender linear-lanceolate follicles, containing numerous imbricated seeds each crowned with a long pappus or down, and attached to a slender central receptacle.
Every part of the Apocynum when wounded emits copiously a milky juice. When chewed, the root communicates an unpleasant and intensely bitter taste. It exhibits, when dry, the following chemical phenomena.
If a solution in ether be mixed with alcohol, the alcohol, though not turbid at first, becomes so when the ether evaporates. An aqueous infusion or decoction is of a deep red colour and intensely bitter. A solution in alcohol is nearly destitute of colour, but retains the whole bitterness of the plant, and is not disturbed by the addition of water. When submitted to distillation a slight oily film floats on the surface of water in the receiver.
From these facts we may conclude that the Apocynum contains, 1. A bitter extractive principle. 2. A colouring principle soluble in water and not in alcohol. 3. Caoutchouc. 4. A volatile oil.
In various parts of the Eastern States this plant has been shewn to me by country practitioners under the name of Ipecac. This name is applied to it from its power of acting on the stomach in the same manner as the Brazilian emetic. Several physicians, among whom is Dr. Richardson of Medway, inform me that they have found about thirty grains of the root to evacuate the contents of the stomach as effectually as two thirds the quantity of Ipecacuanha. In my own trials it has appeared to me much less powerful than the latter substance, and although it produces vomiting, yet this power is diminished by keeping, and appears to be eventually destroyed by age. When used for the purpose of an emetic, the recently powdered root should be employed.
The sensible and chemical qualities of this root seem to promise a good effect when given in small doses as a tonic medicine to the stomach. My observations on this subject may hereafter be more mature. (See Appendix.) We have certainly very few indigenous vegetables which exceed the Apocynum in bitterness. Perhaps its emetic property when given in large doses may be owing to this quality. Most bitter vegetables produce vomiting when administered in large quantities.
Kalm observes in his travels in North America, that in some parts of the country this plant was suspected of poisonous properties like those of the Rhus vernix. The country people informed him that the milky juice rubbed on the hands produced blistering in many persons, and that some were affected in the same way even by the effluvium of the plant.
I know of no other authority than that stated above for the existence of such a property in the Apocynum. The plant is common and well known in Massachusetts, yet I have never heard it suspected of deleterious properties.
The flowers of the Apocynum have a power of catching flies and small insects which was ascribed by Dr. Darwin to an irritability in the internal organs. Mr. Curtis in the Botanical magazine, has considered this subject at large, and ascribes the property to a more rational cause. In consequence of the close convergency of the anthers and their adhesion to the stigma, a narrow fissure or slit exists, which becomes more contracted near the top. The insect in search of the honey at the bottom of the flower, inserts his proboscis between the stamens into the cavity within them. In extricating it from this situation the proboscis is sometimes caught in the fissure, and in proportion to the efforts made by the insect to escape it becomes more closely wedged in the upper part of the slit, so that its deliverance by its own powers becomes at length impracticable. Mosquitoes, gnats, and small flies are frequently found dead in this confinement.
Apocynum androsaemifolium, Lin. Sp. pl.
Curtis, Botanical Magazine, t. 280.
Darwin, Botanic Garden, ii. 182.
Michaux, Flora, i. 121.
Pursh, i. 179.
Kalm, Travels, iii. 26.