Ophiorrhiza oppositiflora

Herbs, up to 70 cm tall; stems terete, hispidulous to glabrescent. Leaves simple, opposite decussate; petiole ca. 1-2 cm, subglabrous or puberulent; stipules ca. 0.2-1.1 cm, caducous or persistent on upper nodes, linear or bifid, puberulent; lamina ca. 3-15 × 1-6 cm, narrowly elliptic, ovate, or lanceolate, cuneate then narrowed and shortly decurrent at base, shortly acuminate at apex, entire, chartaceous, brown, subglabrous or sparsely strigillose adaxially, pilose along principal veins abaxially; secondary nerves 9-15 pairs. Inflorescence terminal and/or paired in upper stem nodes, cymose to paniculate, many flowered, ferruginous puberulent; peduncle ca. 2-4 cm; axes helicoid; bracts minute, caducous; Flowers subsessile; calyx pubescent; hypanthium ellipsoid, ca. 0.1 cm; lobes triangular, ca. 0.3 mm; corolla white, tubular-funnelform, outside glabrous; tube ca. 0.8 cm, inside glabrous or densely barbate in throat; lobes oblong-triangular, ca. 0.2 cm, dorsally ridged, apex rostrate. Capsules drying yellow, mitriform-obcordate, ca. 0.2 × 0.6-0.7 cm, subglabrous. 

References:

Catalogue of Life  The Plant List Ver.1.1  WCSP  Flora of China  Tropicos  India Biodiversity Portal