LEAFLETS. 



91 



of the leaf. They are, however, equally applicable to the sur- 

 face of any other organs. (41, a.) 



1. Glabrous, smooth; denoting the absence of all hairs or bristles. Hydrangea. 



2. Pubescent, covered with soft hairs or down. LoniceraXylosteum. 



3. Rough, with hard, short, even points. Borago officinalis. 



4. Pilose, with short, weak, thin hairs. Prunella vulgaris. 



5. Hoary, white, with very short, dense hairs. Gnaphalium. 



6. Villose, with long, thin hairs. Solidago altissima. 



7. Woolly, with long, dense, matted hairs. Mullein. 



8. Tomentose, with dense, short, and rather rigid hairs. Spirea tomentosa. 



9. Rugose, the tissue between the reticulated veins convex, from its superabun- 

 dance. Sage. 



10. Punctate, dotted with pellucid glands (44, a). Hypericum punctatum. 



3. COMPOUND LEAVES. 



FIG. 32. Compound leaves. 4, Trifoliate leaves ; a, pinnately, as of the bean ; b, pal- 

 mately, clover 



238. When a simple leaf becomes a compound one, the divis- 

 ion takes place upon the same principle as the separation of an 

 entire leaf into segments, lobes, and teeth, namely, from a defi- 

 ciency of parenchyma; the number and arrangement of the 

 leaflets will therefore, in like manner, depend upon the mode of 

 veining. 



239. The divisions of a compound leaf are called LEAFLETS, 

 and the same distinctions of outline, margin, &c., occur in them 

 as in simple leaves. In the truly compound leaf, each leaflet 



