Ch. Ill, 8) FORMS OF FOLIAGE LEAVES 



65 



and that with linear leaves, and the ovate shape approxi- 

 mates to orbicular at base and linear at tip. It is therefore 

 quite consistent that when the leaves become more crowded 

 on the branches, as 

 in Chestnut and 

 Beech, the ovate 

 shape tends towards 

 linear, resulting in a 

 spindle form ; but 

 when on the con- 

 trary the leaves are 

 more fully spread 

 out, the ovate tends 

 towards orbicular, 

 with the great veins 

 coming to radiate 

 from an elongated 

 petiole, as in Red- 

 bud. The tendency 

 towards orbicular 

 goes farther in heart- 

 shaped leaves, like 

 Linden and Violet, 

 and ultimately leads 

 back to the true or- 

 bicular with central- 

 standing petiole. 

 Between orbicular, 



sta 

 lin 



Fio. 35. — Cordyline australis, the "Dra- 

 cona Palm," showing radiate heads of linear 

 leaves. (From Bailey, Cyclopedia.) 



ear, and ovate forms, there occur all gradations, giving a 

 great diversity of forms. Many of these have been named 

 from their resemblance to common objects (e.g. lanceolate, 

 spatulate, reniform, peltate) ; and such designations find con- 

 stant use in the descriptions of plants contained in floras and 

 manuals. 



Closely connected with the shapes of leaves is their 

 venation. Orbicular and ovate leaves are typically netted- 



