INTRODUCTION. 17 



then tlie middle secondary tooth of each of them usually 

 shows a clear tendency to take the forward or the patent 

 direction observable in the typical forms. 



The general and i)artial petioles are flat or furrowed on 

 their upper side and rounded below. Their under sides are 

 also furuished with more or less numerous prickles similar 

 to, but usually rather larger than, those fouud on the under 

 side of the midrib of the leaflets. 



In all the fruticose species the stipules are attached to 

 the petiole at some little distance from its insertion; but 

 herbaceous Ruhi have their stij^ules attached to the stem 

 itself In this respect It. saxatilis seems to connect these 

 gi-eat divisions, for the stipules of its barren stem are often 

 on the petioles, whilst those of the flowering shoot spring 

 from the stem itself 



The floioerhvj shoot gi'ows from buds formed in the axils 

 of the leaves of the barren stem of the preceding year; ex- 

 cepting in some of the Herhacei, where the stem is repre- 

 sented by a subterranean creeping rhizome, from which the 

 flowering shoots rise at intervals. Therefore the only difier- 

 ence consists in the fact that the Fruticosi have aerial, the 

 Herhacei subterraneous stems. The scales which formed this 

 bud are persistent, in a faded condition, at the base of the 

 shoot : they vary in colour, and in their clothing, and may 

 furnish characters of some value when carefully noticed. In 

 the Idcei and Suberecti the shoots spread in two directions 

 (are distichous), but in the other Fruticosi they all turn ti> 

 wards the upper side of the stem. Their leaves are very 

 similar to those of the stem, but much more frequently ter- 

 nate; the lower are sometimes quinate; and the upper floral 

 leaves are frequently simple. 



The panicles are of various forms; their branches are 



2—3 



