Scleromitrion tenelliflorum (Blume) Korth., Ned. Kruidk. Arch. 2: 155 1851. (syn: Bigelovia kleinii Wight & Arn.; Bigelovia lasiocarpa Wight & Arn.; Bigelovia mitracarpoides Miq.; Bigelovia myriantha Miq.; Bigelovia roxburghiana Wight & Arn.; Bigelovia striata Span.; Bigelovia stricta (L.f.) Blume; Borreria stricta (L.f.) K.Schum.; Hedyotis angustifolia Cham. & Schltdl.; Hedyotis approximata R.Br. ex Wight & Arn.; Hedyotis kerrii (Craib) Craib; Hedyotis tenelliflora Blume; Oldenlandia angustifolia (Cham. & Schltdl.) Kuntze, nom. illeg.; Oldenlandia tenelliflora (Blume) Kuntze; Oldenlandia tenelliflora var. kerrii Craib; Sclerococcus angustifolius Bartl. ex DC., not validly publ.; Scleromitrion angustifolium (Cham. & Schltdl.) Benth.; Scleromitrion approximatum (R.Br. ex Wight & Arn.) Kurz; Scleromitrion sinense Miq.; Scleromitrion tetraquetrum Miq.; Scleromitrion tetraquetrum var. tenella Miq.; Spermacoce flagellaris Willd. ex Roem. & Schult.; Spermacoce macrophylla Hassk.; Spermacoce muriculata DC.; Spermacoce stricta L.f.; Spermacoce stricta var. latifolia DC.; Spermacoce tubularis R.Br. ex Wall., nom. nud.; Tardavel stricta (L.f.) Hiern); 

Trop. & Subtrop. Asia to N. Queensland as per WCSP;

Assam; Bangladesh; Borneo; China South-Central; China Southeast; East Himalaya;
Hainan; Japan; Jawa; Korea; Malaya; Maluku; Myanmar; Nansei-shoto; New Guinea;
Nicobar Is.; Philippines; Queensland; Sumatera; Taiwan; Thailand; Vietnam
as per Catalogue of Life;


Herbs, annual or perennial, diffusely branched, to 40 cm tall, often drying blackened; stems subterete and smooth or weakly to sharply 4-angled and/or 2-sulcate, glabrous or often scaberulous along grooves and/or near nodes. Leaves sessile or subsessile; petiole to 1 mm, glabrescent; blade drying thinly leathery, linear, linear-lanceolate, narrowly elliptic-oblong, or narrowly spatulate, 1.2-5 × 0.15-0.4 cm, adaxially glabrous or scaberulous near margins, abaxially glabrous, both surfaces sometimes apparently scaly due to collapsed large epidermal cells, base cuneate, acute, or decurrent, margins frequently revolute, apex acute or acuminate; secondary veins not visible; stipules fused to petiole bases, triangular to rounded, 1-2 mm, puberulent, hispidulous, or glabrescent, with 2-5 linear or setiform lobes 1-4 mm. Inflorescences axillary, 1-flowered or 2- or 3-flowered in each axil, congested-cymose, glomerulate, or fasciculate, 4-8 mm in diam., sessile to subsessile; bracts acicular to lanceolate, 1-2.5 mm, entire or marginally scaberulous; pedicels to 1 mm. Flowers sessile to subsessile, apparently homostylous. Calyx glabrous; hypanthium portion subglobose to obovoid, ca. 1 mm; limb lobed nearly to base; lobes linear-lanceolate, triangular, or spatulate, 1.5-2 mm, ciliolate. Corolla white, funnelform, outside glabrous; tube ca. 2 mm, pubescent in throat; lobes narrowly spatulate-oblong, 1-2 mm. Anthers exserted, ca. 1 mm. Stigma 0.2-0.3 mm. Fruit capsular, ovoid, 2-2.5 × 1.5-2 mm, cartilaginous to stiff, loculicidal across top; seeds numerous.

Slopes in valleys, ridges of fields; 100-1400 m.
India, Indonesia, Japan, Malaysia, Philippines, Thailand, Vietnam; Australia, Melanesia
(Attributions- Compiled from secondary sources listed in references by Kishor Deka for the Assam Biodiversity Portal project from India Biodiversity Portal)


References:

Catalogue of Life  Catalogue of Life 2  WCSP  The Plant List Ver.1.1  World Flora Online  Flora of China  FOC illustration  GBIF (high resolution specimens)  Scleromitrion sirayanum (Rubiaceae: Spermacoceae), a new species of the Hedyotis-Oldenlandia complex in Taiwan– Tian-Chuan HSU, and Zhi-Hao CHEN- Taiwania 62(2): 151‒156, 2017- (ABSTRACT: The new species Scleromitrion sirayanum T.C. Hsu & Z.H. Chen (Rubiaceae) is described and illustrated from Taiwan. S. sirayanum is similar to S. angustifolium (Cham. & Schltdl.) Benth. but easily distinguished by its constantly solitary flowers, salverform corolla, adaxially basally long villous corolla lobes, spreading to ascending persistent calyx lobes, and obconic capsules dehiscent both septicidally and loculicidally into 4 valves. S. sirayanum is so far only found in Nanhua District of Tainan City and evaluated as Vulnerable based on the IUCN Red List criteria. Three new combinations are also proposed for the Hedyotis-Oldenlandia complex in Taiwan)