Ramalina tayloriana, a lichen growing on sandal-wood trees is considered to produce adverse effect on the trees both by physical injury caused by the hold fasts and by means of its toxic components, usnic and sekikaic acids which are found to be toxic to fish.Roccella montagnei appears to have no such effect. It is found to be rich in β-carotene. Convenient methods of separating the various components of these lichens are described.

Two lichens are found on the sandal trees of Coorg which do not suffer adverse effects on this account.Parmelia tinctorum was earlier reported to contain atranorin and lecanoric acid; considerable amounts of nor-stictic acid are now isolated from it.Usnea japonica is reported for the first time in India. Besides usnic and stictic acids already known in this source, barbatolic acid also has now been found to be present in it.

A yellow lichen accompanyingRamalina tayloriana has been identified asTeloschistes flavicans. Besides physcion and a colourless substance, another orange coloured compound melting at 229–30° and having the formula C₁₆H₁₂O₆ is now isolated. It is designated ‘Teloschistin’. It resembles physcion closely and its constitution is established as 4∶5-dihydroxy-7-methoxy-2-hydroxymethyl anthraquinone (ω-hydroxy physcion).

Chromic acid oxidation of teloschistin triacetate yields 4:5-diacetyl-7-O-methylemodic acid. The identity of this acid has been established by comparison with a sample obtained from physcion diacetate by oxidation and by its conversion into 7-O-methylemodic acid and its methyl ester on treatment with methyl alcoholic potash and methyl alcoholic sulphuric acid respectively. The location of the methoxyl group in teloschistin at position 7 has thus been rigidly established. The reduction of teloschistin to its anthranol and its regeneration from this compound are described.