PLANTS. 367 



and slender, lanceolate leaves ; capsule yellow and purp- 

 lish red. Grows in moist grounds, mostly in damp 

 woods. Used for making brushes, and, when found 

 abundantly, for filling beds. 2. 



SECOND SUB-CLASS. UNLEAVED CELLULAR PLANTS. 

 THALLOPHYTES. 



These vegetables, called Thallophytes, from their pe- 

 culiar conformation, never exhibit any distinction of 

 root, stem or foliage, axis or leaves, and are without 

 any visible indication of the fructifying principle. The 

 first of this class is the 



SEVENTY-THIRD FAMILY. LICHENS, which are, of 

 all vegetable structures, the most widely spread. Con- 

 sisting of flat expansions, rather crustaceous than foliace- 

 ous, they do not, like other plants, require earth on 

 which to root or draw subsistence, but merely a place 

 whereon to fasten by their lower surface, while by the 

 upper they draw their nourishment directly from the 

 air. They grow on every brick, stone, or naked rock, 

 upon trunks of trees in endless variety, and are ever 

 enduring. The most conspicuous of the race is 



The Iceland Moss (Cetraria islandica), grayish-green 

 or brown, stands upright, spotted red on the lower part. 

 Leaves irregularly lobed and many -cleft ; fruit (or what 

 is supposed to be such) flat and of a chestnut brown. 

 Grows on the ground in dry, mountainous, open places, 

 also in pine forests ; found in very cold countries, as Ice- 

 land, Lapland, etc. Contains a great deal of mucilage, 

 starch, and a bitter principle probably tonic ; forms the 

 chief article of nourishment of rein-deer, and is recom- 



