EUPHORBIACEÆ.
EUPHORBIUM.
Euphorbium, Gum Euphorbium; F. Gomme-résine d’Euphorbe; G. Euphorbium.
Botanical Origin—Euphorbia resinifera Berg, a leafless, glaucous, perennial plant resembling a cactus, and attaining 6 or more feet in height. Its stems are ascending, fleshy and quadrangular, each side measuring about an inch. The angles of the stem are furnished at intervals with pairs of divergent, horizontal, straight spines about ¼ of an inch long, and confluent at the base into ovate, subtriangular discs. These spines represent stipules: above each pair of them is a depression, indicating a leaf-bud. The inflorescence is arranged at the summits of the branches, on stalks each bearing three flowers, the two outer of which are supported on pedicels. The fruit is tricoccous, ³/₁₀ of an inch wide, with each carpel slightly compressed and keeled.[2070]
The plant is a native of Morocco, growing on the lower slopes of the Atlas in the southern province of Suse. Dr. Hooker and his fellow-travellers met with it in 1870 at Netifa and Imsfuia,[2071] south-east of the city of Morocco, which appears to be its westward limit.
History—Euphorbium was known to the ancients. Dioscorides[2072] and Pliny[2073] both describe its collection on Mount Atlas in Africa, and notice its extreme acridity. According to the latter writer, the drug received its name in honour of Euphorbus, physician to Juba II., king of Mauritania. This monarch, who after a long reign died about a.d. 18, was distinguished for his literary attainments, and was the author of several books[2074] which included treatises on opium and euphorbium. The latter work was apparently extant in the time of Pliny.
Euphorbium is mentioned by numerous other early writers on medicine, as Rufus Ephesius, who probably flourished during the reign of Trajan, by Galen in the 2nd century, and by Vindicianus and Oribasius in the 4th. Aëtius and Paulus Ægineta, who lived respectively in the 6th and 7th centuries, were likewise acquainted with it; and it was also known to the Arabian school of medicine. In describing the route from Aghmat to Fez, El-Bekri[2075] of Granada, in 1068, mentioned the numerous plants “El-forbioun” growing in the country of the Beni Ouareth, a tribe of the Sanhadja; the author noticed the spiny herbaceous stems of the shrub abounding in the purgative milky juice.
Höst[2076] (1760-1768) stated that the plant, which he also correctly compared with Opuntia, is growing near Agader, south of Mogador.
The plant yielding euphorbium was further described at the beginning of the present century by an English merchant named Jackson, who had resided many years in Morocco. From the figures he published,[2077] the species was doubtfully identified with Euphorbia canariensis L., a large cactus-like shrub, with quadrangular or hexagonal stems, abounding on scorched and arid rocks in the Canary Islands.
In the year 1849 it was pointed out in the (Admiralty) Manual of Scientific Enquiry, that the stems of which fragrants are found in commercial euphorbium, do not agree with those of E. canariensis. Berg carried the comparison further, and finally from the fragments in question drew up a botanical description, which with an excellent figure he published[2078] as Euphorbia resinifera. The correctness of his observations has been fully justified by specimens[2079] which were transmitted to the Royal Gardens, Kew, in 1870, and now form flourishing plants.