ECONOMIC USES OF LICHENS — LLANO 419 



loriana^ had penetrated deeply into the viable tissues of its subtrate 

 causing apparent physical injury. On analysis, this lichen gave 

 d-usnic and sekikaic acids which had a proved toxic effect on fish 

 used in experimentation. The suggestion is advanced that the deep 

 penetration of the lichen base into the viable sandalwood tissue may 

 have resulted not only in physical injury but in a phytocidal effect. 

 Wellborn (13) suggested that some leaf spots of the coffee plant may 

 be caused by a lichen, and the classical research of Ward (21) on 

 Strigula comfplanta Mont, illustrates the undeniable harmful effect of 

 a lichen ephiphyte on a crop plant. Leaf lichens are common on ever- 

 greens, deciduous trees, and bushes in the sub-Tropics and Tropics, but 

 unless the leaves of such phanerogams have a commercial application, 

 as tea leaves, there is no economic loss involved. Foresters in some 

 parts of Europe recommend scraping lichens from trees, but there is 

 little experimental proof that lichens ephiphytically attached to the 

 bark, branches, and twigs of trees are the cause of damage. Howbeit, 

 the whole problem of whether lichens injure the trees on which they 

 are fastened cannot be solved, as Elias Fries once remarked, "by mere 

 denial." 



DYEING INSTRUCTIONS FOR HOME USE (10) 



Parmelia saxatilis. — The Swedish country people call this the dye- 

 lichen or stone-moss. It occurs abundantly on rocks and stones as 

 rugose gray-brown patches, and should be collected after rain while 

 the air is still moist, for it is firmly attached to the stones and will 

 crumble if removed in dry air. It is most easily separated from the 

 stones by an ordinary table knife, and if it is to be preserved it must 

 be carefully dried before being packed in bags or boxes. Before use 

 it should be finely crushed. The following colors may be obtained by 

 varying the dyeing treatment : 



1. Light yellow-brown. — Place 1 kilogram (2.2 pounds) of finely 

 crumbled dye-lichen in a copper kettle containing a large quantity 

 of water. Place 250 grams '^ of unmordanted (raw) yarn in this 

 solution, boiling and stirring the yarn for 1/2 to 2 hours, depending on 

 the desired shade of color. The best method of stirring the yarn is to 

 wind it around sticks so as to avoid cloudy or uneven dyeing. Wlien 

 the process is completed, the yarn should be washed thoroughly in 

 several changes of clean water, after which it may be hung up to dry, 

 making sure that the skein hangs freely. 



2. Dark brown. — The lichen is crumbled and placed in layers with 

 wool or yarn in an iron kettle. The yarn should be wet when put 

 down, and after addition of cool water in sufficient quantities to cover 

 the mass, several hours should lapse before boiling. Boiling must be 

 slow and regular with constant stirring for 2 to 6 hours. If a very 



1 ounce = 28.35 grams; 1 pound = 0.45 kilogram. 



