景洪石斛Dendrobium exile

中文名Chinese Name):景洪石斛
学名Scientific Name):Dendrobium exile Schltr.
英文名English Common Name):
别名Chinese Common Name):
异名Synonym):Aporum heterocaulon (Guillaumin) Rauschert  Ceraia exilis (Schltr.) M.A.Clem.  Dendrobium heterocaulon Guillaumin
科属(Family & Genus):兰科(Orchidaceae)石斛属
形态特征(Description):茎直立,细圆柱形,多少木质化,长达50厘米,粗约3毫米,上部常分枝,基部上方2-3个节间膨大呈纺锤形;膨大部分的茎肉质,长4.5厘米,粗约8毫米,具4个棱,幼时被浅白色的膜质鞘,老时赤褐色并且具光泽。叶通常互生于分枝的上部,直立,扁压状圆柱形,长2.5-6厘米,宽1.5-2.5毫米,先端锐尖,基部具革质鞘。花序减退为单朵花,侧生于分枝的顶端,白色,开展;花苞片卵形,长约2毫米,先端钝尖;花梗和子房纤细,长约1厘米;萼片和花瓣近披针形,先端长渐尖;中萼片长1.7厘米,宽约2.5毫米,具5条脉;侧萼片约等大于中萼片,基部歪斜与蕊柱足形成角状的萼囊;萼囊劲直,朝上,长约1厘米,末端急尖;花瓣长1.7厘米,宽1.5毫米,具3条脉;唇瓣基部楔形,中部以上3裂;侧裂片斜半卵状三角,内面具少数淡紫色斑点,先端钝,前端边缘波状;中裂片狭长圆形,先端急尖,边缘波状;唇盘黄色,被稀疏的长柔毛,从基部至先端纵贯3条龙骨脊;蕊柱长2毫米,蕊柱足近基部具1个胼胝体;药帽圆锥形。蒴果纺锤形,长4厘米,粗6毫米。花期10-11月,果期11-12月。
分布Distribution):产云南南部(景洪、勐腊)。生于海拔600-800米的疏林中树干上。越南、泰国也有。
用途Use):
引自中国植物志英文版FOC Vol. 25 Page 369, 396
Dendrobium exile Schlechter, Repert. Spec. Nov. Regni Veg. 2: 85. 1906.
景洪石斛 jing hong shi hu | Orchidaceae  | Dendrobium
Ceraia exilis (Schlechter) M. A. Clements.
Stems erect, upper part branched, cylindric, to 50 cm, slender, ca. 3 mm in diam., 2 or 3 internodes above base dilated and fusiform; dilated portion of stems ca. 4.5 cm, ca. 8 mm in diam., fleshy, with 4 ribs, with pale white membranous sheaths when young, reddish brown and glossy when old. Leaves often alternate on upper part of branches, erect, terete, 2.5-6 × 1.5-2.5(or more) cm, base with leathery sheaths, apex acute. Inflorescence axillary on leafy older stems, 1-flowered, up to 4 flowers open at once per stem; floral bracts ovate, ca. 2 mm. Pedicel and ovary ca. 1 cm, slender. Flowers spreading, white, inner surface of lip lateral lobes with a few pale purple spots, disk yellow. Dorsal sepal sublanceolate, ca. 17 × 2.5 mm, 5-veined, long acuminate; lateral sepals similar to and ca. as large as dorsal sepal; mentum rigid, ca. 1 cm, acute. Petals similar to sepals, ca. 17 × 1.5 mm, 3-veined; lip cuneate at base, 3-lobed above middle; lateral lobes obliquely subovate-triangular, front margin undulate, apex obtuse; mid-lobe narrowly oblong, margin undulate, apex acute; disk sparsely villous, with 3 thick and stout keeled ridges from base to apex. Column ca. 2 mm, foot with a basal callus; anther cap conic. Capsule fusiform, ca. 4 × 0.6 cm.
Epiphytic on tree trunks in open forests; 600-800 m. S Yunnan (Jinghong, Mengla) [Thailand, Vietnam].
景洪石斛Dendrobium exile

景洪石斛Dendrobium exile(责任编辑:徐晔春)

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