XXXVI.—The colouring matter of Drosera Whittakeri

Edward H. Rennie
1887 Journal of the Chemical Society Transactions  
AMONG the many species of Drosera to be found in Australia, one, Drosera Whitta7ceri, which grows plentifully on the hills near Adelaide, is conspicuous in the spring-time by its pretty white flowerst resembling those of the white oxalis. This species is provided with a tuber, one apparently to each plant, which is found attached t o a straight stem at a depth of 3 or 4 inches. These tubers invariably consist of an inner solid but soft nucleus, full of reddish sap or juice, and an outer series
more » ... nd an outer series of easily detached thin and more or less dry layers of an almost black material. Between these layers is to be found small quantities of a brilliant red colouring matter, the amount varying in tubers of different size and age, but apparently more plentiful in the older plants. My attention was drawn to the plant by Professor Tate, of Adelaide University, and on iiiquiry I found that Mr. Francis, of this city, had extracted the colouring matter by means of carbon bisulphide, found that it was volatile, and that by its means beautiful tints could be produced on silk by the use of various mordants, but beyond that had not continued the investigation. A preliminary examinatioii having shown that the substance could be obtained in the crystalline condition, it was determined to further investigate it. The plant is easily obtainable in spring, but on the
doi:10.1039/ct8875100371 fatcat:7hzilanxubfj3c3t3etke6snu4