. A textbook of botany for colleges and universities ... Botany. 546 ECOLOGY strikingly with the sparse undergrowth of dense shady woods of beech or hemlock, the plants in the latter consisting largely of thin-leaved mosses, ferns, and other shade plants (fig. 784). In early spring our deciduous forests are well lighted, and the undergrowth then displays remarkable activity; while in many plants the leaves remain alive through the sunrmier, in others they soon die (as in Claytonia, Dicentra, and Allium tricoccum). The great intensity of tropical light often permits. Fig. 784. — A plant of wild
. A textbook of botany for colleges and universities ... Botany. 546 ECOLOGY strikingly with the sparse undergrowth of dense shady woods of beech or hemlock, the plants in the latter consisting largely of thin-leaved mosses, ferns, and other shade plants (fig. 784). In early spring our deciduous forests are well lighted, and the undergrowth then displays remarkable activity; while in many plants the leaves remain alive through the sunrmier, in others they soon die (as in Claytonia, Dicentra, and Allium tricoccum). The great intensity of tropical light often permits. Fig. 784. — A plant of wild spikenard {Aralia racemosa), displaying a kind of leafage common in rich mesophytic woods; note the large, compovind diaphototropic leaves with broad leaflets, which are very thin and capable of enduring considerable shade; Manitou Island, Michigan. — Photograph supplied by Thompson. a dense undergrowth in the forest shade; where evergreens prevail, the herbage always is exempt from direct insolation. Vertical leaves. — Some leaves (especially among xerophytes) are slightly if at all diaphototropic, assuming a vertical position through their growth activity. Lactuca scariola, for example, has diaphototropic leaves in the shade, but in the sunlight the leaves twist about into the profile position (fig. 785). In the compass jAajit (Silphium laciniatum) and often in Lactuca the leaves not only are vertical, but also face east or west. In Eucalyptus globulus intense light induces not only a vertical instead of a horizontal position, but a change in leaf form as well. Such changes in reaction accompanying an increase of light in-. 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 Yor
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Keywords: ., bookcentury1900, bookdecade1910, booksubjectbotany, bookyear1910
