. Plant life and plant uses; an elementary textbook, a foundation for the study of agriculture, domestic science or college botany. Botany. 208 LEAVES which are called leaflets. Leaves may be very deeply divided, but still they are classed as simple unless the blade is completely divided into leaflets. Compound leaves are nearly always net-veined. A branching pinnate leaf is said to be pinnately compound; a branching palmate leaf is said to be palmately compound. Leaves of locust or ash (see page 187) are examples of the former; leaves of clover are examples of the latter. (See Fig- ure 71.) C
. Plant life and plant uses; an elementary textbook, a foundation for the study of agriculture, domestic science or college botany. Botany. 208 LEAVES which are called leaflets. Leaves may be very deeply divided, but still they are classed as simple unless the blade is completely divided into leaflets. Compound leaves are nearly always net-veined. A branching pinnate leaf is said to be pinnately compound; a branching palmate leaf is said to be palmately compound. Leaves of locust or ash (see page 187) are examples of the former; leaves of clover are examples of the latter. (See Fig- ure 71.) C. Attachment and Arrangement. — Leaves are commonly attached to stems by petioles. The end of the petiole which is attached to the stem is usually somewhat enlarged. When this enlargement appears to form a special organ it is called the pulvinus. Leaf movements are generally due to change in the water content of the cells of the pulvinus; such movements are characteristic of the clovers and locusts. In some groups of plants, especially in the great rose and pea families, a pair of structures like small leaf blades are borne at the base of the petiole; these are called stipules. (See Fig- ures 70 and 77.) Many leaves do not have petioles; their blades begin. B Fig. 71. — Compound leaves: A, pinnately compound leaf ol black locust; B, palmately compound leaves of red clover. The clover leaves have sheathing stipules at the base of the 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
