IUCN Red List of Threatened Species https://www.iucnredlist.org/species/199684/9117158
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
CATE Araceae, 17 Dec 2011. araceae.e-monocot.org
Thailand, Mekong River: Laos, southern region of Champasak Province: Cambodia, Kratie Province.
Deciduous herb to 1.3 m tall. Subterranean stem a subglobose, stoloniferous tuber, up to 4 cm across and 2 cm high, white, with stolons to 10 × 1 cm. Pseudostem ca 20 cm long, green, mottled grey and pink. Leaf solitary, exceptionally bifoliate; cataphylls to 20 cm long, purple; petiole to 1 m long, similar in colour to the pseudostem; leaf blade radiate; leaflets 7–11, ovate, 10–20 × 4–6 cm, margins entire, apex acute, ending in an acumen 1 cm long, base cuneate and sessile, leaflets plain green, with impressed veins above, underside paler. Inflorescence held below the foliage; peduncle 5–20 cm long, green and pink mottled; spathe tube cylindrical, 4–6 × 1–1.2 cm, green with thin white stripes, spathe mouth margins recurved; spathe limb lanceolate, 5–8 × 3–4 cm, green, flushed red-brown, ending in a long brown tail to 25 cm long; spadix appendix well exserted from the tube, 5–6 cm long × 3–4 mm wide, pale green, stout, cylindrical, ending in a rounded and rugose apex curving forward; sessile, pistillate inflorescences with green bristles above the fertile part; fertile zone staminate or pistillate, cylindrical, 1.5–2 cm long; staminate flowers loosely arranged; pistillate flowers densely arranged; ovaries bottle-shaped, green; stigma sessile, penicillate, white. Infructescence on an erect peduncle, globose, 3–5 cm; fruits red-orange when ripe, 8–10 × 5–7 mm, top rounded, up to 3 seeds per berry. Seeds globose, 3–4 mm diam.
Cryptocoryne mekongensis grows on river banks that emerge during the dry season from February to April, in partial sun. It can be found sheltered between rocks and big stones or in sheltered places growing in sand and gravel and more or less mud covered. Cryptocoryne mekongensis has been found growing together with different varieties of C. crispatula.
