Slender, heterophyllous, root-climbing liane to 3 m. Shoot system architecture unclear; eocaul not observed; seedling shingle-leaved; flowering shoot much abbreviated to rarely rather elongated through reiteration, (foliage) leafless or, occasionally, bearing undersize foliage leaves. LEAVES mid-green, paler abaxially, drying mid-green to brown, stiffly coriaceous; petiole 2–10.5 × 0.1–0.6 cm, slender, canaliculate, rounded abaxially, base decurrent, apex prominently geniculate, sheath distinct, prominent, erect, apically ligulate in young growth, ligule later disintegrating; blade 8–26 × 1.6–9.5 cm, broadly to narrowly oblong elliptic, apex acuminate to long-acuminate, apiculate, apicule later deciduous, base obtuse; primary lateral veins arising at 45–70°, 2 intramarginal veins per side, 2–13 mm from blade margin, arising from just above base of the midrib, remaining ± parallel to margin, terminating at the tip of the blade. INFLORESCENCE solitary to several at different stages on a reiterating flowering shoot; peduncle 2.5–6.5 × 0.1–0.4 cm, somewhat robust, strongly curving or straight, the inflorescence held erect, mid-green. Spathe 3.4–6.7 × c. 1 cm, linear-triangular to narrowly oblong, base rounded, annularly inserted on to peduncle, apex acuminate, slightly rough, pale brown tinged reddish pink. Spadix stipitate; stipe 3–19 × 1–2 mm, terete; fertile portion 3.5–13.5 × 0.5–0.3 cm, very slender-cylindric, occasionally sterile at the tip, pale greyish pink, older inflorescences blackish red. Flowers c. 1.6 mm diam., widely scattered, arranged in a lax spiral along the spadix with 6 free tepals and 6 stamens. INFRUCTESCENCE with few to many berries; fruit 6–11 × 5–7 mm, ellipsoid to oblong-ellipsoid; seeds not observed.
Plant usually unifoliate; spathe tube white-green, unstriped outside and inside; spathe mouth margins widely recurved and light green; spathe limb plain carmine outside, paler inside, with a white spot at throat level surrounded by light green margins; spadix appendix smooth and glabrous inside the tube.
Pothos curtisii is the only species of the luzonensis group (see Boyce & Hay 1998) occurring in Thailand. Fertile material is unmistakable by the slender spadix and scattered flowers. Sterile specimens may be confused with other species of the Allopothos supergroup, especially those occurring in the same region of peninsular Thailand (e.g. P. kingii and P. leptostachyus). Pothos leptostachyus and P. kingii have thinly chartaceous leaves, while P. curtisii has more coriaceous leaves.