. Plants and their ways in South Africa. Botany; Botany. Plant Defences 105 also hindered. Place a silver leaf in water and notice how the silvery sheen is brightened. The thick coat of hairs retains a layer of air which the rain cannot replace. It is because of this that vapour can pass off without interruption. A bamboo leaf under water glistens on the lower surface cjuite as brilliantly, but the upper surface comes out wet. The stomata which are most numerous on the under surface are sunken, ajid protected by projecting rods of wax. On the upper surface wax is want- ing but the few stomata
. Plants and their ways in South Africa. Botany; Botany. Plant Defences 105 also hindered. Place a silver leaf in water and notice how the silvery sheen is brightened. The thick coat of hairs retains a layer of air which the rain cannot replace. It is because of this that vapour can pass off without interruption. A bamboo leaf under water glistens on the lower surface cjuite as brilliantly, but the upper surface comes out wet. The stomata which are most numerous on the under surface are sunken, ajid protected by projecting rods of wax. On the upper surface wax is want- ing but the few stomata are protected in another Fig. 88.—Vegetation in the Karroo where there are long droughts. The soil is alkaline. Peculiar colourless cells of the epidermis lie in rows midway between the veins. When there is sufficient moisture these pro- ject above the surface. As moisture is withdrawn, they col- lapse without injury, allowing the leaves to roll : the stomata lying on either side of these cells are thus covered. A bamboo leaf which has withered for several days will re- vive if a stream of water is allowed to flow over the upper sur- face. While the wax rods make it impossible to wet the under surface, thin walled cells on the upper surface actually absorb moisture. The sugar bush has another cunningly devised method of. 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 Stoneman, Bertha. London, New York, Longmans, Green
Size: 1990px × 1255px
Photo credit: © The Book Worm / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookcentury1900, bookdecade1910, booksubjectbotany, bookyear1915
