. A textbook of botany for colleges and universities ... Botany. 642 ECOLOGY branous sheaths surrounding the stem in the Polygonaceae (fig. 822), while they are coherent with the petiole in the roses (fig. 1094). Stipules may persist through the life of the leaf or they may be caducous ( falling as the buds open, fig- 948); usually in both cases they are precocious in their development, thus affording some protection to the rest of the develop- ing leaf or shoot from transpiration and other detri- mental factors. Probably this is the only role of most caducous stipules, and it is well illu
. A textbook of botany for colleges and universities ... Botany. 642 ECOLOGY branous sheaths surrounding the stem in the Polygonaceae (fig. 822), while they are coherent with the petiole in the roses (fig. 1094). Stipules may persist through the life of the leaf or they may be caducous ( falling as the buds open, fig- 948); usually in both cases they are precocious in their development, thus affording some protection to the rest of the develop- ing leaf or shoot from transpiration and other detri- mental factors. Probably this is the only role of most caducous stipules, and it is well illustrated by the large stipule of Ficus, which encloses the developing blade, faUing as the latter expands (fig. 714). Many cadu- cous stipules are small and have no apparent r61e. Precocious persistent stip- ules also may afford pro- tection, as in the peas (figs. 939, 943), where they stand close together verti- cally, with an undeveloped leaf or shoot enclosed be- tween them; in Lathyrus ochroleucus, frosts may kill young parts protruding from the stipules, while not injuring the enclosed parts. The chief role of persistent stipules, which, in contrast with caducous stipules, are almost always green, is the manufacture of foods; in plants with large stipules, as in the peas, this role assumes quantitative im- portance, and in Lathyrus Aphaca, the stipules much surpass the blades in size and in synthetic capacity. If the developing blades of Prunus serotina are cut away, the stipules grow to a considerable size and live for a longer time than usual; doubtless they manufacture more food than under ordinary 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; Barnes, Charles Reid, 1858-1910, joint author; Cowles, Henry Chandler, 1869- joint author. New York, Cincinnati [
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Keywords: ., bookcentury1900, bookdecade1910, booksubjectbotany, bookyear1910
