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''Notholithocarpus densiflorus'', commonly known as the tanoak or tanbark-oak, is an evergreen tree in the beech family (Fagaceae), native to the western United States, in California as far south as the Transverse Ranges, north to southwest Oregon, and east in the Sierra Nevada. It can reach tall (though is more usual) in the California Coast Ranges, and can have a trunk diameter of . Tanbark-oak was recently moved into a new genus, ''Notholithocarpus'' (from ''Lithocarpus''), based on multiple lines of evidence. It is most closely related to the north temperate oaks, ''Quercus'', and not as closely related to the Asian tropical stone oaks, ''Lithocarpus'' (where it was previously placed), but instead is an example of convergent morphological evolution. ==Description== The ''Notholithocarpus (prev. Lithocarpus) densiflorus'' leaves are alternate, , with toothed margins and a hard, leathery texture, and persist for three to four years. At first they are covered in dense orange-brown scurfy hairs on both sides, but those on the upper surface soon wear off, those on the under surface persisting longer but eventually wearing off too. The seed is a nut long and 2 cm in diameter, very similar to an oak acorn, but with a very hard, woody nut shell more like a hazel nut. The nut sits in a cup during its 18-month maturation; the outside surface of the cup is rough with short spines. The nuts are produced in clusters of a few together on a single stem. The nut kernel is very bitter, and is inedible for people without extensive leaching, although squirrels eat them. Tanoak is one of the species most seriously affected by "sudden oak death" (''Phytophthora ramorum''), with high mortality reported over much of the species' range. 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Notholithocarpus」の詳細全文を読む スポンサード リンク
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