SECTION 7.] 



ORDINARY LEAVES. 



59 



becomes thrice pinnate, or tripinnate, as iu many Acacias. The first divi- 

 sions are called Finnce ; the others, Pinnules ; and the last, or little blades 

 themselves, Leajlets. 



155. So the palmate leaf, if again 

 compounded in the same way, be- 

 comes twice palmate, or, as we say 

 when the divisions are in threes, 

 twice ternate (in Latin form biter- 

 nate') ; if a third time compounded, 

 thrice ternate or triternate. But 

 if the division goes still further, 

 or if the degree is variable, we 

 simply say that the leaf is decom- 

 pound ; either palmately or pin- 

 uately decompound, as the case 

 may be. Thus, Fig. 161 repre- 

 sents a four times ternately com- 

 pound (in other words a tcrnatelij 

 decompound) leaf of a common 

 Meadow Rue. 



156. When the botanist, in de- 

 scribing leaves, wishes to express 

 the number of the leaflets, he 

 may use terms Uke these : — 



Unifoliolate, for a compound 

 leaf of a single leaflet ; from the 

 Latin unum, one, and foliolum, . leo 



leaflet. 



BifoUolate, of two leaflets, from the Latin his, twice, a.nd foliolum, leaflet. 

 Trifoliolate (or ternate), of three leaf- 

 lets, as the Clover ; and so on. 



Palmatelj/ bifoliolute, trifoliolate, 

 quadrifoliatcy plurifoliolate (of several 

 leaflets), etc. : or else 



Pinnatelt/ bi-, tri-, quadri-, or pluri- 

 foliolate (that is, of two, tiiree, four, 

 five, or several leaflets), as the case 

 may be: these are terse ways of de- 

 noting in single phrases both the num- 

 ber of leaflets and the kind of com- 

 pounding, 

 certain peculiarities in structure, the 



157. 

 folio wi 



10.1 



Of foliage-leaves 

 g may be nnted : 



havinf 



Fig. 160. A twice-piiinatL" (.ibrnptly) leaf m the Honey-Locust. 

 Fig. 161. Ternately decompound leaf of Mv-ddow Rue. 



