Description from Flora of China
Shrubs, deciduous, 1.5-4 m tall; branches angled to subterete, often becoming red, hirtellous or pilosulous to glabrescent. Leaves 2, 3, or 4(or 5) per node; petiole 1.5-4.5 cm, pilosulous or hirtellous to glabrous; blade drying papery to membranous, elliptic to oblanceolate, 7-20 × 4-6 cm, both surfaces pilosulous or hirtellous to glabrescent, base cuneate to acute, apex acute to weakly acuminate; secondary veins 7-9 pairs, in abaxial axils frequently with pilosulous domatia; stipules narrowly triangular to subulate, 2-6 mm, hirtellous or pilosulous to glabrescent. Inflorescences corymbiform, villosulous or pilosulous to glabrescent; peduncle 1-8 cm; branched portion corymbiform, 1.5-7 × 1.5-9 cm; bracts reduced or triangular, 0.2-0.5 mm. Flowers subsessile to pedicellate; pedicels to 2 mm. Calyx hirtellous to glabrous; ovary portion ellipsoid, ca. 3 mm; limb deeply lobed; lobes triangular, 0.8-1 mm. Corolla red to red-orange or yellow, narrowly tubular, outside puberulent to glabrous; tube smooth to shallowly 5-ribbed, 16-23 mm; lobes ovate-triangular, 1-2 mm, acute. Berry ovoid, 6-7 mm in diam., puberulent to glabrescent. Fl. May-Dec.
In S China and in cultivation in general this species does not set fruit; the fruit description here is based on wild plants. The flowers of the cultivated plants range from yellow to dark scarlet red, and in recent years many new cultivars have been developed.
Cultivated in gardens in Fujian, Yunnan [native and weedy in Mexico, United States (Florida), and the Caribbean region, Central America, and tropical South America; cultivated as a perennial in tropical regions and an annual or indoors in temperate regions worldwide].