INTEODtrCTION. 25 



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



downy, or pubescent, when the hairs are short and soft. 



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

 the surface, all in the same direction. 



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

 more or less intricate, usually white. 



woolly, when the hairs are loosely intricate and long, compared to wool. 



mealy, or farinose, when the hairs are excessively short, intricate, and 

 white, and come off readily, having the appearance of meal. 



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

 tinguished separately by the naked eye, and yet give a' general wliitish hue 

 to the epidermis. 



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

 Hairs are often branched. If forked from the base, and the forks spread 

 along the surface in opposite directions, the hairs are said to be attached by 

 the centre. If several branches radiate horizontally from the base, the hairs 

 are said to be stellate. These stellate hairs are sometimes connected to- 

 gether into httle flat circular disks attached by the centre. These are called 

 scales, and the surface said to be scaly or lepidote, in a very different sense 

 to tliat of the scales (or squamce) defined above (p. 9) as reduced leaves. 



The sense here attached to the terms expressive of the different kinds of 

 hairiness is in each case that which appears to be the most generally 

 adopted, but it is often very vague. Different botanists will often use very 

 different terms to express the same kind of hah-iness. This is especially the 

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

 ness is however so very variable a character inmost plants, that some vague- 

 ness cannot be avoided, and is of comparatively little consequence. 



The name of Glands is given to several different productions, and princi- 

 pally to the four following : — 



1. Small wart-hke or shield-shaped bodies, either sessile or sometimes 

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

 a small quantity of oUy or resinous matter, but more frequently dry. They 

 are generally few in number, often definite in then* position and form, and 

 occur chiefly on the petiole or principal vems of leaves, on the branches of 

 inflorescences, or on the stalks or principal veins of bracts, sepals, and 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 very 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 glands or glan- 

 dular 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 pericai-p of UmbeUiferse they are remarkably 

 regular and conspicuous, and take the name of vittce. 



4. Lobes of the disk or other small fleshy excrescences within the flower, 

 whether from the receptacle, calyx, corolla, stamens, or pistils. 



