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Trees can be identified by examination of several characteristics. The following guide applies to the trees which are indigenous to the region extending from the Atlantic Ocean to the Rocky Mountains and from Canada to the northern boundaries of the southern states, together with a few well-known and naturalized foreign trees. The typical leaves of a species are to be found upon mature trees, not upon young ones. The leaflets of a compound leaf can be distinguished from simple leaves by the absence of leaf buds from the base of their stems. To identify a tree check a characteristic and if it is present then examine the characteristics at the next level of indentation. For example, if the tree has simple leaves then see whether the leaves alternate along stem or leaves are opposite along stem. This guide does not include the Conifers, which are cone-bearing seed plants with vascular tissue. * Simple leaves * * Leaves alternate along stem * * * Margins entire * * * * Oblong-ovate or obovate, large, thick: Magnolia * * * * Oblong, sub-evergreen at the south: Sweetbay Magnolia * * * * Evergreen: Rhododendron, Kalmia * * * * Obovate, 15-30 cm long: Pawpaw * * * * Oblong, thick, shining, 5-12 cm long: Black Tupelo * * * * Oblong, tree occurring sparingly at the north: American persimmon * * * * Heart-shaped: Eastern Redbud * * * * Leaves of three forms; oval, two-lobed, or three-lobed; frequently all three on one spray: Sassafras * * * * Thick, shining, willow-shaped: Shingle oak, Willow Oak * * * * Thick, shining, ovate, spines in the axils: Osage-orange * * * * Broadly oval or obovate, veins prominent, leaves usually in clusters at the ends of the branches: Pagoda Dogwood * * * Margins slightly indented * * * * Obliquely heart-shaped: Linden * * * * Obliquely oval: Elm * * * * Obliquely ovate: Hackberry * * * * Oval or ovate, doubly serrate: Birch (see Betula classification), American Hornbeam * * * * Repand with spiny teeth: American Holly * * * * Coarsely-toothed, twigs bearing thorns: Black locust * * * * Of quivering habit, petioles compressed: Poplar * * * * Long, slender, finely serrate: Willow * * * * Coarsely crenately-toothed: Chestnut oak * * * * Obovate or oval; wavy-toothed: Witch-hazel * * * * Serrate: Plum, Cherry, Crabapple, Sourwood, Juneberry, Silverbell, Beech * * * Margins lobed * * * * Lobes entire * * * * * Apex truncate, three-lobed: Tulip tree * * * * * Lobes and sinuses rounded: White oak * * * * * Lobes rounded, lobes 2 or 3: Sassafras * * * * * Lobed or coarsely toothed, under surface covered with white down: White Poplar * * * * Lobes slightly indented * * * * * Five-lobed, finely serrate: American Sweetgum * * * * * Variously lobed, irregularly toothed: Mulberry * * * * Lobes coarsely toothed * * * * * Irregularly toothed, lobes bristle pointed: Northern Red Oak * * * * * Leaf broad, lobes coarsely toothed: American sycamore * * Leaves are opposite along stem * * * Margins entire * * * * Ovate, veins prominent: Flowering dogwood * * * * Heart-shaped, large: Catalpa * * * * Oval: Fringe tree * * * Margins serrate: Sweet viburnum, Black haw (Viburnum prunifolium) * * * Margins lobed: Maple * Compound leaves * * Leaves pinnately compound * * * Alternate * * * * Margin of leaflets entire * * * * * Leaflets oval, apex obtuse: Black locust * * * * * Leaflets oblong apex acute: Poison sumac * * * * * Leaflets oval or ovate: Yellowwood (Cladrastis kentukea) * * * * * Leaflets ovate — three in number: Hoptree (''Ptelea trifoliata'') * * * * Margin of leaflets with two or three teeth at base: Tree of heaven (Ailanthus) * * * * Margin of leaflets serrate: Sumac, Rowan, Walnut, Hickory * * * Opposite * * * * Margin of leaflets entire: Ash * * * * Margin of leaflets serrate: Ash * * * * Margin of leaflets coarsely toothed: Boxelder Maple * * Leaves bi-pinnately compound * * * Margins of leaflets entire: Kentucky coffeetree * * * Irregularly bi-pinnate, margins of leaflets entire, thorns on stems above the axils of the leaves: honey locust * * * Margins of leaflets serrate, stems spiny: Prickly Ash * * Leaves palmately compound: Ohio Buckeye, Common Horse-chestnut == See also == * Identification key * Leaf shape 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「Identification of trees of the northeastern United States」の詳細全文を読む スポンサード リンク
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