78. Curcuma angustifolia, Roxburgh.—The Narrow-leaved Turmeric.
Sex. Syst. Monandria, Monogynia.
(Faecula tuberis. East Indian Arrow-root, Offic.)
History.—This plant was found by H. T. Colebrook, Esq., in the forests extending from the hanks of the Sona to Nagpore, and was by him introduced into the Botanic garden at Calcutta. [Roxburgh, Fl. Indica, vol. i. p. 31.]
Botany. Gen. Char.—Vide Curcuma longa.
Sp. Char.—Bulb oblong, with pale, oblong, pendulous tubers only. Leaves stalked, narrow lanceolate. Flowers longer than the bracts.
Hab.—East Indies; from the banks of the Sona to Nagpore (Roxburgh). Also in abundance on the Malabar coast (Ainslie).
Extraction of the Fecula.—From the tubers of several species of Curcuma is obtained, in the East Indies, a fecula called tikor.
According to Dr. Roxburgh, [Roxburgh, Asiatic Researches, vol. xi. p. 218; also, Fl. Indica, vol. i. p. 21.] the biennial roots of the genus Curcuma consist of what he calls bulbs, tubers, and fibres. The bulbs are formed during the first year, and support the aerial parts of the plants; hence they may be termed phyllophorous receptacles. From these bulbs issue the palmate tubers, and chiefly the fibres or genuine roots; the latter issuing from the lower part of the bulbs. Some of the fibres end in a single oblong, pearl-coloured, solid tuber. From these tubers, and from no other parts, the natives of various parts of India obtain starch.
At Bhagulpore this is procured from C. leucorrhiza. "The root is dug up, and rubbed on a stone, or beat in a mortar, and afterwards rubbed in water with the hand, and strained through a cloth; the fecula having subsided, the water is poured off, and the Tikor (fecula) dried for use." [Roxburgh, Fl. Indica, vol. i. p. 30.]
At Travancore, and also, according to Bennett, [Ceylon and its Capabilities, p. 151.] at Bombay, from the C. angustifolia. "So much of it has been made of late years on the Malabar coast, where the plant grows in abundance, that it has become a considerable object in trade, and is much prized in England." [Ainslie, Mat. Indica, vol. i. p. 19, 1826.]
C. rubescens is another species which also yields the fecula called tikor.
Description.—Curcuma starch (amylum curcuma) or tikor is imported from the East Indies under the name of East India arrow-root. But as this name is also applied to the starch of Maranta arundinacea, cultivated in the East Indies, I have thought it advisable to distinguish it by the name of "Curcuma starch."
Two kinds of Curcuma starch are imported from Calcutta; one white, the other buff-coloured.
α. White tikor, or curcuma starch, or white East Indian arrow-root, is a fine white powder, readily distinguishable, both by the eye and the touch, from West Indian arrow-root. To the eye it somewhat resembles a finely-powdered salt (as bicarbonate of soda or Rochelle salt). When pinched or pressed by the fingers, it wants the firmness so characteristic of West Indian arrow-root, and it does not crepitate to the same extent when rubbed between the fingers.
Examined by the microscope, the particles of this starch are found to be transparent flattened disks of about the 1/3333d of an inch in thickness. [The particles of plantain-starch, like those of curcuma-starch, are flat disks (see ante, p. 223).] Their shape is ovate, or oblong-ovate, with a very short neck or nipple-like projection at one extremity, where is situated the part called the hilum. The largest are about 1/370th of an inch in length, and 1/770th of an inch in breadth. [The following measurements, in parts of an English inch, of the particles of East India arrow-root, were made for me by Mr. George Jackson:—Particles. Length. Breadth. 1. 0.0027. 0.0013. 2. 0.0029. 0.0011. 3*. 0.0022. 0.0011. 4*. 0.0017. 0.0010. 5*. 0.0013. 0.0008. 6. 0.0012. 0.0007. 7. 0.0007. 0.0004. Average thickness. 0.0003.]
On account of their flatness they have but little lateral shading, except when viewed edgewise. The hilum or nucleus is placed at the narrow extremity—is circular, very small, and not very distinct. The rings (or rather portions of rings) are seen both on the flat surface and on the edges; they are numerous, close, and very fine.
β. Buff-coloured tikor, or curcuma starch; pale buff-coloured East Indian arrowroot.—In the form of powder, or of pulverulent masses, which are dirty or buffy white. Paddy husks, woody fibre, and various impurities, are intermixed.
To the microscope both kinds present the same appearance, from which it is probable that they are obtained from the same plant, but with unequal degrees of care. The particles of East Indian arrow-root are very unequal in size, but on the average are larger than those of West Indian arrow-root.
Composition.—Not ascertained, but doubtless analogous to that of other starches, viz. C12H10O10.
Effects and Uses.—Analogous to those of the West Indian starch. Its commercial value, however, is much below that of the latter. At Travancore, it forms a large portion of the diet of the inhabitants (Roxburgh).