THE LEAVES OF VASCULAR PLANTS. 265 



plane, as the nerves of peltinerved leaves — for example, 

 in Sterculia foetida ; — Pedate, when their leaflets arise 

 from the inner border of two principal nerves which 

 diverge from the top of a common petiole ; but it is 

 doubtful if true pedate leaves exist, and the small num- 

 ber to which this name has been given, appear to be 

 simple pedatisected ones. 



Wlien the partial leaflets are distributed either along 

 a common petiole, or at its extremity, after one of the 

 systems w^hich I have pointed out, and when they them- 

 selves bear leaflets " distributed according to the same 

 system, this disposition is easily and clearly expressed 

 by saying that the leaf is Bipinnate (PI. 7, fig. 2, 3), 

 or Bipalmate (PL 1 1, fig. 3) ; and we should say, in the 

 same manner, that it is Bipeltate or Bipedate, if 

 either of them happen to be found, which is not yet the 

 case. We say, after the same principle, that the leaf is 

 Tripalmate, &c. 



When it is wished to express the number of the 

 leaflets, it is stated by a paraphrase, or by the terms 

 Unifoliate, Bifoliate, and Multifoliate. This is 

 very important in palmate or peltate leaves. Neverthe- 

 less, botanists often manifest a want of precision in this 

 respect, and here and there employ the term of leaves 

 instead of leaflets, or even of segments ; thus, AnthyUis 

 tetraphylla ought to have been called A. quadrifoliata ; 

 Marsilea quadri folia is, truly, M. quadrisecta ; Sophora 

 bifolia and Cassia diphylla ought to have been named 

 hifoliolata, &c. 



As for pinnate leaves, the leaflets are most frequently 

 opposite one another, and then they are counted by 

 Pairs (jugum) ; thus, one says of a pinnate leaf, that 

 it has one pair (unijugum), or two pair, &c. When the 

 leaflets are alternate, we can also, in most cases, recog- 

 nise the primitive pairs, and continue to say that they 



