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Close-up of a specimen of branches from a scrub oak (quercus dumosa), ca.1920

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Mendeley Data2024-01-31 更新2024-06-27 收录
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Photograph of a close-up of a specimen of branches from a scrub oak (quercus dumosa), ca.1920. The edges of the leaves are curly and have prickly points at the end of each curve. The branch holds several acorns (still attached) and a large circular ball (fruit?). "This is a large group of evergreen and deciduous trees and shrubs that are found wild throughout Europe, Asia, northern Africa, and North and South America. Some require tropical or sub-tropical conditions to survive, while the majority are hardy in the North. The Oaks are varied in their appearance; it is hard to believe that some kinds can be classified with the same species. They do, however, have one characteristic in common, which is the fact that their seeds are carried in little caps. Acorns vary considerably with the different kinds of Oak trees. Some have stalked or stalkless caps; in some, the caps only enclose the base of the acorn, while in some, only the tip peaks out. Some caps are rough because they're made of irregular scales; others are smooth because their scales are even and smooth. Some acorns mature six months after the flowers appear and some take as long as 18 months to ripen. Male and female flowers appear on the same tree. The male flowers are borne in noticeable thin, catkins and the inconspicuous female flowers are produced two or more, or sometimes singly on a short stalk. As mentioned above, some Oaks lose their leaves and some don't and some need warmer climates than others. A few will be described for each of these characteristics." -- unknown author.; "North American leaf-losing Oaks are divided into two groups. One is the White Oak group, in which the leaves and lobes of the leaves don't end in bristles, and the acorns ripen during the first year; the other is the Black Oak group, which produces acorns that ripen the second year and the lobes of the leaves are usually tipped with bristles. Q. alba, the White Oak, is a native from Maine to Florida and Texas. This tree is one of the largest of the trees. On average, they will grow from 60 to 80 feet high, but they frequently grow much larger. The leaves are from 5 to 9 inches in length and about half that in width. They have from 5 to 9 (usually 7) rounded lobes. They are smooth, bright green above and whitish beneath. The acorns have short stalks. They are egg-shaped, light brown and shiny, about 3/4-inch in length. Only about a quarter of their length is covered by the cap. In the autumn, the foliage turns a beautiful purplish-red color. Q. coccinea, the Scarlet Oak, is a member of the Black Oak group (the former, Q. alba, was a member of the White Oak group). This is one of the most beautiful of the American Oaks. It grows up to 80 feet high with a diameter of 1 or 2 feet. When young, it has a somewhat pyramidal crown, but as it gets older it develops a broad, round head. The leaves are from 3 to 6 inches long. There are from 5 to 9 long, narrow lobes, which are tipped with bristles and sparingly toothed. The tops of the leaves are dark green and glossy and below they are paler and fairly smooth. The nuts are light reddish-brown with a brown cap, which covers about half of the nut. In the fall, the leaves turn a gorgeous scarlet." -- unknown author.
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2024-01-31
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