. Plant life and plant uses; an elementary textbook, a foundation for the study of agriculture, domestic science or college botany. Botany. PROTECTION 247 The yellowness of leaves is not due to a newly manu- factured substance. It is due to a substance called xan- thophyll which is present in chlorophyll all the time. The yellowness of xanthophyll does not show in active leaves. It is obscured by the green. But as the chloroplast begins to break down in the dying leaf, its greenness disappears, and the color of the xanthophyll begins to show. B. Movements of Leaves. — The most striking case of
. Plant life and plant uses; an elementary textbook, a foundation for the study of agriculture, domestic science or college botany. Botany. PROTECTION 247 The yellowness of leaves is not due to a newly manu- factured substance. It is due to a substance called xan- thophyll which is present in chlorophyll all the time. The yellowness of xanthophyll does not show in active leaves. It is obscured by the green. But as the chloroplast begins to break down in the dying leaf, its greenness disappears, and the color of the xanthophyll begins to show. B. Movements of Leaves. — The most striking case of the movement of leaves is the case of the sensitive plant. Perhaps you have seen this plant. It is a native of the tropics, but it is common in greenhouses. It is a small creeping plant having somewhat the habit of growth of the strawberry. Its com- pound leaves are com- posed of many small opposite leaflets. If the plant is touched or affected by vibra- tion, first these leaflets fold together, and then the whole leaf bends down as on a hinge -pw at the base of the petiole. (See Figure 86.) These same movements are produced, but more gradually, by — Movement of the leaves of the sensitive plant {Mimosa pudica); m, pulvinus, s, stipule. See 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 Coulter, John G. (John Gaylord), b. 1876. New York, American Book Co
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Keywords: ., bookcentury1900, bookdecade1910, booksubjectbotany, bookyear1913
