. The botany of crop plants : a text and reference book. Botany, Economic. STEMS --barK . .wood .pith food of the plant is manufactured in the chlorophyll-bear- ing (green) cells above ground. 2. Tubers.—These are fleshy, underground stems. The best example is common Irish potato. Although the potato, ordinarily, would not be considered a stem, still if we follow through its development, and examine its structure, we are convinced that it is stem (Fig. 12). When we plant a sUce of a potato, "sprouts" are soon sent out from the "; These sprouts, with their nodes, and in
. The botany of crop plants : a text and reference book. Botany, Economic. STEMS --barK . .wood .pith food of the plant is manufactured in the chlorophyll-bear- ing (green) cells above ground. 2. Tubers.—These are fleshy, underground stems. The best example is common Irish potato. Although the potato, ordinarily, would not be considered a stem, still if we follow through its development, and examine its structure, we are convinced that it is stem (Fig. 12). When we plant a sUce of a potato, "sprouts" are soon sent out from the "; These sprouts, with their nodes, and internodes, and their scale leaves, are quite obviously horizontal under- ground stems (rhizomes). Soon, the tip of a rhizome begins to en- large, and a potato is formed; hence, the potato is seen to be a simple enlargement of the tip of an underground stem. Furthermore, examination of the tuber reveals the presence of a terminal bud ("seed end" of the potato), and lateral buds along the sides. The buds are the so-called "; In an elongated potato, we may be able to detect the spiral ar- rangement of the buds. Lenticels may also be observed on the corky layer (skin) of the bark of the potato. A section of a tuber reveals a stem structure. The three principal parts of an ordinary stem are bark, wood and pith. This is shown in a cross-section of an ordinary twig (Fig. 13). In the potato, these three distinct zones are visible, as indi- cated in Fig. 236. Hence, we see that the potato is in reality a modified Fig. 13.—Section of stem showing a shedding leaf; also bark, wood and pith as seen in cross and longitudinal sec- tions. {After Longyear.). 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 Robbins, Wilfred William, 1884-1952. Philadelphia : P. Blakiston's Son
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Keywords: ., booka, bookcentury1900, bookdecade1910, booksubjectbotanyeconomic
