COMPOUND LEAVES. 



91 



the point of attachment of the two lateral 

 leaflets (Fig. 4G1). In the pinnate form 

 such a rhachis (Fig. 462a), although fre- 

 quently very short, does exist. In the 

 natural order, Leguminosae, the question 

 of whether a leaf is pinnately or pal- 

 mately trifoliolate is of fundamental im- 

 portance in classification. A three-parted 

 palmately compound or divided leaf is 

 called Teruate; a five-parted one Quinate, 

 a seven-parted one Septate. A palmatifid 

 (or palmate) leaf, with very narrow divis- 

 ions, is called Pedate (Fig. 464). If the 

 divisions of such a leaf are similarly com- 

 pound or divided, appropriate terms are 

 formed, such as Bi-ternate (Fig. 463), Tri- 

 ternate, and so on. Similarly named sub- 

 divisions of the pinnate form exist, the bi- 

 pinnate (Fig. 463a), tri-pinnate, and so 

 on. The primary leaflets of a pinnate leaf 

 are called Pinnae, secondary ones and 



those of higher rank. Pinnules. These 

 terms are also sometimes applied to the 

 similar divisions of piunatifid leaves. Just 

 as we have found that the number of pairs 

 of primary veins of the simple leaf is gen- 

 erally characteristic of the species, so we 

 find that the number of pairs of pinnae, 

 technically known as Jugae, is equally so. 

 This number, therefore, should always be 

 stated, the leaf being designated as Bi- 

 jugate, Tri-jugate, Multi-jugate and so 

 on. Two classes of pinnate leaves are 

 recognized, in accordance with their ter- 

 mination in a pair or a single terminal 

 leaflet. Those ending in a pair (Fig. 4G5) 

 are called Pari-pinnate, Even-pinnate, or 

 Equally-pinnate, the others (Fig. 466) 

 Impari-pinnate, Odd-pinnate or Un- 

 equally-pinnate. When the divisions of a 

 pinnate or a pinnatifid leaf are alternately 

 large and very small (Fig. 467), it ia called 



