NOVON 7(3): 252. 1997.

Pollia macrobracteata Hong, a New Species of Commelinaceae from China

Hong De-yuan

Laboratory of Systematic and Evolutionary Botany, Institute of Botany, Chinese Academy of Sciences, 20 Nanxincun, Xiangshan, Beijing 100093, China

ABSTRACT. Pollia macrobracteata, a new species from Guangxi (China), is described, and its relationship and distinguishing characters are discussed.

During my 1994 visit to the Missouri Botanical Garden to study Chinese plants of various families, the following new species was discovered. The species is herein described to make the name available for the forthcoming volume 24 of the Flora of China.

Pollia macrobracteata Hong, sp. nov. TYPE: China. Guangxi: Longzhou, Daqing Shan, jungle at mountain summit, 30 May 1935, S. P. Ko 55196 (holotype, IBSC; isotype, MO).

Polliae japonicae Thunberg et P. hasskarlii R. S. Rao affinis, sed ab eis foliis multo minoribus atque vaginis foliaribus brevioribus differt; ab illa pedunculis inflorescentiisque multo brevioribus atque bracteis ovatis majoribus apice late acutis differt; a hac bracteis herbaceis majoribus, cincinnorum pedunculis pedicellisque longioribus atque radicibus caulinis multo gracilioribus differt.

Herbs perennial, more than 35 cm tall. Stems ascending, unbranched; lower part ca. 5 mm diam. when dry, glabrous, lower node with roots ca. 0.5 mm diam.; internodes 4--4.5 cm long. Sheaths ca. 6 mm long, sparsely puberulent on the side opposite the leaf blade, glabrous elsewhere; lamina sessile, elliptic, 7--12.5 cm long, ca. 3 cm wide, glabrous on both surfaces, apex cuspidate; uppermost leaves smaller, lanceolate, ca. 3 cm long, ca. 0.9 cm wide, apex acuminate. Inflorescences (excluding peduncle) 8--12 cm long, ca. 4 cm wide, hooked hairy on axes; peduncle ca. 4.9 cm long; cincinnus bracts herbaceous, ovate, ca. 13 cm long, ca. 7.5 mm wide, apex broadly acute, upper ones slightly smaller; cincinni whorled or nearly so, whorls 6, each with 2--4 cincinni; cincinni 3- or 4(or more)-flowered, with peduncles 7--9 mm long; bracteoles membranous, glabrous, ca. 2 mm long, very wide and almost entirely clasping cincinnus axes; pedicel ca. 4 mm. Flowers actinomorphic; sepals 3, ca. 6 mm long, free, hooded, sparsely hooked hairy outside; petals white, purple spotted, narrowly oblong, ca. 6 mm long, ca. 3 mm wide; stamens 6, all fertile, equal; filaments glabrous, ca. 4 mm long; anthers narrowly oblong, locules parallel. Style glabrous, ca. 4.5 mm long; stigma capitate. Fruit not seen.

Pollia macrobracteata is related to P. japonica and P. hasskarlii: all three have six fertile stamens and relatively dense inflorescences. However, P. macrobracteata is easily distinguished from these by its much smaller leaves and shorter sheaths. From P. japonica, it differs in having peduncles ca. 4.9 cm long, inflorescences ca. 12 cm long, sparsely hairy sepals, and cincinnus bracts that are ovate, larger, and broadly acute. In P. japonica, the peduncles and inflorescences are much longer, the sepals are glabrous, and the cincinnus bracts are lanceolate and apically acuminate. From P. hasskarlii, P. macrobracteata is readily distinguished by having larger, herbaceous (instead of membranous) cincinnus bracts, longer cincinnus peduncles and pedicels, and more slender (0.5 vs. 3 mm) roots from the lower stem nodes. Both P. hasskarlii and P. macrobracteata have undulate petiole/lamina bases, shorter peduncles, large cincinnus bracts, and pubescent sepals.