. A textbook of botany for colleges and universities ... Botany. LEAVES 585 bananas (fig. 846); (2) evergreens with broad and stiff leaves, the so- called broad-leaved scleraphylls, as the live oak and the holly (fig. 809); (3) evergreens with stiff, needle-like leaves, as in the pine and the spruce (fig- 955); (4) succulent desert evergreens, as Agave (fig. 921); and (5) leafless evergreens, such as the cacti (fig. 1035) and Ephedra. A transition to de- ciduous trees is seen in the potential ever- greens, such as Ilex decidua, which, though deciduous in the northern states (as suggested by th
. A textbook of botany for colleges and universities ... Botany. LEAVES 585 bananas (fig. 846); (2) evergreens with broad and stiff leaves, the so- called broad-leaved scleraphylls, as the live oak and the holly (fig. 809); (3) evergreens with stiff, needle-like leaves, as in the pine and the spruce (fig- 955); (4) succulent desert evergreens, as Agave (fig. 921); and (5) leafless evergreens, such as the cacti (fig. 1035) and Ephedra. A transition to de- ciduous trees is seen in the potential ever- greens, such as Ilex decidua, which, though deciduous in the northern states (as suggested by the specific name), is evergreen farther south, as are various oaks that are decid- uous in the north. Magnolia grandi- flora, a true ever- green in the Gulf states, retains its leaves at its northern limit, although they die before the winter is over, thus resem- bling the beech and those oaks in which the autumnal absciss layer is imperfectly developed. The causes of leaf fall. —The leaf behavior of deciduous trees and of tropical evergreens obviously is related to external factors, in the former being associated with cKmatic periodicity (either of moisture, as in the monsoon forests of India, or of temperature, as in the northern deciduous forests), while in the latter it is associated with uniform moisture and temperature. That the deciduous and the evergreen. Fig. 846. — A group of banana trees (Musa); the gigantic leaves have been much frayed by the wind (marginal me- chanical tissue being poorly developed), giving the effect of a pinnate palm leaf; the shrubs beneath the banana trees are coffee plants (Coffea arabica); Xalapa, Mexico. — Photograph supplied by 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
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Keywords: ., bookcentury1900, bookdecade1910, booksubjectbotany, bookyear1910
