Capsulæ Hibisci esculenti; Uëhka, Okro, Okra, Bendi-kai[375]; F. Gombo (in the French Colonies).
Botanical Origin—Hibiscus esculentus L. (Abelmoschus esculentus Guill. et Perr.) an herbaceous annual plant 2 to 3 or even 10 feet high, indigenous to the Old World.[376] It has been found growing abundantly wild on the White Nile by Schweinfurth, and also in 1861 by Col. Grant in Unyoro, 2° N. lat., near the lake Victoria Nyanza, where it is known to the natives as Bameea.
The plant is now largely cultivated in several varieties in all tropical countries.
History—The Spanish Moors appear to have been well acquainted with Hibiscus esculentus, which was known to them by the same name that it has in Persian at the present day—Bámiyah. Abul Abbas el-Nebáti, a native of Seville learned in plants, who visited Egypt in a.d. 1216, describes[377] in unmistakeable terms the form of the plant, its seeds and fruit, which last he remarks is eaten when young and tender with meat by the Egyptians. The plant was figured among Egyptian plants in 1592 by Prosper Alpinus,[378] who mentions its uses as an external emollient.
The powdered fruits as imported from Arabia Felix were known for some time (about the year 1848) in Europe as Nafé of the Arabs. They are noticed in the present work from the circumstance that they have a place in the Pharmacopœia of India.
Description—The fruit is a thin capsule, 4 to 6 or more inches long and about an inch in diameter, oblong, pointed, with 5 to 7 ridges corresponding to the valves and cells, each of which latter contains a single row of round seeds. It is covered with rough hairs and is green or purplish when fresh; it has a slightly sweet mucilaginous taste and a weak herbaceous odour. Like many other plants of the order, Hibiscus esculentus abounds in all its parts with insipid mucilage.
Microscopic Structure—A characteristic part for microscopic examination are the hairs of the fruit. They exhibit at the base one large cell, but their elongated and often slightly curved end is built up at a considerable number of small cells, without any solid contents. The middle and outer zone of the pericarp shows enormous holes filled up with colourless mucilage. In polarized light it is easily seen to be composed of successive layers.
Chemical Composition—It is probable that the fruits contain the same mucilage as Althæa, but we have had no opportunity of investigating the fact. Landrin[379] says it turns violet with iodine and yields no mucic acid when treated with nitric acid. Popp, who examined the green fruits in Egypt, states[380] that they abound in pectin, starch and mucilage. He found that when dried they afforded 2 to 2·4 per cent. of nitrogen, and an ash rich in salts of lime, potash and magnesia. The ripe seeds gave 2·4-2·5 per cent. of nitrogen; their ash 24 per cent. of phosphoric acid.
Uses—The fresh or dried, unripe fruits are used in tropical countries as a demulcent like marshmallow, or as an emollient poultice, for which latter purpose the leaves may also be employed. They are more important from an economic point of view, being much employed for thickening soups or eaten boiled as a vegetable. The root has been recommended as a substitute for that of Althæa.[381] The stems of the plant yield a good fibre.