SECTION 7.] 



ORDINARY LEAVES. 



59 



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

 sions are called Pinna; the others, Pinnules; and the lust, or little blades 

 themselves, Leaflets, 



] 55. So the palmate leal", if again 

 compounded in the same way, be- 

 comes twice palmate ) or, as we sav 

 when the divisions are ill threes, 

 twice ternate (in Latin form biter- 

 nate) ; if a third time compounded, 

 thrice ternate or triternate. Hut 

 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- 

 nately decompound, as the case 

 may be. Thus, Fig. 161 repre- 

 sents a four times ternately com- 

 pound (in other words a ternately 

 decompound) leaf of a common 

 Meadow Hue. 



156. When the botanist, in de- 

 scribing leaves, wishes to express 

 the number of the leaflets, he 

 may use terms like these : — 



Unifoliolate, for a compound 

 leaf of a single leaflet ; from the 

 Latin unum, one, and foliolum, 

 leaflet. 



Bifoliolate, of two leaflets, from the Latin bis, twice, andfoliolum, leaflet. 



Trifoliolate (or ternate), of three leaf- 

 lets, as the Clover ; and so on. 



Palmate!;/ bifoliolate, trifoliolate, 

 quadrifoliate, plurifoliolate (of several 

 leaflets), etc. : or else 



Pinnately bi-, tri- s quadri-, or pluri- 

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

 five, or several leaflets), as the case 

 may be: I hesc are terse ways of de- 

 noting in single phrases both the num- 

 ber of leaflets and the kind of eom- 



pounding. 

 L57« Of foliage-leaves having certain peculiarities in structure, the 



following may be noted : — 



Pio. 1'i 1 *. A twice-pinnate abruptly) leaf of the lloney-Locust. 

 Fig. 1G1. Ternately decompound leaf of Meadow Rue. 



