Platanaceae
A very small natural order of usually tall trees, with flaking bark; they inhabit the temperate or sub-tropical regions of the Northern hemisphere, two are natives of East Europe or Asia, and the rest are American. Flowers monoecious, in unisexual, globose, densely-crowded heads; "the stamens in the males, and the ovaries in the females, are mixed, without definite order, with scales, which may be bracts, perianth segments, or staminodes, or arrested ovaries" (J. D. Hooker). Fruit a nut. Leaves alternate, petiolate, broad, palmately nerved and lobed; petioles dilated at base; stipules membranous, caducous. The only genus of the order--Platanus--comprises only five or six species, which are mainly valuable for their timber and ornamental appearance.