e-Flora of Thailand
Volume 15 > Part 1 > Year 2021 > Page 128 > Rubiaceae > Scleromitrion
1. Scleromitrion angustifolium (Cham. & Schltdl.) Benth.wfo-0000307444
Hooker’s J. Bot. Kew Gard. Misc. 4: 172. 1852; R.J.Wang, Phytotaxa 414: 121, fig. 1 B–E. 2019.— Hedyotis angustifolia Cham. & Schltdl., Linnaea 4: 153. 1829; Kurz, J. Asiat. Soc. Bengal, Pt. 2, Nat. Hist. 46(2): 134. 1877; Ratna Dutta & Deb, Taxon. Revis. Hedyotis L. (Rubiac.) Indian Subcont.: 166. 2004; R.J.Wang in K.M.Wong et al., Fl. Singapore 13: 113. 2019.
Accepted Name : This is currently accepted.
Synonyms & Citations :
Description : Annual or perennial herbs 10–50 cm tall, procumbent or prostrate, rooting at nodes; stems terete or quadrangular 4-ribbed, grooved, glabrescent. Stipules sheath triangular, hispid, lobes as 5–7 bristles, longer than sheath, with 3–7 colleters. Leaves narrowly linear to elliptic or narrowly oblong, 1–4.5 cm by 1–5 mm, subcoriaceous, apex acute to acuminate, base cuneate or attenuate, margins revolute, scabrous near margin above, scabrous on veins or glabrous beneath, lateral veins indistinct beneath; petiole absent to 2 mm long. Inflorescences axillary, capitate, with 1–9 flowers per node. Flowers white or creamy white, infundibular; homostylous; stamens and style exserted; pedicels absent or to 1 mm long. Calyx tube 0.4–0.6 mm long; lobes narrowly deltoid, 1–1.5 by 0.3–0.7 mm, erect, margin hirsute-fimbriate. Corolla tube 1–1.5 mm long; lobes oblong, 1.5–2 by 0.7–1 mm, apex acute, glabrous on both surfaces. Filament 1.3–1.5 mm long, glabrous; anthers white, oblong, 1–1.3 by 0.4–0.5 mm. Ovary glabrous; style 2.5–3.5 mm long, glabrous; stigma 0.2–0.3 mm long. Capsules ovoid, 2.5–3.5 by 2–3 mm, widest at middle of capsule or nearly so, persistent calyx erect, convergent. Seeds 30–60 per locule, 0.2–0.3 by 0.2–0.3 mm.
Thailand : NORTHERN: Mae Hong Son (Khun Yuam), Chiang Rai (Doi Tung), Nan (Doi Phu Kha, Saphun Falls); NORTH-EASTERN: Sakon Nakhon (Phu Phan); EASTERN: Chaiyaphum (Thung Kramang); PENINSULAR: Chumphon (Thung Tako).
Distribution : India, Sri Lanka, Myanmar, China, Malaysia, the Philippines (type).
Ecology : In moist open areas of evergreen forests or rarely in shaded areas, 0–1,500 m alt. Flowering: May–December.
Vernacular : Tong haeng hin bai man (ตองแห้งหินใบมัน).
Notes: Dutta & Deb (2004) separated this species from Scleromitrion tenelliflorum, with which it had often been synonymized before. Moreover, Wang (2019) reported that S. angustifolium is common in China and had been misidentified as Hedyotis tenelliflora, e.g, by Chen & Taylor (2011). Scleromitrion angustifolium is a procumbent or prostrate herb, with leaves scabrous near margins above, the flowers clustered or solitary in leaf axils, and glabrous capsules.