镇沅石斛 Dendrobium zhenyuanense

Other specimen examined:—CHINA. Yunnan Province: Lincang County, on tree, broad-leaved evergreen forest,1900 m, 27 September 2012, Li 2244 (HITBC!). 

附生草本植物，产云南省临沧县。
植株矮小。茎肉质，纺锤形，长1.0-1.8厘米，直径4-5毫米，具2-3节，当年生的茎被叶鞘包围，以前生的茎裸露，深紫色。
叶二列，2-3枚，互生，在茎下部的比上部的短小，披针形，1.5-2.0×0.4-0.6厘米，先端钝并且不等侧2裂，基部扩大为鞘，鞘口斜截并包围茎。
总状花序花序1-3个，直立，近顶生或侧生在当年茎的上部，通常1.0-1.7厘米，不高出叶外，具数花；轴细长，2厘米长，直径约0.5毫米；花苞片披针形，约1.0-2.0×0.5毫米，膜质，先端锐尖。花绿色，花梗和子房长1-2毫米；中萼片狭卵形，约3.5×1.0毫米，三脉，顶端锐尖；侧萼片卵状三角形，约3.5×1.5毫米，三脉，顶端锐尖，顶端具明显的粘液；萼囊长圆形，长1.0-1.5毫米。花瓣披针形，3×1毫米，三脉，先端锐尖。唇瓣椭圆形，约2.5×1.5毫米，先端锐尖；基部具两个半圆形的片层，顶端多加厚和肉质；蕊柱长约2毫米，基部膨大；药帽顶端边缘稍缺刻。   花期：7-8月。

Epiphytic herbs with smooth roots. Stems fusiform, 1.0–1.8 cm long, 4–5 mm in diam., with 2–3 nodes, current stems enclosed in leaf sheaths, previous stems naked, dark purple. Leaves 2–3, distichous, lowermost smaller than upper, lanceolate, 1.5–2.0 × 0.4–0.6 cm, base dilated into sheaths, mouth of which is obliquely truncate and enclosing the stem, apex obtuse and unequally bilobed. Inflorescences 1–3, subterminal or lateral on upper part of current year’s stem, erect, usually 1.0–1.7 cm, not exceeding leaves, several flowered; rachis slender, 2 cm long, ca. 0.5 mm in diam.; floral bracts lanceolate, ca. 1.0–2.0 ×0.5 mm, membranous, apex acute. Flowers green, pedicel and ovary 1–2 mm long; dorsal sepal narrowly ovate, ca. 3.5 × 1.0 mm, triveined, apex acute; lateral sepals ovate-triangular, ca. 3.5× 1.5mm, triveined, apex acute, tip with a distinct mucro; mentum oblong, 1.0–1.5 mm long. Petals lanceolate, 3 ×1mm, triveined, apex acute. Lip elliptic, ca. 2.5 × 1.5 mm, apex acute; base with two semi-rotund lamellae, tip much thickened and fleshy; column ca. 2 mm long, base dilated; anther cap with apical margin slightly lacerate.