The genera of South African plants : arranged according to the natural system / by William Henry Harvey.

  • William H. Harvey
Date:
1868
Catalogue details

Licence: Public Domain Mark

Credit: The genera of South African plants : arranged according to the natural system / by William Henry Harvey. Source: Wellcome Collection.

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    The epidermis, or surfaee, is said to he, strigose, when short, stiff hairs lie close-pressed to the surface, and all in one direction ; strigillose, when such hairs tire very shoi-t or small. tomentose or cottony, when the hairs are soft, short, dense, somewhat interwoven, and usually white or whitish. xvoolly, when the hairs are loosely intricate and long, like wool. mealy or farinose, when the hairs are very minute, intricate, and white, and come off readily, having the appeartmee of meal or dust. canescent, canons, or hoary, when the hairs are minute, close-pressed, and white, and not readily to he distinguished separately hy the eye, but giving a general whitish hue to the epideimis. glaucous or glaucescent, when of more or less a pale bluish-green, often covered with a bloom like that on a plum or cabbage-leaf. 148. Hairs are often branched. If forked from the base, the forks spreading in opposite directions, the hairs are said to bo attached by the centre, if several branches radiate horizontally, the hairs are stellate, or stiir-liko. Stellate hairs become stellate scales when the rays are confluent at base ; and the surface is said to be scaly or lepidote. 111). Tho tenn gland is given to several different productions, and principally to tho four following:— 1. Small, wart-like or shield-shaped bodies, either sessile or some- times stalked, of cellular or somewhat fleshy consistence, occa- sionally secreting a small quantity of oily or resinous matter, but more frequently dry. They are generally few in number, often definite in their position and form, and occur chiefly on the ])ctiole or piincipal veins of loaves, on tho branches of in- florescences, or on tho stalks or principal veins of bracts, sepals, and petals. 2. Minute raised dots, usually black, rod, or dai’k-coloured, of a resinous or oily natui’o, always supoi-ficial and apparently exudations from the cjudormis. They are often very numerous on leaves, bracts, sepals, and green branches, and occur oven on petals and stamens, more rai-oly on pistils. When raised on slender stalks they ore called pedicellate glands, or glandular hairs, according to the thickness of tho stalk. 3. Small, globular, oblong, or linear vesicles filled with oil, im- bedded in tho substance of leaves, bracts, floral organs, or fruits. They are often very numerous, like transparent dots; somotimes few and dctciminato in form and position. In tho pericaiqi of Umbellifer(C they are remarkably regular’ and con- spicuous, and tako the name of vittce. 4. Lobes of tho disk, or other small, fleshy excrescences within tho flower, whether from the receptacle, calyx, corolla, stamens, or pistils. II. Anatomy and Physiology. {Abridged from the writings of Professor Lindley and Professor Asa Gray.) 150. Vegetable Anatomy, or the study of the microscopical structure of the compound organs of plants, and Vegetable Physiology, or the study of the functions which each organ performs diu-ing life, arc distinct and extensive branches of botany, with which tho merely systematic botanist,
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