Rhizome usually forked, ca. 1 cm in diam., fleshy. Stem scandent, 2--3 m or more, rather slender. Leaves alternate or occasionally also opposite, sessile or shortly petiolate, lanceolate to ovate-lanceolate, 7--13 cm, apex long caudate with a tendril. Flowers nodding; pedicel 10--15 cm. Tepals reflexed, bright red, proximally tinged with yellow, linear-oblanceolate, 4.5--5 cm × 7--9 mm, base slightly clawed, margin much crisped. Filaments 3--4 cm; anthers ca. 1 cm. Style 2.5--3.5 cm; stigma lobes 6--7 mm. Fl. Jul--Aug. 2 n = 22, 88, 90.
Flowers turning from yellow to red.
Flowers solitary, axillary, sometimes terminal, different shades of yellow, orange, red, crimson, purple/mauve stripes or fading purple, often bicolored; pedicel erect, recurved apically, 3.5–18 cm long.
Perianth sometimes at the base connate into a short tube, up to 2 mm long; perianth segments (strongly) reflexed, base clawed, narrowly elliptic-linear, oblong-lanceolate, sometimes ovate to obovate, 29–85 mm long, 4–25(–38) mm wide, the margins sometimes crisped,apex acuminate to acute, sometimes falcate.
Filaments filiform, sometimes flattened, 10–45 mm long; anthers straight to curved, 5.5–15 mm long.
Ovary 4–13 mm long, 1–5 mm wide; style 9–50 mm long.
Capsule 37–50 mm long, 10–14 mm in diameter; seeds 4 mm.
Leaves alternate, sometimes opposite or verticillate and clustered, sometimes clustered above the middle of the stem, sessile, base sometimes sheathing the stem, ranging from linear, elliptic-lanceolate, elliptic to ovate, 6–17.5 cm long, 0.4–5 cm wide, apex acute, acuminate, falcate or ending in a tendril.
Herb, stem erect, simple or branched, sometimes not higher than 40 cm, or plant scandent or climbing, up to several meters long.
A climbing plant. Stems terete, glabrous. Leaves about 10 cm long, 4-8 cm broad, ovate, long-acuminate into a tendril, glabrous. Flowers solitary; buds ovate in outline, winged. Pedicel up to 13 cm long, terete, glabrous, sharply bent at the apex. Perianth-segments at first a pale yellow in colour, changing to red above and yellow beneath when more mature, at first horizontal and then strongly reflexed, 5 cm long, 2 cm broad, lanceolate, acuminate, with a deeply channelled claw, keeled in the channel. Stamens at first pointing downwards, at length becoming horizontal and radiating, 2-7 cm long; anthers 1-2 cm long, 3 mm broad, linear. Ovary 1-7 cm long, deeply 3-lobed; style bent at right angles to the ovary, 3-8 cm long; lobes 3 mm long.