Origin. According to O. Stapf1), mana-grass is in all probability the mother plant of the citronella-grass. There are two varieties, the Cymbopogon Nardus var. Linnaei (typicus) and C. Nardus var. confertiflorus. The native of Ceylon makes further distinctions, all of which have been referred by Stapf to the two varieties mentioned. However, the oils of these two grasses have no peculiar characteristics. Both vary irregularly in yield and in properties, which differences are probably due to differences in cultivation, fertilization, and the season in which the oils are distilled.
Production. In Bandarawela, Ceylon, J. F. jowitt1) has made experiments as to the cultivation and distillation of both varieties. The oils obtained were examined in the Imperial Institute, London, by S. S. Pickles1). The yield fluctuated between 0,06 and 0,45 p. c, the grasses distilled in May giving a specially low yield, those distilled in subsequent months mostly higher yields.
Properties. 1. Oil from C. Nardus var. Linnsaei: d15o 0,894 to 0,926; aD + 4°54' to - 6°32'; total geraniol 43,5 to 64,7p.c. 2. Oil from C Nardus var. confertiflorus: d15o 0,900 to 0,929; aD + 12°12' to - 2° 11'; total geraniol 39,1 to 64, 2p.c.
These oils were light to dark yellow in color. With few exceptions their odor was agreeably citronella-like, but mostly somewhat pungent. With 1 to 1,4 vol. of 80 p.c. alcohol they yielded clear solutions, which became more or less distinctly opalescent upon the addition of 10 vols, of solvent. In two cases a light turbidity resulted, but in one case only the solution remained clear upon dilution. In addition to the "total geraniol" content, that of geraniol alone was determined separately according to the phthalic acid anhydride method. These determinations revealed fluctuations as great as were observed in the other properties of the two grass oils.
1) J. F. Jowitt, Cymbopogon Grass Oils in Ceylon. Circulars and Agricultural Journal of the Royal Botanic Gardens, Ceylon. 5 (1910), No. 12, p. 115. Comp. also S. S. Pickles, Bull. Imp. Inst. 8 (1910), 144.