29. Mussaenda treutleri Stapf, Bot. Mag. 135: t. 8254. 1909.
贡山玉叶金花 gong shan yu ye jin hua
Erect or climbing shrubs; branches terete, moderately to densely villous or hirsute. Leaves opposite; petiole 4-10 mm, hirsute or villous; blade drying membranous to papery, green to brownish, paler below when specimen well preserved, elliptic to ovate, 2.5-21 × 4-11 cm, both surfaces moderately strigillose to pilose on lamina and moderately to densely strigillose to hirsute along principal veins, base cuneate to obtuse, truncate, or rounded, apex acute to acuminate; secondary veins 6-8 pairs, without domatia, tertiary venation reticulate; stipules generally persistent, ovate, 7-12 × 6-12 mm, moderately to densely hirsute or pilose, entire to deeply 2-lobed, segments acute to acuminate. Inflorescences subcapitate to congested-cymose or sometimes with axes later elongating, 2-6 × 2-8 cm, hirsute, sessile to subsessile; bracts lanceolate, 0.5-1 cm, obtuse to acuminate or 2- or 3-parted. Flowers subsessile, biology not noted. Calyx with hypanthium portion campanulate to obconic, 3-4 mm, densely brown strigose to -sericeous; lobes lanceolate, ligulate, or oblanceolate, 7-18 × 3-4 mm, often markedly unequal on an individual flower, densely brown strigillose to -strigose, acute, with 1 lobe on 1 to several flowers on each inflorescence sometimes expanded into white calycophyll, blade ovate or rhombic, 5-7 × 3.5-4 cm, both surfaces sparsely hirsute to glabrescent on lamina and moderately to densely pilosulous to puberulent on principal veins, base obtuse to truncate, stipe 25-37 mm, apex obtuse to shortly acuminate. Corolla orange-yellow, salverform, outside densely spreading villous; tube ca. 22 mm; lobes ovate, 5-7 mm (to 10 mm in other regions), acute to acuminate. Berry ellipsoid, 10-12 × 10-12 mm, strigose, lenticellate, calyx limb deciduous. Fl. Jul-Sep.
Thickets or dense forests on mountains; [600-]1000-1500[-2000] m. Yunnan [Bhutan, NE India, Nepal].
The description of the fruit here is based on specimens from outside our flora region.
This species is similar to Mussaenda macrophylla, and in the protologue M. treutleri was explicitly separated from plants commonly called M. macrophylla, both in the wild and in cultivation; in fact, the protologue noted that M. treutleri was already widely distributed in cultivation at that time incorrectly under the other name. Mussaenda treutleri subsequently has apparently still been confused with or combined with M. macrophylla, including by recent authors (e.g., Springate et al., Fl. Bhutan 2(2): 783. 1999). Mussaenda treutleri is here circumscribed somewhat differently than by H. H. Hsue and H. Wu (in FRPS 71(1): 301. 1999): the plants from montane Yunnan and adjacent regions with broad, generally persistent stipules were separated by Stapf from M. macrophylla and included in M. treutleri, and this distinction is followed here.
The illustration presented for Mussaenda treutleri by Fu et al. (Higher Pl. China 10: 575. 2004) is incorrect; this figure shows a species of Asteraceae.