SOUDAN COFFEE.
(Parkia biglobosa.)
There are valuable plants on every continent. Civilized Europe no longer counts them. Mysterious Africa is no less largely and spontaneously favored with them than young America and the ancient territory of Asia.
The latter has given us the majority of the best fruits of our gardens. We have already shown how useful the butter tree (Butyrospermum Parkii) is in tropical Africa, and we also know how the gourou (Sterculia acuminata) is cultivated in the same regions. But that is not all, for the great family of Leguminosæ, whose numerous representatives encumber this continent, likewise furnishes the negro natives a food that is nearly as indispensable to them as the gourou or the products of the baobab—another valuable tree and certainly the most widely distributed one in torrid Africa. This leguminous tree, which is as yet but little known in the civilized world, has been named scientifically Parkia biglobosa by Bentham. The negroes give it various names, according to the tribe; among the Ouloffs, it is the houlle; among the Mandigues, naytay; in Cazamance (Nalon language), it is nayray; in Bornou, rounuo; in Haoussa, doroa; in Hant-fleure (Senegal), nayraytou. On the old mysterious continent it plays the same role that the algarobas do in young America. However, it is quite a common rule to find in the order Leguminosæ, and especially in the section Mimosæ, plants whose pods are edible. Examples of this fact are numerous. As regards the Mediterranean region, it suffices to cite the classic carob tree (Ceratonia siliqua), which also is of African nationality, but which is wanting in the warm region of this continent.
Throughout the tropical region of Africa, the aborigines love to consume the saccharine pulp and the seed contained in the pod of the houlle. Prepared in different ways, according to tribe and latitude, these two products constitute a valuable aliment. The pulp is consumed either just as it is or as a fermented beverage. As for the seeds, they serve, raw or roasted, for the production of a tea-like infusion (whence the name "Soudan coffee"), or, after fermentation in water, for making a national condiment, which in certain places is called kinda, and which is mixed with boiled rice or prepared meats. This preparation has in most cases a pasty form or the consistency of cohesive flour; but in order to render its carriage easier in certain of the African centers where the trade in it is brisk, it is compressed into tablets similar to those of our chocolate. As these two products are very little known in Europe, it has seemed to us that it would be of interest to give a description and chemical analysis of them. We shall say but little of the plant, which has sufficiently occupied botanists.
The houlle (Parkia biglobosa) is a large tree from 35 to 50 feet in height, with a gray bark, many branches, and large, elegant leaves. The latter are compound, bipinnate (Fig. 7), and have fifty pairs of leaflets, which are linear and obtuse and of a grayish green. The inflorescence is very pleasing to the eye. The flowers, say the authors of the Floræ Senegambiæ Tentamen, form balls of a dazzling red, contracted at the base, and resembling the pompons of our grenadiers (Fig. 8). The support of this latter consists only of male flowers. The fruit that succeeds these flowers is supported by a club-shaped receptacle. It consists of a large pod, which at maturity is 13 inches in length by 10 in width (Fig. 1). This pod is chocolate brown, quite smooth or slightly tubercular, and is swollen at the points where the seeds are situated. The pods are straight or slightly curved. The aborigines of Rio Nunez use the pods for poisoning the fishes that abound in the watercourses. We do not know what the nature of the toxic principle is that is contained in these hard pods, but we well know the nature of the yellowish pulp and of the seeds that entirely fill the pods.
Fig. 7.—PARKIA BIGLOBOSA.
Although the pulp forms a continuous whole, each seed easily separates from the following and carries with it a part of the pulp that surrounds it and that constitutes an independent mass (Fig. 2). This pulpy substance, formed entirely of oval cells filled with aleurone, consists of two distinct layers. The first, an external one of a beautiful yellow, is from 10 to 15 times bulkier than the internal one, which likewise is of a beautiful yellow.