ORGAXS OF NTTEITIOX. 



157 



Vitis-idcBCi) and the leaflets of Logwood; or when under the 

 same circumstances the notch is sharp, or nearly triangular, 

 it is emarginate, as in some kinds of Senna {Cassia obovatd) 

 {fig. 309), and common Box {Bv.xv.s sempemrens). "When the 

 lamina terminates Ter\' abruptly, as if it had been cut across in a 

 straight line, the apex is truncate, as in the leaf of the Tulip- 

 tree {Liriodendron tidipifcra) {fig. 310); or if under the same 



Fig. 309. 



Fig. 310. 



Fig. 309. Leaflet of Cassia obovata. It is obovate in form, oblique at tlie 



base, and emarginate at its apex. Fig. 310. Branch of Tulip-tree 



(Liriodeiidron tidipifera) with flower and leaves. The latter terminate 

 abruptly, hence they are said to be truncate. 



circumstances the termination is ragged and irregular, as if it 

 had been bitten off, it is prceraorse, as in the leaf of Caryota 

 urens. When the apex is sharp, so that the two margins form 

 an acute angle with each other {figs. 312 and 319), it is acute 

 or sharp-pointed, as in the leaf of the Lady's Slipper {Cypripe- 

 dium Calceolus) and most lanceolate leaves; when the point 

 is very long, and tapering {fig. 317), it is acuminate or tafer- 

 pointed, as in the leaf of the White Willow {Salix alba) and 

 common Eeed {Fhragynites cojnrnunis) ; or when it tapers 

 gradually into a rigid point, it is cuspidate, as in many Rubi. 

 When the apex is rounded, and has a short hard or softened 

 .point standing on it, it is mucronate, {fig. 316), as in the leaf of 

 Statice mucronata and Lathy rus pratensis. 



4. Genercd Outline. — By the general outline of the lamina we 

 understand the superficial aspect or figure which is described by 

 its margins. This is subject to great variations, depending, as 

 we have seen, according to DeCaudoUe (p. 151), upon the direc- 

 tion and length of the veins. The development of veins and 

 parench}Tna is usually nearly equal on the two sides of the 

 midrib, or petiole, so that the lamina of the leaf is in most in- 

 stances nearly symmetrical and of some regular figure ; in which 

 case the leaf is said to be eq\ud{fig. 319). When, as occasionally 

 happens, the lamina of the leaf is more developed on one side 



