美国山核桃Carya illinoensis (Wangenheim) K. Koch

别名：pecan;薄壳山核桃;薄皮山核桃;

科名：胡桃科 Juglandaceae

属名：山核桃属 Carya

《中国植物志》第21卷042页
  5.美国山核桃（中国树木分类学）薄壳山核桃（植物分类学报）图版11：8
  Carya illinoensis (Wangenh.) K. Koch, Dendr. 1: 593. 1869; Rehd. inJourn. Arn. Arb. 22: 571. 1941 ——Juglans pecan Marsh., Arbust. Am. 69. 1785, nom. subnud. ——J. illinoinensis Wangenh., Beitr. Teutsch. Holzger. For. stwiss. Nordam. Holz. 54, t. 18. 1787, p. p. excl. fig. fruct., descr. fruct.——Carya pecan (Marsh.) Engl. et Graebn. in Notizbl. Bot. Gart. Mus. Berlin 3 App. 9: 19. 1902;陈嵘, 中国树木分类学143, 图105. 1937.
  大乔木，高可达50米，胸径可达2米，树皮粗糙，深纵裂。芽黄褐色，被柔毛，芽鳞镊合状排列。小枝被柔毛，后来变无毛，灰褐色，具稀疏皮孔。奇数羽状复叶长25-35厘米，叶柄及叶轴初被柔毛，后来几乎无毛，具9-17枚小叶；小叶具极短的小叶柄，卵状披针形至长椭圆状披针形、有时成长椭圆形，通常稍成镰状弯曲，长7-18厘米，宽2.5-4厘米，基部歪斜阔楔一形或近圆形，顶端渐尖，边缘具单锯齿或重锯齿，初被腺体及柔毛，后来毛脱落而常在脉上有疏毛。雄性葇荑花序3条1束，几乎无总梗，长8-14厘米，自去年生小枝顶端或当年生小枝基部的叶痕腋内生出。雄蕊的花药有毛。雌性穗状花序直立，花序轴密被柔毛，具3-10雌花。雌花子房长卵形，总苞的裂片有毛。果实矩圆状或长椭圆形，长3-5厘米，直径2.2厘米左右，有4条纵棱，外果皮4瓣裂，革质，内果皮平滑，灰褐色，有暗褐色斑点，顶端有黑色条纹；基部不完全2室。5月开花，9-11月果成熟。
  原产北美洲；我国河北、河南、江苏、浙江、福建、江西、湖南、四川等省有栽培。
  果仁（即种子）含油脂，可食。

《Flora of China》 Vol. 4 (1999)
Carya illinoinensis  (Wangenheim) K. Koch
美国山核桃   mei guo shan he tao
Juglans illinoinensis Wangenheim, Beytr. Teut. Forstwiss. 54. 1787; Hicoria olivaeformis (Michaux) Nuttall; H. pecan (Marshall) Britton; Juglans olivaeformis Michaux; J. pecan Marshall.
Trees to 50 m tall. Terminal buds with 4 or more false-valved scales, yellowish brown. Leaves 25-35 cm; petiole 4-8 cm, glabrous or glabrescent; rachis generally glabrous or glabrescent; leaflets (7 or)9-13(-17), lateral ones shortly petiolulate or sessile, blade ovate-lanceolate to elliptic-lanceolate or long elliptic, 7-18 × 2.5-4 cm, with scattered, peltate scales, abaxially pubescent or glabrescent, base oblique, broadly cuneate or subrounded, apex acuminate; terminal petiolule 5-25 mm. Male spikes 8-14 cm; peduncle nearly absent. Anthers sparsely pilose. Nuts ovoid-ellipsoid, 3-5 × 2-3 cm; husk without prominent wings; shell without longitudinal ridges, ca. 1 mm thick, 2-chambered at base, lacunae present. Fl. May, fr. Sep-Nov. 2n = 32, rarely 64.
Cultivated. Fujian, Hebei, Henan, Hunan, Jiangsu, Jiangxi [native to United States]
Grown extensively in China for its edible nuts.