Stem slightly compressed cylindrical, upper thin, 2 internodes above the base enlarged fusiform ; the stem diameter of the swollen part is about 0.5-1cm, often with longitudinal ribs.

Leaves flattened, alternate in two columns in middle stem, leathery, ovate- oblong, ca. 2.8-5.3 cm long, ca. 4-9 mm wide, apex obtuse or acute and few slightly in two columns, base with sheath holding stem.

Flowers : Flowers from the part or a few of the leaves on the stem are opposite to the leaves, usually solitary, white, with aroma ; with several bracts ; pedicel and ovary are light grass green, about 6 mm long ; flowers spreading, middle sepals sword-shaped, about 6-7mm long, about 2-3mm wide, apex acute ; petals obliquely lanceolate, about 6mm long, 1-2mm wide, apex subacuminate ; lateral sepals nearly oblique triangle, about 7-8mm long, about 3-4mm wide, apex acute ; the lip is 3-lobed, the lateral lobe is upright, nearly crescent-shaped, and there are purple fork veins on both sides of the lobe, and the apex is nearly round ; middle lobe nearly triangular, apex with short tip, margin with fine teeth or wrinkled wave ; lip disc with 1 pale yellow corpus callosum and 3 - lobed ; the calyx sac is oblong, about 6 mm long ; stamens ca. 3 mm, calyx foot base with 1 yellow flesh ; medicine cap white.

Flowering  June.