40. Hedyotis merguensis Bentham & J. D. Hooker, Gen. Pl. 2: 57. 1873.
合叶耳草 he ye er cao
Hedyotis connata J. D. Hooker, nom. illeg. superfl.; H. coronaria (Kurz) Craib; H. coronata Wallich ex J. D. Hooker & B. D. Jackson, nom. illeg. superfl.; Oldenlandia connata K. Schumann, nom. illeg. superfl.; O. coronata F. N. Williams, nom. illeg. superfl.; Scleromitrion coronarium Kurz.
Herbs, perennial or perhaps annual, procumbent; stems to 30 cm, weakly 4-angled to terete, sometimes sulcate, densely pilosulous or hispidulous just below nodes grading to glabrous at bases of internodes. Leaves sessile or subsessile; blade drying membranous or thinly papery, oblong-elliptic or oblong-lanceolate, 2.5-10 × 1-3 cm, glabrous except sometimes puberulent along midrib abaxially and/or scaberulous along margins, base obtuse to rounded, apex obtuse to acute; secondary veins 3-5 pairs; stipules fused to petiole bases, triangular to rounded, 3-4.5 mm, puberulent to glabrescent, ciliolate, with 5-7 linear lobes or bristles 2-12 mm. Inflorescences terminal and/or pseudoaxillary on short lateral stems, capitate, 1-1.5 cm in diam., several flowered, sessile, enclosed by stipules and leaf bases, subtended by 2 or usually 4 leaves; bracts not seen. Flowers sessile or subsessile, apparently distylous. Calyx glabrous; hypanthium portion ellipsoid, ca. 2 mm; limb deeply lobed; lobes lanceolate, oblanceolate, or spatulate, 4-5 mm, distinctly veined, ciliolate. Corolla white tinged with pink or lilac, funnelform, outside glabrous; tube 9-12 mm, pubescent in throat; lobes lanceolate to triangular, ca. 3 mm. Anthers 1-1.5 mm, exserted or included. Stigma 1-1.5 mm, exserted or included. Fruit indehiscent, ellipsoid to obovoid, 2.2-3 mm, papery, glabrous, with calyx lobes to 5.2 mm; seeds numerous, black, angled or ridged. Fl. [Aug-Oct in Thailand].
Bamboo forests, on rocks at streamsides; 600-1000 m. Hainan, Yunnan (Mengla) [India, Malaysia, Myanmar, Philippines, Thailand, Vietnam].
The widely used name Hedyotis coronaria was synonymized with H. merguensis by Bakhuizen f. (Fl. Java 2: 286. 1965); this synonymy was accepted by Dutta and Deb (Taxon. Rev. Hedyotis. 2004) but overlooked by some other authors.