Pilocarpus Selloanus[447] Engler, occurring in Southern Brazil and Paraguay, appears to be not considerably different from P. pennatifolius.
History—Piso[448] recommended an infusion made with Ipecacuanha and Jaborandi. Plumier,[449] who also mentioned this, figured under the name of Jaborandi two plants of the order Piperaceæ. The introduction of the leaves of Pilocarpus pennatifolius into medical use is due to Dr. Coutinho of Pernambuco, 1874. The plant has been cultivated in European greenhouses since about the year 1847; we have repeatedly seen it flowering at Strassburg. Baillon in 1875 showed the fragments of Jaborandi as supplied by Coutinho to belong to P. pennatifolius, which had been described in 1852 by Lemaire. Holmes (1875) in examining the drug as imported from Pernambuco came to the same conclusion.
Description—The leaves of the species under examination are long-stalked, imparipennate, the opposite leaflets in 2 to 5, in cultivated plants most commonly in 2 pairs, the terminal one longer stalked, while the others are provided with a petiole attaining 1½ inch in length or remaining much shorter. The whole leaf is frequently 1½ feet long, the leaflets being often as much as 5 inches long by 2 inches wide. The latter are entire oblong, tapering or rounded at the base, tapering or obtuse or even emarginate at the apex. The leaflets are coriaceous, with a slightly revolute margin and a prominent midrib below. In transmitted light they show very numerous pellucid oil-glands.
The taste of the leaves of Pilocarpus is at first bitterish and aromatic; they subsequently produce a tingling sensation in the mouth and an abundant flow of saliva.
Microscopic Structure[450]—The oil-glands consist of large cells of the same structure as those occurring generally in the leaves of Rutaceæ, Aurantiaceæ, Myrtaceæ. In Pilocarpus they are largely distributed in the tissue covered on both sides of the leaf by the epidermis; the oil-cells are also abundantly met with in the petiole and in the bark of the stems and branches.
Chemical Composition—The active principle of Jaborandi is the alkaloid Pilocarpine, C₂₃H₃₅N₄O₄ + 4OH₂, discovered in 1875 by Hardy. It is an amorphous soft mass, but yielding crystallized salts, among which the hydrochlorate and the nitrate are now more frequently used than the drug itself. The leaves afford about ½ per cent. of the nitrate.
The occurrence of another peculiar alkaloid in Pilocarpus has been asserted, but not ultimately proved.
The leaves contain about ½ per cent. of essential oil, the prevailing constituent of it being a dextrogyrate terpene, C₁₀H₁₆, boiling at 178°, which forms a crystallized compound C₁₀H₁₆ + 2HCl melting at 49°·5 C.
Uses—Pilocarpine being a powerful diaphoretic and sialagogue, the leaves of Jaborandi are used to some extent in pharmaceutical preparations.
Other Kinds of Jaborandi—This name, as above stated, has originally been given to plants of the order Piperaceæ, some of which are still known in Brazil under the name Jaborandi. The following may be quoted as being used at least in that country: Serronia Jaborandi[451] Gaudichaud, Piper reticulatum L. (Enckea Miquel), Piper citrifolium Lamarck (Steffensia Kunth), Piper nodulosum Link, Artanthe mollicoma Miq.