圆叶乌桕Triadica rotundifolia

中文名(Chinese Name):圆叶乌桕
学名(Scientific Name):Triadica rotundifolia (Hemsley) Esser
英文名(English Common Name):
别名(Chinese Common Name):大叶乌桕、圆叶桕木
异名(Synonym):Sapium rotundifolium Hemsl.  Baccaurea esquirolii H.Lév.
科属(Family & Genus):大戟科(Euphorbiaceae)乌桕属
形态特征Description):灌木或乔木,高3-12米,全部无毛;小枝粗壮而节间甚短。叶互生,厚,近革质,叶片近圆形,长5-11厘米,宽6-12厘米,顶端圆,稀凸尖,亦偶有不同深浅的凹缺者,基部圆、截平至微心形,全缘,腹面绿色,背面苍白色;中脉在背面显著凸起,侧脉10-15对,从中脉平展发出或略向上弯拱,离缘4-6毫米网结,网脉明显;叶柄圆柱形,纤细,长3-7厘米,顶端具2腺体;托叶小,腺体状,长常为宽的1/2。花单性,雌雄同株,密集成顶生的总状花序,雌花生于花序轴下部,雄花生于花序轴上部或有时整个花序全为雄花。雄花:花梗圆柱形,长1-3毫米;苞片卵形,长和宽近相等约2毫米,顶端锐尖,边缘流苏状,基部两则各具1腺体,每一苞片内有3-6朵花;小苞片狭卵形,长和宽近相等约0.8毫米,顶端撕裂状;花萼杯状,3浅裂,裂片圆,有细齿;雄蕊2枚,罕为1或3枚,花药圆形,花丝极短。雌花:花梗比雄花的粗壮,长约2毫米,苞片与雄花的相似,每一苞片内仅有1朵花;花萼3深裂几达基部,裂片阔卵形,宽1-1.2毫米,顶端短尖,边缘具细齿;子房卵形,花柱3,基部合生,柱头外卷。蒴果近球形,直径约1. 5厘米;分果爿木质,自宿存的三角柱状的中轴上脱落;种子久悬于中轴上,扁球形,直径约5毫米,顶端具一雅致的小凸点,腹面具1纵棱,外面薄被蜡质的假种皮。花期4-6月。
分布(Distribution):分布于云南、贵州、广西、广东和湖南。喜生于阳光充足的石灰岩山地。越南北部也有。
用途(Use):
引自中国植物志英文版FOC Vol. 11 Page 284, 285
Triadica rotundifolia (Hemsley) Esser, Harvard Pap. Bot. 7: 19. 2002.
圆叶乌桕 yuan ye wu jiu  | Euphorbiaceae  | Triadica
Sapium rotundifolium Hemsley, J. Linn. Soc., Bot. 26: 445. 1891; Baccaurea esquirolii H. Léveillé; S. rotundifolium var. obcordatum S. K. Lee.
Trees up to 12 m tall, glabrous; branchlets robust. Leaves alternate; stipules small, glandular, caducous; petioles 3-7 cm, with 1 gland at apex; leaf blade subrotund, 5-11 × 6-12 cm, base rounded to shallowly cordate, margin entire, apex rounded, rarely acute or incised; lateral veins 10-15 pairs. Flowers unisexual, monoecious, densely fascicled in terminal racemes, female in lower part, male in upper part, sometimes male throughout. Male flowers: pedicels cylindric, 1-3 mm; bracts ovate, ca. 2 × 2 mm, margins fimbriate, base bilateral, each with 1 gland; bracteoles narrowly ovate, less than 1 mm; calyx cupular, shallowly 3-lobed; stamens (1 or)2(or 3); filaments shorter; anthers subglobose. Female flowers: pedicels robust, ca. 2 mm; calyx 3-lobed, lobes broadly ovate, ca. 1 mm, margins serrulate; ovary ovate, 3-lobed; styles 3, connate at base; stigma revolute. Capsules subglobose, 8-10 mm in diam. Seeds oblate, ca. 5 mm in diam., with waxy arils. Fl. Apr-Jun, fr. Jul-Oct.
Limestone montane forests; 100-500 m. Guangdong, Guangxi, Guizhou, Hunan, Yunnan [N Vietnam].
 圆叶乌桕Triadica rotundifolia

圆叶乌桕Triadica rotundifolia
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