XXXVI INTRODUCTION . 



echinate, when the protuberances are longer and sharper, almost prickly. 



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



glandular -setose, when the setae or bristles terminate in a minute resinous 

 head or drop. In some works, especially in the case of Roses and Rubus, the 

 meaning of setce has been restricted to such as are glandular. 



glochidiate, when the setae are hooked at the top. 



pilose, when the surface is thinly sprinkled with rather long simple hairs. 



hispid, when more thickly covered with rather stiff hairs. 



hirsute, when the hairs are dense and not so stiff. 



doivny or pubescent, when the hairs are short and soft ; puberulent, when 

 slightly pubescent. 



strigose, when the hairs are rather short and stiff, and lie close along the 

 surface all in the same direction ; strigillose, when slightly strigose. 



tomentose or cottony, when the hairs are very short and soft, rather dense 

 and more or less intricate, and usually white or whitish. 



woolly (lanate), when the hairs are long and loosely intricate, like wool. 

 The wool or tomentum is said to befloccose when closely intricate and readily 

 detached, like fleece. 



mealy (farinose), when the hairs are excessively short, intricate and white, 

 and come off readily, having the appearance of meal or dust. 



canescent or hoary, when the hairs are so short as not readily to be distin- 

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



glaucous, when of a pale bluish-green, often covered with a fine bloom. 



174. The meanings here attached to the above terms are such as appear to 

 have been most generally adopted, but there is much vagueness in the use 

 practically made of many of them by different botanists. This is especially the 

 case with the terms pilose, hispid, hirsute, pubescent, and tomentose. 



175. The name of Glands is given to several different productions, and 

 principally to the four following : — 



1. Small wart-like or shield-like bodies, either sessile or sometimes stalked, 

 of a fungous or somewhat fleshy consistence, occasionally secreting a small 

 quantity of oily or resinous matter, but more frequently dry. They are gene- 

 rally few in number, often definite in their position and form, and occur chiefly 

 on the petiole or principal veins of leaves, on the branches of inflorescences, or 

 on the stalks or principal veins of bracts, sepals, or petals. 



2. Minute raised dots, usually black, red, or dark-coloured, of a resinous 

 or oily nature, always superficial, and apparently exudations from the epidermis. 

 They are often numerous on leaves, bracts, sepals, and green branches, and 

 occur even on petals and stamens, more rarely on pistils. When raised upon 

 slender stalks they are called pedicellate (or stipitate) glands or glandular 

 hairs, according to the thickness of the stalk. 



3. Small, globular, oblong or even linear vesicles, filled with oil, imbedded 

 in the substance itself of leaves, bracts, floral organs, or fruits. They are often 

 very numerous, like transparent dots, sometimes few and determinate in form 

 and position. In the pericarp of Umbelliferce they are remarkably regular and 

 conspicuous, and take the name of vittce. 



4. Lobes of the disk (137), or other small fleshy excrescences within the 

 flower, whether from the receptacle, calyx, corolla, stamens, or pistil. 



Chap. II. — Classification, or Systematic Botany. 



176. It has already been observed (3) that descriptions of plants should, as 

 nearly as possible, be arranged under natural divisions, so as to facilitate the 



