LEAVES. 203 



lipinnate and tripinnate ; and into ternate, liternate, and 

 triternate^ &c. 



A pinnate (or winged) leaf, is one, the stem or foot-stalk 

 of which has several leaflets at each side, growing, at equal 

 distances, in pairs. (Fig. 141.) 



A lipinnate leaf is one in which the footstalk itself is 

 divided, and branches out into other footstalks, each of which 

 supports leaflets, corresponding in all their modifications to 

 those of the simply pinnate leaf. (Fig. 142.) 



A tripinnate leaf is of the same description as the above, 

 once more decompounded : the footstalk being lipinnate, and 

 supporting leaflets, as in the former modes. (Fig. 143.) 



The term ternate, with its compounds, indicates an analo- 

 gous arrangement. A ternate leaf is so called when the 

 footstalk supports three leaflets (Fig. 144) ; 



FIG. 143. FIG. 144. 



a Hternate leaf is when the common footstalk supports three 

 others, each of which supports three leaflets (fig. 145) ; and 

 a triternate leaf is only a farther decomposition of the above. 

 (Fig. 146.) 



Apinnatifidleaifis one which is cut transversely into several 

 oblong, parallel segments (fig. 147) ; and Hpinnatifid denotes 

 another decomposition of the same form. (Fig. 148.) 



As to position, leaves are either radical, that is, proceeding 

 from the crown, or radical plate ; or they are caulinar, borne 

 on the stem ; and either sessile or petiolate, that is, either 

 sitting or having footstalks. Sessile leaves are sometimes 

 vaginant, that is, sheathing, as in grasses ; or amplexicaule, 



