'452 



DIFFERENT KINDS OF ROUGHNESS. 

 CHAP. XVIII. 



OF PUBESCENCE. 



PUBESCENCE, downiness*, is an armature, by which plants 

 are defended from external injuries. Pubescence is of the fol» 

 lowing kinds, viz. 



Scabrities, roughness; which is composed of particles scarce 

 visible to the naked eyef, that are scattered over the surface of 

 the plant. This is distinguishable into, 



I. Scabrities Glandulosa, a glandulose roughness ; when it con- 

 sists of little glands, which are either, 



1. Miliary, like grains of millet. 



2. Vesicular, composed of bladders. 



3. Lenticular, resembling lentils. 



4. Globular, globe-shaped ; as in ATRiPLEx,...and Chenopo- 

 bium. 



5. Secretory, serving for secretion, 



6. Catenulate, consisting of little chains ; or, 

 . 7. Utricular, like little bottles. 



II. Scabrities Setacea, a bristly roughness ; when it consists of 

 bristles, which are either, 



1. Cylindric, like a cylinder. 



* The term downhiess is not to be taken here in too strict a sense, as the fol- 

 ia wing explanations show. 'Author. 

 •f Guettard was the first who carefully examined this kind of pubescence. 



Editqr. 



