Description from Flora of China
Mussaenda inflata H. S. Hsue & H. Wu.
Climbing shrubs; branches terete, densely ferruginous- or gray villosulous, hirtellous, or tomentulose. Leaves opposite; petiole (2-)3-15 mm, moderately to densely villosulous, tomentulose, or velutinous; blade drying papery to subleathery, abaxially pale, oblong-elliptic, lanceolate, or ovate, (4-)7-13 × (2-)2.5-4 cm, adaxially sparsely to moderately hirtellous or hispid with pubescence usually denser along principal veins, abaxially moderately to densely villosulous, hirtellous, or strigose-hirsute, base acute, cuneate, or rounded, apex acute or acuminate; secondary veins 5-8 pairs, tertiary venation visible and reticulate; stipules persistent (or in M. inflata form deciduous), triangular, (4-)5-10 mm, densely strigose, villosulous, or pilose, deeply 2-lobed, lobes lanceolate, narrowly triangular, or linear. Inflorescence subcapitate to congested-cymose, (1-)1.5-4 × 1.5-4 cm, densely villosulous to hirsute, pedunculate; peduncle 0.3-1.5 cm; bracts linear-lanceolate, 4-6 mm. Flowers subsessile or sessile, biology not noted. Calyx sparsely to densely villosulous or villous; hypanthium portion ellipsoid to subglobose, 1.5-2 mm; lobes linear to narrowly triangular, (4-)7-10(-13) mm, sometimes 1 lobe on 1-3 flowers per inflorescence expanded into calycophyll, blade broadly elliptic to ovate, (2.5-)4-6 × (2-)3-5 cm, sparsely strigillose to villosulous with pubescence usually denser on veins, base cuneate to rounded, stipe 10-14 mm, apex rounded or acute. Corolla yellow to orange-yellow, salverform, outside densely strigose to sericeous; tube cylindrical and 26-28 mm (or constricted in throat and 18-19 mm in M. inflata form); lobes elliptic to lanceolate, 4-6 mm, adaxially densely yellow papillose, acute to acuminate. Berry ellipsoid or subglobose, 14-20 × 9-12 mm, lenticellate, with calyx limb persistent, with pedicels sometimes elongating, to 4 mm. Fl. Apr-Jun (Nov in M. inflata form), fr. Jul-Jan of following year.
The name Mussaenda inflata was based on a single specimen distinguished primarily by a notably swollen corolla. Deng and Zhang (Acta Phytotax. Sin. 44: 608-609. 2006) studied this and concluded that M. inflata is a synonym of M. hirsutula and was described based on a specimen with malformed corollas. In the description above, in general, the measurements in parentheses apply only to the plants previously included in M. inflata.
● Thickets in fields, at streamsides, or in valleys, often on tree crowns; 300-800 m. Guangdong, Guizhou, Hainan, Hunan, Yunnan.