CHAPTER XVI 

 LIFE HISTORY OF A LIVERWORT 



192. Habitat. The group of plants ranking next below 

 the mosses in the scale of life 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. Anthoceros 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. fimbriatus) 

 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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