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Photo Information
Copyright: Georgia Panakia (g_panakia) Silver Star Critiquer/Silver Note Writer [C: 15 W: 0 N: 32] (199)
Genre: Plants
Medium: Color
Date Taken: 2008-10-26
Categories: Trees
Exposure: f/9.0, 1/50 seconds
Photo Version: Original Version
Date Submitted: 2008-11-01 13:54
Viewed: 3730
Points: 4
[Note Guidelines] Photographer's Note
The genus Platanus is the only one in the dicotyledon family Platanaceae. It arose early in the evolution of flowering plants, and fossil specimens are known from the earlier Cretaceous period, over 100 million years ago.There are about 6-10 species of plane tree, depending on botanic authority. New species have been described recently for North America. All plane trees are from the northern hemisphere, mostly in temperate regions. Two species are from the Old World; Platanus kerrii is the only tropical species, found in Indochina, and it is sometimes placed in a separate subgenus. Platanus orientalis is found from West (and perhaps South) Asia and South Europe. Several others, including Platanus occidentalis, Platanus racemosa, Platanus wrightii, Platanus lindeniana and perhaps others are from North America. Platanus kerrii is evergreen, and the others are deciduous.Their preferred natural habitat is river valleys and wetlands in warmer temperate regions, but they can tolerate dry conditions after establishment. All are large trees, generally 20-50m high. A common characteristic is flaking bark that peels away in sections or sheets, leaving a dappled trunk.
Leaves are borne alternately on the stem. They are always simple (not split into leaflets). In most species they are palmately lobed and veined, (in Platanus kerrii leaves are unlobed, pinnately serrate and pinnately veined). Juvenile leaves are distinct from adult leaves, being more deeply and narrowly lobed in most species. The axillary bud on the shoot is covered completely during the growing season by the base of the petiole, which may be swollen to accommodate it. The shoots and young leaves are covered by hairs or a fine down when young, this is probably to protect the young tissue from sunlight and water loss. The hairs are usually shed as the leaves mature, but sometimes they are partially retained on the underside of the leaves. Stipules are usually present, part of each stipule forming a tube around the shoot, the rest of it forming a leaf-like extension.Plants are bisexual - both sexes borne on the same tree. Male and female flowers are borne on separate spherical inflorescences, which hang on fibrous stalks. They are wind pollinated. The female flower-heads are more showy, generally greenish flushed red or purple, colour varying with the clone, sometimes entirely green or a bright sea-green. The flowers form dense spherical heads, sometimes separately stalked, 1 to 12 on a stem. Of the forms seen in Britain, the oriental plane has the greatest number of female flower heads per stem, up to 6. There may be between 3 and 8 each of petals and sepals. There are between 3 and 4 anthers on the male flowers and between 6 and 9 pistils on the female flowers. The flowers may be covered by hairs as in the leafy shoot. Each female flower becomes an achene, united with the others on the flower-head to form the spherical fruit. Often the styles persist to form bristles or prickles on the seed, and they aid dispersion of the seed. The fruits persist through the winter on the temperate species. They then distintegrate in early spring, generally while still on the tree, releasing the achenes.

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beautiful photo...

  • Great 
  • azaf1 (42)
  • [2009-02-13 11:50]

Kalo ...........

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