ELLMENTARY BOTANY. Xxiil 



171. Hairs, in the general sense, or the indumentum (or clothing) of a plant, in- 

 clude all those productions of the epidermis which have, by a more cr less appropriate 

 comparison, been termed bristles, hairs, down, cotton, or wool. 



172. Hairs are often branched. They are said to be attached by the centre, if 

 parted from the base, and the forks spread along the surface in opposite directions ; 

 plumose, if the branches are arranged along a common axis, as in a feather ; stellate, 

 if several branches radiate horizontally. These stellate hairs have sometimes their 

 rays connected together at the base, forming little flat circular disks attached by the 

 centre, and are then called scales, and the surface is said to be scaly or lepidote. 



173. The Epidermis, or outer skin, of an organ, as to its surface and indumentum, 

 is 



smooth, when without any protuberance -whatever. 

 glabrous, when without hairs of any kind. 

 glabrescent, glabrate, becoming glabrous. 



striate, when marked with parallel longitudinal lines, either slightly raised or 

 merely discoloured. 



furrowed (sulcate) or ribbed (costate) when the parallel lines are more distinctly 



rugose, when wrinkled or marked with irregular raised or depressed lines. 



umbilicate, when marked with a small round depression. 



umbonate, when bearing a small boss like that of a shield. 



viscous, viscid, or glutinous, when covered with a sticky or clammy exudation. 



scabrous, when rough to the touch. 



tuberculate or warted, when covered with small, obtuse, wart-like protuberances. 



muricate, when the protuberances are more raised and pointed but yet short and 



echmate, -when the protuberances are longer and sharper, almost prickly. 

 setose or bristly, when bearing very stiff erect straight hairs. 

 glandular-setose, when the seta? or bristles terminate in a minute resinous head 

 r r °P- *n some works, especially in the case of Eoses and Bubus, the meaning of 

 * ha8 been restricted to such as are glandular. 

 glochidiate, when the seta; are hooked at the top. 



Pi'ose, -when the surface is thinly sprinkled with rather long simple hairs. 

 tospid, when more thicklv covered with rather stiff hairs. 

 hirsute, when the hairs nVe dense and not so stiff, 

 pubes"'*' ° r pwbescent > wlien lhe hairs are short and soft; pubemlent, when slightly 



all in'f? **' When the hairs are rather short and 8tiff ' and lie close al ° ng thC 8urface 



'the same direction ; slrigillose, when slightly strigose. 

 mor e . ntose or cottony, when the hairs are very short and soft, rather dense and 



6 ° r Jf 8 intricate, and usually white or whitish, 

 wool f ( l <*nate), when the hairs are long and loosely intricate, like wool. The 

 like fl° r mentum is said to be floccose when closely intricate and readily detached, 



come^ff (S arinose )> when the hairs are excessively short, intricate and white, and 



- readily, having the appearance of meal or dust, 

 by the t CW ' ° r hoar y> wh en the hairs are so short as not readily to be distinguished 

 naked eye, and yet give a general whitish hue to the epidermis. 



s ' auco ^, when of a pale bluish-green, often covered with a fine bloom. 



174 Trvf ?CeW '' su bgl a ucous or becoming glaucous. 



been m 7* mean ings here attached to the above terms are such as appear to have 

 ttiade nf generally adopted, but there is much vagueness in the use practically 

 t ermspi/ nany . of . ,hem b ? differe nt botenists. This is especially the case with the 



175 TV.**' ^' s l"'d> hirsute, pubescent, and tomentose. . 



to the fo V ame of Gl «"»ds ia given to several different productions, and principally 



iour following : — 

 faneo.",* H w,lrt -like or shield-like bodies, either sessile or sometimes stalked of a 

 b " or «>mewhat fleshy consistence, occasionally secreting a small quantity of ouy 



