平当树Paradombeya sinensis Dunn
平当树Paradombeya sinensis Dunn
1.平当树（植物分类学报）图版51
Paradombeya sinensis Dunn in Hook. f. Ic. Pl. 4th. ser. 28: Pl. 2743b. 1902.——Paradombeya szechuenica Hu in Bull. Fan Mem. Inst. Biol. 7: 215. 1936-1937. Paradombeya rehderiana Hu in Bull, Fan Mem. Inst. Biol. 10: 145. 1940.
小乔木或灌木，高达5米；小枝柔弱，被稀疏的星状短柔毛。叶膜质，卵状披针形至椭几圆状倒披针形，长5-12.5厘米，宽1.5-5厘米，顶端长渐尖，基部圆形或近浅心形，边缘有密的小锯齿，上面无毛或几无毛，下面被稀疏的星状柔毛，茎生脉3条，侧脉约10对；叶柄长3-5毫米或无柄。花簇生于叶腋；花梗柔弱，长1-1.5厘米；小苞片披针形，早落；萼5裂几至基部，萼片卵状披针形，长4毫米；花瓣5片，黄色，广倒卵形，不相等，长约5毫米，顶端截形，凋而不落；雄蕊15枚，每3枚集合成群并与舌状的退化雄蕊互生，退化雄蕊比花瓣略短；子房圆球形，2室，被星状茸毛。蒴果近圆球形，长2.5毫米，每果瓣有种子1个；种子矩圆状卵形，长1.5毫米，深褐色。花期9-10月。
产云南（泸水）和四川南部（屏山）。生于海拔280-1500米山坡上的稀树灌丛草坡中。
《Flora of China》 Vol. 12 (2007)
Paradombeya sinensis Dunn
平当树 ping dang shu
Paradombeya rehderiana Hu; P. szechuenica Hu.
Small trees or shrubs, up to 5 m tall. Branchlets slender, sparsely stellate puberulent. Petiole 3-5 mm or leaf sessile; leaf blade ovate-lanceolate to elliptic-oblanceolate, 5-12.5 × 1.5-5 cm, membranous, abaxially sparsely stellate hairy, adaxially glabrous or nearly so, basal veins 3, lateral veins ca. 10 on each side of midrib, base rounded or shallowly cordate, margin
densely serrulate, apex long acuminate. Inflorescence a fascicle of 1-3 umbel-like cymes, each 1-6-flowered; pedicels slender, 1-1.5 cm; epicalyx lobes 3, lanceolate, caducous. Calyx lobes ovate-lanceolate, ca. 4 mm. Petals yellow, broadly obovate, unequal to each other, ca. 5 mm, apex truncate, persistent. Staminodes tongue-shaped, slightly shorter than petals. Ovary globose, 2-loculed, densely stellate tomentose; style subulate, glabrous. Capsule nearly globose, ca. 2.5 mm. Seeds dark brown, oblong-ovoid, ca. 1.5 mm.
● Open scrub on grassy slopes; 300-1500 m. S and SW Sichuan, Yunnan.
科名：梧桐科 Sterculiaceae
属名：平当树属 Paradombeya
1.平当树（植物分类学报）图版51
Paradombeya sinensis Dunn in Hook. f. Ic. Pl. 4th. ser. 28: Pl. 2743b. 1902.——Paradombeya szechuenica Hu in Bull. Fan Mem. Inst. Biol. 7: 215. 1936-1937. Paradombeya rehderiana Hu in Bull, Fan Mem. Inst. Biol. 10: 145. 1940.
小乔木或灌木，高达5米；小枝柔弱，被稀疏的星状短柔毛。叶膜质，卵状披针形至椭几圆状倒披针形，长5-12.5厘米，宽1.5-5厘米，顶端长渐尖，基部圆形或近浅心形，边缘有密的小锯齿，上面无毛或几无毛，下面被稀疏的星状柔毛，茎生脉3条，侧脉约10对；叶柄长3-5毫米或无柄。花簇生于叶腋；花梗柔弱，长1-1.5厘米；小苞片披针形，早落；萼5裂几至基部，萼片卵状披针形，长4毫米；花瓣5片，黄色，广倒卵形，不相等，长约5毫米，顶端截形，凋而不落；雄蕊15枚，每3枚集合成群并与舌状的退化雄蕊互生，退化雄蕊比花瓣略短；子房圆球形，2室，被星状茸毛。蒴果近圆球形，长2.5毫米，每果瓣有种子1个；种子矩圆状卵形，长1.5毫米，深褐色。花期9-10月。
产云南（泸水）和四川南部（屏山）。生于海拔280-1500米山坡上的稀树灌丛草坡中。
《Flora of China》 Vol. 12 (2007)
Paradombeya sinensis Dunn
平当树 ping dang shu
Paradombeya rehderiana Hu; P. szechuenica Hu.
Small trees or shrubs, up to 5 m tall. Branchlets slender, sparsely stellate puberulent. Petiole 3-5 mm or leaf sessile; leaf blade ovate-lanceolate to elliptic-oblanceolate, 5-12.5 × 1.5-5 cm, membranous, abaxially sparsely stellate hairy, adaxially glabrous or nearly so, basal veins 3, lateral veins ca. 10 on each side of midrib, base rounded or shallowly cordate, margin
densely serrulate, apex long acuminate. Inflorescence a fascicle of 1-3 umbel-like cymes, each 1-6-flowered; pedicels slender, 1-1.5 cm; epicalyx lobes 3, lanceolate, caducous. Calyx lobes ovate-lanceolate, ca. 4 mm. Petals yellow, broadly obovate, unequal to each other, ca. 5 mm, apex truncate, persistent. Staminodes tongue-shaped, slightly shorter than petals. Ovary globose, 2-loculed, densely stellate tomentose; style subulate, glabrous. Capsule nearly globose, ca. 2.5 mm. Seeds dark brown, oblong-ovoid, ca. 1.5 mm.
● Open scrub on grassy slopes; 300-1500 m. S and SW Sichuan, Yunnan.