台湾桤木Alnus formosana (Burkill) Makino
台湾桤木Alnus formosana (Burkill) Makino
2.台湾桤木（中国森林树木图志）
Alnus formosana Makino, Pot. Mag. Tokyo 26: 390. 1912; Kanehira, Formos. Trees ed. 2. 83. fig. 38. 1936;胡先骕, 中国森林树木图志2: 57.图版22. 1948; Li Hui-lin, Flora of Taiwan 2: 43. Pl. 204. 1976. ——Alnus maritima (Marsh.) Nutt. var. japonica Regel in DC., Prodr. 16 (2): 186. 1868. quoad pl. formosa. ——Alnus maritima (Marsh.) Nutt. var. formosana Burk. in Journ. Linn. Soc. Bot. 26: 500. 1899. ——Alnus japonica (Thunb.) Steud. var. formo. sana Callier in Fedde, Repert. Spec. Nov. 10: 228. 1911. ——Alnus maritima auct. non (Marsh.) Nutt. : Steenis, Fl. Malesiana 5 (2): 207. 1955. p. p. quoad syn. var. formosanam H. Winkl. et A. formosanam Makino ——Alnus japonica auct. non Steud. : Li Hui-lin, Woody Fl. Taiwan 80. f. 24. 1963. p. p. quoad syn. A. fomosanam.
大乔木，高可达20米；树皮暗灰褐色；枝条紫褐色，无毛，具条棱；小枝疏被短柔毛；芽具柄，卵形，具两枚芽鳞。叶椭圆形至矩圆披针形，较少卵状矩圆形，长6-12厘米，宽2-5厘米，顶端渐尖或锐尖，基部圆形或宽楔形，边缘具不规则的细锯齿，两面均近无毛，有时下面的脉腋间具稀疏的髯毛，侧脉6-7对；叶柄细瘦，长1.2-2.2厘米，沿沟槽密被褐色短柔毛。雄花序春季开放，3-4枚并生，长约7厘米，苞鳞无毛。果序1-4枚，排成总状，椭圆形，长1.5-2.5厘米; 总梗长约1.5厘米；序梗长3-5毫米，均较粗壮；果苞长3-4毫米，顶端5浅裂。小坚果倒卵形，长2-3毫米，具厚纸质的翅，翅宽及果的1/4-1/3。
我国台湾特有种，在省内分布普遍。常生于河岸两旁，有时成纯林。模式标本采自淡水县。
《Flora of China》 Vol. 4 (1999)
Alnus formosana (Burkill) Makino
台湾桤木 tai wan qi mu
Alnus maritima (Marshall) Nuttall var. formosana Burkill in F. B. Forbes & Hemsley, J. Linn. Soc., Bot. 26: 500. 1899; A. japonica (Thunberg) Steudel var. formosana Callier.
Trees to 20 m tall; bark dark gray-brown. Branches purplish brown, glabrous, striate; branchlets sparsely pubescent. Buds stipitate, with 2 glabrous, ribbed scales. Petiole 1.2-2.2 cm, slender, densely pubescent in furrow; leaf blade elliptic or oblong-lanceolate, rarely ovate-oblong, 6-12 × 2-5 cm, abaxially bearded in axils of lateral veins, adaxially subglabrous, base rounded or broadly cuneate, margin irregularly minutely serrate, apex acuminate or acute; lateral veins 6 or 7 on each side of midvein. Female inflorescence 1, or 2-4 in a raceme, ellipsoid, 1-2.5 cm; peduncle 3-5 mm, robust; bracts 3-4 mm, woody, base cuneate, apex rounded, 5-lobed. Nutlet obovate, 2-3 mm, with papery wings 1/4-1/3 as wide as nutlet. Fl. May-Jun, fr. Jul-Sep.
* Riverbanks, forming pure stands, common; near sea level to 2900 m. Taiwan (Tanshui)
别名：台湾赤杨;水柯仔;水柳柯;
科名：桦木科 Betulaceae
属名：桤木属 Alnus
2.台湾桤木（中国森林树木图志）
Alnus formosana Makino, Pot. Mag. Tokyo 26: 390. 1912; Kanehira, Formos. Trees ed. 2. 83. fig. 38. 1936;胡先骕, 中国森林树木图志2: 57.图版22. 1948; Li Hui-lin, Flora of Taiwan 2: 43. Pl. 204. 1976. ——Alnus maritima (Marsh.) Nutt. var. japonica Regel in DC., Prodr. 16 (2): 186. 1868. quoad pl. formosa. ——Alnus maritima (Marsh.) Nutt. var. formosana Burk. in Journ. Linn. Soc. Bot. 26: 500. 1899. ——Alnus japonica (Thunb.) Steud. var. formo. sana Callier in Fedde, Repert. Spec. Nov. 10: 228. 1911. ——Alnus maritima auct. non (Marsh.) Nutt. : Steenis, Fl. Malesiana 5 (2): 207. 1955. p. p. quoad syn. var. formosanam H. Winkl. et A. formosanam Makino ——Alnus japonica auct. non Steud. : Li Hui-lin, Woody Fl. Taiwan 80. f. 24. 1963. p. p. quoad syn. A. fomosanam.
大乔木，高可达20米；树皮暗灰褐色；枝条紫褐色，无毛，具条棱；小枝疏被短柔毛；芽具柄，卵形，具两枚芽鳞。叶椭圆形至矩圆披针形，较少卵状矩圆形，长6-12厘米，宽2-5厘米，顶端渐尖或锐尖，基部圆形或宽楔形，边缘具不规则的细锯齿，两面均近无毛，有时下面的脉腋间具稀疏的髯毛，侧脉6-7对；叶柄细瘦，长1.2-2.2厘米，沿沟槽密被褐色短柔毛。雄花序春季开放，3-4枚并生，长约7厘米，苞鳞无毛。果序1-4枚，排成总状，椭圆形，长1.5-2.5厘米; 总梗长约1.5厘米；序梗长3-5毫米，均较粗壮；果苞长3-4毫米，顶端5浅裂。小坚果倒卵形，长2-3毫米，具厚纸质的翅，翅宽及果的1/4-1/3。
我国台湾特有种，在省内分布普遍。常生于河岸两旁，有时成纯林。模式标本采自淡水县。
《Flora of China》 Vol. 4 (1999)
Alnus formosana (Burkill) Makino
台湾桤木 tai wan qi mu
Alnus maritima (Marshall) Nuttall var. formosana Burkill in F. B. Forbes & Hemsley, J. Linn. Soc., Bot. 26: 500. 1899; A. japonica (Thunberg) Steudel var. formosana Callier.
Trees to 20 m tall; bark dark gray-brown. Branches purplish brown, glabrous, striate; branchlets sparsely pubescent. Buds stipitate, with 2 glabrous, ribbed scales. Petiole 1.2-2.2 cm, slender, densely pubescent in furrow; leaf blade elliptic or oblong-lanceolate, rarely ovate-oblong, 6-12 × 2-5 cm, abaxially bearded in axils of lateral veins, adaxially subglabrous, base rounded or broadly cuneate, margin irregularly minutely serrate, apex acuminate or acute; lateral veins 6 or 7 on each side of midvein. Female inflorescence 1, or 2-4 in a raceme, ellipsoid, 1-2.5 cm; peduncle 3-5 mm, robust; bracts 3-4 mm, woody, base cuneate, apex rounded, 5-lobed. Nutlet obovate, 2-3 mm, with papery wings 1/4-1/3 as wide as nutlet. Fl. May-Jun, fr. Jul-Sep.
* Riverbanks, forming pure stands, common; near sea level to 2900 m. Taiwan (Tanshui)