青榨槭
分类:植物科普
青榨槭 Acer davidii Franch.
青榨槭花期
青榨槭叶片
青榨槭果期
落叶乔木，高约10-15米，稀达20米。树皮黑褐色或灰褐色，常纵裂成蛇皮状。小枝细瘦，圆柱形，无毛；当年生的嫩枝紫绿色或绿褐色，具很稀疏的皮孔，多年生的老枝黄褐色或灰褐色。冬芽腋生，长卵圆形，绿褐色，长约4-8毫米；鳞片的外侧无毛。叶纸质，外貌长圆卵形或近于长圆形，长6-14厘米，宽4-9厘米，先端锐尖或渐尖，常有尖尾，基部近于心脏形或圆形，边缘具不整齐的钝圆齿；上面深绿色，无毛；下面淡绿色，嫩时沿叶脉被紫褐色的短柔毛，渐老成无毛状；主脉在上面显著，在下面凸起，侧脉11-12对，成羽状，在上面微现，在下面显著；叶柄细瘦，长约2-8厘米，嫩时被红褐色短柔毛，渐老则脱落。花黄绿色，杂性，雄花与两性花同株，成下垂的总状花序，顶生于着叶的嫩枝，开花与嫩叶的生长大约同时，雄花的花梗长3-5毫米，通常9-12朵常成长4-7厘米的总状花序；两性花的花梗长1-1.5厘米，通常15-30朵常成长7-12厘米的总状花序；萼片5，椭圆形，先端微钝，长约4毫米；花瓣5，倒卵形，先端圆形，与萼片等长；雄蕊8，无毛，在雄花中略长于花瓣，在两性花中不发育，花药黄色，球形，花盘无毛，现裂纹，位于雄蕊内侧，子房被红褐色的短柔毛，在雄花中不发育。花柱无毛，细瘦，柱头反卷。翅果嫩时淡绿色，成熟后黄褐色；翅宽约1-1.5厘米，连同小坚果共长2.5-3厘米，展开成钝角或几成水平。花期4月，果期9月。
产华北、华东、中南、西南各省区。在黄河流域长江流域和东南沿海各省区，常生于海拔500-1500米的疏林中。模式标本采自四川宝兴。
本种生长迅速，树冠整齐，可用为绿化和造林树种。树皮纤维较长，又含丹宁，可作工业原料。
Trees ca. 10 m tall, andromonoecious, but often with an androdioecious sex expression. Bark gray-brown. Branchlets brownish green or greenish purple, glabrous; winter buds oblong, small, glabrous, scales 2 pairs. Leaves deciduous; petioles 3-6 cm, rufous pubescent when young; leaf blade abaxially pale green, adaxially dark green, ovate, ovate-oblong, or suborbicular-ovate, (6-)8-12(-14) × (4-)5-8(-9) cm, papery, abaxially rufous pubescent on veins when young, glabrescent when mature, adaxially glabrous, veins 10-13 pairs, base subcordate or rounded, margin undivided or (3 or)5-lobed, serrulate or doubly serrate, apex acuminate or rarely caudate-acuminate; lobes apically obtuse or middle lobe triangular and lateral and basal lobes apically acute. Flowers greenish yellow. Inflorescence pendulous, racemose. Pedicel 1-1.5 cm, slender. Sepals 5, elliptic, ca. 4 mm, apex obtuse. Petals 5, obovate, ca. 4 mm. Stamens 8, ca. 3 mm, glabrous; anthers yellow. Disk glabrous, lobes intrastaminal. Ovary rudimentary. Fruit brownish yellow; nutlets flat, 8-10 × ca. 6 mm; wing including nutlet 2.5-2.8 cm, wings spreading horizontally or obtusely. Fl. Mar-Apr, fr. Sep. 2n = 26.
Mixed forests. Anhui, Fujian, SE Gansu, Guangdong, Guangxi, Guizhou, Hebei, Henan, Hubei, Hunan, Jiangsu, Jiangxi, Ningxia, S Shaanxi, Shanxi, Sichuan, Yunnan, Zhejiang [Myanmar].
This species is ornamental for its snakelike bark and the autumn coloration of its leaves.
