IUCN Red List of Threatened Species https://www.iucnredlist.org/species/193510/2240326
Extinction risk predictions for the world's flowering plants to support their conservation (2024). Bachman, S.P., Brown, M.J.M., Leão, T.C.C., Lughadha, E.N., Walker, B.E. https://nph.onlinelibrary.wiley.com/doi/full/10.1111/nph.19592
North-east Thailand only; up to c. 1000 m altitude.
A terrestrial herb with thick pubescent roots. Leaves 3–4, narrowly oblong-elliptic, acute at tridenticulate apex, up to 13 cm long, 3–4.5 cm broad, tessellated dark green and yellow-green above. Inflorescence 1-flowered; scape purple, covered with fine white hairs; bract lanceolate, acute, 1.8–2 cm long, 0.9 cm broad, green, pubescent. Flower 11–14.3 cm across; ovary and pedicel 3.5–6 cm long, green, pubescent. Dorsal sepal concave, ovate, acuminate, 3.8–5.4 cm long, 2.6–4.4 cm broad, ciliate, pubescent on outside, white, veined with green and spotted purple at base. Synsepal lanceolate, acuminate, 3.4–4.2 cm long, 1.6–2.6 cm broad, similar in coloration and indumentum to dorsal. Petals subhorizontal, oblong-ligulate to oblanceolate, acute, 5.4–7.3 cm long, 1.5–2.4 cm broad, green heavily spotted with maroon, margins ciliate. Lip saccate, 4.8–6.1 cm long, 2.3–3.2 cm broad, green heavily flushed and veined maroon, warty on side-lobes. Column pale green, 5 mm long. Staminode with a tridentate lower margin with incurved acute lateral teeth, 8 mm tall, 11 mm broad, pubescent. 2n = 40.
