FORMS OF COMPOUND LEAVES. 



91 



often terete. They are either barren or bear flowers. Their cellular 

 tissue is often stellate, 

 and the shoots some- 

 times exhibit a pe- 

 culiar spiral twisting. 

 (Fig. 190.) 



Compound Leaves 

 are those in which the 

 divisions extend to the 

 midrib, or petiole (fig. 

 191), and receive the 

 name oifoliola or leaf- 

 lets. The midrib, or 

 petiole, has thus the 

 appearance of a branch 

 with separate leaves 

 attached to it, but it is 

 considered properly as 

 one leaf, because in its 

 earliest state it arises 



"■"I'""*'' "i»»""iiiiiiiiiiiiiiiiiiiii)iiiaw.iS5i 



Kg. 190. 



Kg. 191. Kg. 192. 



Fig. 190. Junous effusus, variety, with spiral leaves, called Sorew-rusli. . Fig. 191. Leaf 

 of Robinia pseudacacia, often called Acacia. The leaf is impari-pinnate, or alternately pin- 

 nate, The pinnse are supported on atallss or petiolules. p, Petiole or leaf -stalk. I, Lamina 

 ■ or blade divided into separate leaflets or pinna. Fig. 192. Septenate leaf of Horse Chest- 

 nut (^sealms Hippoeastwmm). p, Petiole. I, Lamina divided into seven separate 



