生活型

tree

形態特徵

• Deciduous trees, buds ovoid, scales mucronate at apex, margins short ciliate, slightly pubescent outside; young branches brown pubescent, soon glabrous.
• Leaves 15-30 cm long, rachis sparsely brown pubescent, later nearly glabrous then; petioles 3-4 cm long, sparsely brown pubescent, nearly glabrous; leaflets 9-19, chartaceous, slightly pubescent on midvein of upper surface, pubescent in axil of lateral veins of lower surface, lateral leaflets sessile, lanceolate-ovate or oblong-lanceolate, 4-11 cm long, 1.5-3.5 cm wide, attenuate to apex, obliquely obtuse or rounded at base, margins serrate, terminal leaflet with petiolule 0.5-2 cm long, attenuate to apex, rounded or cuneate at base.
• Staminate inflorescence 4-10 cm long; staminate flowers with broadly ovate bracts; bracts 2-3 mm long; stamens 6-8. Pistillate inflorescence 1-3 cm long. Pistillate flowers with lanceolate-ovate bracts; bracts stiff, attenuate to apex, 2.5-3 mm long; perianth 2-parted, fused to ovary. Frutescence ovate-ellipsoid or ellipsoid, 2.5-4 cm long, 2-2.5 cm across; persistent bracts woody, deltoid-ovate, 7-10 mm long, acute to acuminate.
• Fruit a nutlet, flattened, narrowly winged, 4-6 mm long, 3-5 mm wide. Seeds ovoid.

分布

• 台灣 : in the forests of the northern and central parts of this island.
• 世界 : Japan, Korea, Vietnam, mainland China.

引證標本

HSINCHU: Kuan-wu, Huang 4122. TAICHUNG: Sung-mao, Hsu 8791; Lishan, Kuo 7651. NANTOU: Tungpu to Patungkuan, Tamura et al. 21920. HUALIEN: Tienhsiang, Yang 0515.

參考文獻

• YANG, YUEN-PO and LU, SHENG-YOU, Flora of Taiwan, second edition 2: 25. 1996.  (Fl. Taiwan 2nd edit.)