168 GUIDE TO THE STUDY OF LICHENS. 



By many collectors this plant is designated as U» 

 harbata. It occurs on trees in proximity to U. barbata. 



2, Usnea barbata. Thallus medium, much branched ; 

 branches comparatively rigid, transversely fissured, 

 especially the larger main branches, greenish-gray. 

 Apothecia numerous, very large, bearing filiform 

 branches. Disk somewhat concave, light-brown color. 

 Spores typical, 8/x X 5/^* 



This is the " beard-moss " or " tree-moss " of poets 

 — the " idle moss " of Shakespeare. It is a cosmo- 

 politan plant; it occurs plentifully in the arctic 

 regions as well as in the tropics. In some coun- 

 tries it is eaten by wild animals or is collected and 

 preserved as fodder for domestic animals. Bertram 

 states that the Pennsylvanians prepared from it an 

 orange dye, and Humboldt states that the South Ameri- 

 cans used it for dyeing purposes. In the past ages it 

 enjoyed an extensive use as a remedial agent. It was 

 used as an astrigent, tonic, diuretic ; it was highly 

 recommended for whooping-cough, and as an anodyne. 

 It formed the basis of hair-powders and perfumes and 

 was thought serviceable in the preparation of explo- 

 sives. Boiled in beer it was said to cure catarrh 

 and dropsy. The Laplanders used it in the treatment 

 of scald head, and scrofula of children. 



3. Usnea longissima. Thallus much elongated, 

 branched, lobes somewhat flattened, greenish-gray. 

 Apothecia rare or wanting. Spores typical, 9/>(, X 5/x. 



The thallus is much longer than in JJ. barbata, and 

 also more slender and pendulous. It occurs mostly 

 upon trees on high mountains. 



