Banksea speciosa J. König in Retzius, Observ. Bot. 3: 75. 1783; Costus formosanus Nakai.
Stems 1--3 m, base slightly woody, apex branched and spirally twisted when old. Petiole 5--7 mm; leaf blade oblong or lanceolate, 15--20 × 6--10 cm, abaxially densely sericeous, base subrounded, apex acuminate or caudate-acuminate. Inflorescences terminal, ellipsoid or ovoid, 5--15 cm; bracts bright red, ovate, ca. 2 cm, leathery, pubescent, apex sharply pointed; bracteoles pale red, 1.2--1.5 cm. Calyx red, 1.8--2 cm, leathery, apex 3-lobed; lobes reddish black, rigid, and densely sericeous at apex. Corolla tube ca. 1 cm; lobes oblong-elliptic, ca. 5 cm, apex white or red. Labellum white, trumpet-shaped, 6.5--9 cm, apex toothed and crisped, with edges overlapping. Stamen petaloid, white with orange-yellow base, urceolate, ca. 4.5 × 1.3 cm, pubescent. Capsule red, globose, ca. 1.5 cm, slightly woody. Seeds black, glossy, ca. 3 mm. Fl. Jul--Sep, fr. Sep--Nov. 2 n = 18, 27*, 36.
Forest margins, moist places in valleys, roadsides; near sea level to 1700 m. Guangdong, Guangxi, Taiwan, Yunnan [Bhutan, Cambodia, India, Indonesia, Laos, Malaysia, Myanmar, Nepal, Philippines, Sri Lanka, Thailand, Vietnam; Australia].
Medicinal.
