Pothos species in Thailand and Indochina fall into three distinct, though parapatric, geographical units (Boyce 1996). Two of the 14 species, P. chinensis (Raf.) Merr. and P. scandens L., have a Indohimalayan distribution, occurring more-or-less continuously from the eastern Himalaya (as far west as Nepal) to southern China (east to Hong Kong and north to Hubei) and south to peninsular Thailand. However, the distribution of P. scandens occurs throughout Indomalesia east to the Philippines and extends south and west to Madagascar.
Seven species (P. dzui P.C. Boyce, P. gigantipes Buchet ex. P.C. Boyce, P. grandis Buchet ex. P.C. Boyce & D.V. Nguyen, P. kerrii Buchet ex P.C. Boyce, P. pilulifer Buchet ex. P.C. Boyce, P. repens (Lour.) Druce and P. touranensis Gagnep.) are restricted to Vietnam, Lao P.D.R., southern China and possibly Cambodia (P. gigantipes). Based on inflorescence morphology, relationships of outside the region appear to be with Javan P. junghuhnii de Vriese [P. grandis, P. gigantipes, P. kerrii, P. pilulifer and possibly P. dzui], the Malesian complex of P. barberianus [P. touranensis] and Sulawesi/Philippines P. cylindricus Presl [ P. repens and maybe P. dzui].
Four species (P. kingii Hook.f., P. lorispathus Ridl., P. macrocephalus Scort. ex Hook.f. and P. curtisii Hook.f.) occur widely in Peninsular Malaysia (P. curtisii and P. macrocephalus also reach Sumatera) and their range in the review area is restricted to the southernmost provinces of peninsular Thailand where they are confined to limestone (P. lorispathus, P. macrocephalus) and granite (P. kingii, P. curtisii).
One species, P. lancifolius Hook.f., has a curious disjunct distribution with sites in Peninsular Malaysia and southern central Vietnam (where it has been called hitherto P. penicilliger Gagnep.). Relationships with other species outside the area are not clear although an as yet undescribed species similar to P. lancifolius is found in Borneo.