FOLIAGE LEAVES. 



405 



775. Rosette pattern. The rosette pattern is presented by 

 many plants with "radial" leaves, or leaves which arise in a 

 cluster near the surface 



of the ground, and are 

 thus more or less crowded 

 in their arrangement on 

 the stem. The pretty 

 gloxinia often presents 

 fine examples of a loose 

 rosette. In the rosette 

 pattern the petioles of 

 the lower leaves are 

 longer than the upper 

 ones, and the blade is 

 thus carried out beyond 

 the inner ] eaves. The 

 leaves being so crowded 

 in their attachment to 

 the stem lie very nearly 

 in the same plane. 



776. Vines and climbers. Some of the most extensive mosaic 

 patterns are shown in creeping and climbing vines. A very 

 common example is that of the ivies trained on the walls of build- 

 ings, covering in some instances many square yards of surface. 

 Where the vines trail over the ground or clamber over other 

 vegetation, it is interesting to observe the various patterns, and 

 the distortion of petioles brought about by turning of the leaves. 

 Of examples found in greenhouses, the Pellonia is excellent, and 

 the trailing ribbon-grass often forms loose mosaics. 



777. Branch patterns. These patterns are very common. 

 They are often formed in the woods on the ends of branches by 

 the leaves adjusting themselves so as to largely avoid shading 

 each other. Figure 443 illustrates one of them from a maple 

 branch. It is interesting to note the way in which the leaves 

 fit themselves in the pattern, how in some the petioles have 

 elongated ; while others have remained short. Of course, it 



Fig. 442. 

 Rosette pattern of leaves. 



