. Botany of the living plant. Botany; Plants. BOTANY OF THE LIVING PLANT the former especially on the dry areas of the (>ld, the latter of the New Worl • Insomi is the stem swells to an almost spherical term, by which humus the greatest possible proportion of bulk to : By virtue of the water stored up within its tissues a , can live for several months without any external supply of water. A spiny or thorny character is common in Xerophytes (Fig. 1411. and is a marked feature in dry districts such as the veldt of ith Africa. A consequence of this is protection against the attac
. Botany of the living plant. Botany; Plants. BOTANY OF THE LIVING PLANT the former especially on the dry areas of the (>ld, the latter of the New Worl • Insomi is the stem swells to an almost spherical term, by which humus the greatest possible proportion of bulk to : By virtue of the water stored up within its tissues a , can live for several months without any external supply of water. A spiny or thorny character is common in Xerophytes (Fig. 1411. and is a marked feature in dry districts such as the veldt of ith Africa. A consequence of this is protection against the attack of herbivorous animals. Many Xerophytes possess extensive and deep root-systems ( Wehuitschia) ; moreover, their root-hairs are characterised by high osmotic pressures and this allows them to dehydrate the soil more thoroughly than is usual in Mesophytes. Along with these features go various other structural modifications. Thickened epidermal walls and cuticle are common (Fig. 142), and this. Fig. 142. Part of a transverse section of the xerophytic leaf of Hakea, showing a stoma lv depressed below the well-developed epidermis, which has greatly thickened , covered by a thick, continuous cuticle. ( > 150.) F. O. B. together with a free development of mechanical tissue frequently gives the es a leathery texture. Hairiness is common. The stomata are frequently sunk in deep pits (Figs. 52, 142) in which a pocket of moist air collects and is likely to impede diffusion through the pore. Hairs have a like effect on eva- poration from the cuticle. Protection of stomata is also achieved in other • s by the lengthwise rolling of the leaf in such a way that the stomata lie. Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - coloration and appearance of these illustrations may not perfectly resemble the original Bower, F. O. (Frederick Orpen), 1855-1948; Wardlaw, C. W. (Claude Wilson), 1901-. Lond
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Keywords: ., bookcentury1900, bookpublis, booksubjectbotany, booksubjectplants
