CHAPTER XVI 



LIFE HISTORY OF A LIVERWORT 



192. Habitat. — The group of plants ranking next below 

 the mosses in the scale of Hfe is the liverworts (Hepaticse). 

 They are widely distributed over the earth's surface; 

 being found in a wide climatic range, but usually in moist 

 situations. Some forms (e.g., Riccia natans) may grow 

 floating on the surface of water, others {e.g., Riccia fluitans) 



Fig. 152. — Anlhoceros fusiformis. Portion of lamellate, cristate thallus, 

 which easily retains water. (After M. A. Howe.) 



submerged; but, as in mosses, no salt-water forms have 

 been found. A few species grow on other plants {epi- 

 phytic), or in other situations where the water supply 

 may at times fall very low. Such forms have various 

 contrivances which serve to retain water. Thus, some 

 species of Anthoceros {e.g., A. fusiformis, A. fimhriatus) 

 possess crisped lobes, forming a fringe around the margin 

 which helps the plant to retain water (Figs. 152 and 

 153). In another species {A. punctatus), water is retained 



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