The stem or root-crown of Savanilla rhatany is never so knotty and irregular as that of the Peruvian drug, nor are the roots so long or so thick. Separate pieces of root of sinuous form, 4 to 6 inches long and ²/₁₀ to ³/₁₀ of an inch thick are most frequent. The drug is moreover well distinguished by its dull purplish brown colour, its thick smooth bark marked with longitudinal furrows, and here and there with deep transverse cracks, and by the bark not easily splitting off as it does in common rhatany.
The anatomical difference depends chiefly upon the more abundant development of the bark which in thickness is ⅓ to ¼ the diameter of the wood. In Peruvian rhatany the cortical layer attains only ⅙ to ⅛ of the diameter of the woody column. The greater firmness of the suberous coat in Savanilla rhatany is due to its cells being densely filled with colouring matter.
Savanilla rhatany differs from the Peruvian root in its tannic matter. This becomes evident by shaking the powdered root (or bark) with water and iron reduced by hydrogen. The liquid filtered from the Savanilla sort and diluted with distilled water exhibits an intense violet colour, that from Peruvian rhatany a dingy brown; the latter turns light red by alkalis. Thin sections of the Peruvian root assume a greyish hue when moistened with a ferrous salt; Savanilla root by a similar treatment displays the above violet colour. The Savanilla root is richer in soluble matter and from the greater development of its bark may deserve to be preferred for medicinal use.
In the English market, Savanilla root is of less frequent occurrence than that of Pará.
A kind of rhatany attributed to Krameria secundiflora DC., a herbaceous plant of Mexico, Texas and Arkansas, was furnished to Berg in 1854, but has not been in commerce. Its anatomical structure has been described by Berg.[338]
GUTTIFERÆ.
CAMBOGIA.
Gummi Gambogia, Gummi Gutti; Gamboge; F. Gomme Gutte; G. Gutti, Gummigutt.
Botanical Origin—Garcinia Morella Desrousseaux, var. β. pedicellata, a diœcious tree,[339] with handsome laurel-like foliage and small yellow flowers, found in Camboja, Siam (province of Chantibun and the islands on the east coast of the gulf of Siam), and in the southern parts of Cochin China. It was introduced about thirty years ago into Singapore where several specimens are still thriving (1873) on the estate of Dr. Jamie. The finest is now a tree of 20 feet high, with a trunk a foot in diameter, and a thick, spreading head of foliage.
G. Morella Desr.—The typical form of this tree having sessile male flowers grows in moist forests of Southern India and Ceylon, and is capable of affording good gamboge.