. A text-book of botany for secondary schools. Botany. STEMS 65 of the water-lilies, from which arise the leaves with large floating blades (pads). Therefore, a rhizome does not nec- essarily bear only scale leaves, but may develop also leaves that become aerial; and in that case they are usually large. It is evident that in plants possessing rhizomes the subterranean stems are perennial, while the aerial parts may be annual. (5) Tubers.—In some plants the ends of underground stems become very much enlarged for food storage. These enlargements are called tubers, the best-known illustration bei
. A text-book of botany for secondary schools. Botany. STEMS 65 of the water-lilies, from which arise the leaves with large floating blades (pads). Therefore, a rhizome does not nec- essarily bear only scale leaves, but may develop also leaves that become aerial; and in that case they are usually large. It is evident that in plants possessing rhizomes the subterranean stems are perennial, while the aerial parts may be annual. (5) Tubers.—In some plants the ends of underground stems become very much enlarged for food storage. These enlargements are called tubers, the best-known illustration being the common potato (Fig. 64). That it is a stem structure is evident from the fact that it bears very much. FlG. 64.—Potato tuber showing eyes (scale leaves and axillary buds). reduced leaves, in the axils of which are buds, the so-called "; Abnormally developed potatoes often show the shoot character of the tuber very plainly, and in the case of potatoes sprouting it is evident that the eyes have de- veloped into branches. In planting potatoes, advantage is taken of the fact that any node placed in proper conditions may strike root and put out a branch. Since the eyes are branch buds standing at nodes, and any piece of the potato containing a bud is able to produce a new plant, it is customary to cut the potato into pieces, being careful that each piece contains one or more eyes. Heaping up the soil (hilling up) about the base of the potato plant induces the formation of more of the subterranean, tuber-bearing. 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 Merle, 1851-1928. New York, D. Appleton
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