2 HEPATIC^.. 



The foliose species have a distinct stem with leaves; these 

 stems are either cylindrical, frontally or laterally compressed, and 

 various in texture, some being almost ligneous, others loosely 

 cellulose. In position they are either erect, depressed, procumbent, 

 or pendant ; they are either simple or slightly branched, pinnate 

 or bipinnate ; their ramification either lateral or postical ; a cross- 

 section of the stem discloses great variety in the size, arrangement, 



and texture of the cells, which affords good characters in the 

 determination of species. 



EooTLETS. — Some species are almost destitute of these; in 

 others they are often very abundant, proceeding from the postical 

 side of the stem, from the base of the stipules, or very rarely from 

 the underside of the postical lobe of some species. They are 

 usually short, simple or rarely forked, unicellular fibres, sparingly 

 dispersed or closely clothing the postical side of the stem. 



In one genus only (Biccia) they are papillose within ; all the 

 others are smooth, semi-transparent or pellucid, sometimes dirty 

 white, claret or purple coloured. 



Leaves. — The insertion, position, and shape of the leaves are 

 fully described with each species. 



The above diagram illustrates the terms used with reference 

 to their position on the stem. 



Erect, making an angle with the stem of about 10°. 



