Volume 15 > Part 1 > Year 2021 > Page 129 > Rubiaceae > Scleromitrion

3. Scleromitrion diffusum (Willd.) R.J.Wangwfo-0001341321

J. Trop. Subtrop. Bot. 22: 440. 2014.— Hedyotis diffusa Willd., Sp. Pl. 1: 566. 1798; Fukuoka, S.E. Asian Stud. 8(3): 333. 1970; Tao Chen & C.M.Taylor in Z.Y.Wu et al., Fl. China 19: 161. 2011; R.J.Wang in K.M.Wong et al., Fl. Singapore 13: 109, fig. 30. 2019, p.p. excl. Scleromitrion brachypodum.— Oldenlandia diffusa (Willd.) Roxb., Hort. Beng.: 11. 1814; Fl. Ind. 1: 444. 1820; Miq. Fl. Ned. Ind. 2: 188. 1857; Ridl., Fl. Malay Penins. 2: 54. 1923.

Accepted Name : This is currently accepted.

Description : Annual herbs 10–40 cm tall or long, erect, ascending or procumbent; stems terete, not ribbed, scabrid throughout. Stipules sheath membranous, truncate to triangular, lobes as 3–7 filiform appendages, tip with colleter. Leaves narrowly elliptic, narrowly oblong or linear, 10–40 by 0.5–3 mm, apex acute, base acute, scabrid near margin above, midrib scabrid beneath; petiole absent or short. Inflorescences axillary, umbellate, with 2–4 flowers, or flowers solitary; peduncles 1–3 per axil, 4–15 mm long. Flowers white, tubular; homostylous; pedicels 0.4–1.2 cm long, slender, scabrid throughout. Calyx lobes ovate to oblong, 0.4–0.7 by ca 0.3 mm, margin muricate. Corolla tube 1–1.2 mm long, lobes ovate-deltoid, 0.5–1 by 0.3–0.4 mm, outside and inside glabrous. Stamens slightly exserted from corolla, adnate at corolla lobe sinuses; filaments ca 0.2 mm long, glabrous; anthers ovate, 0.2–0.3 by ca 0.2 mm. Ovary glabrous or subscabrous; style 1.3–1.5 mm long, glabrous; stigma exserted, short, rounded. Capsules oblate, 1.5–2.5 by 2–3 mm, widest at middle, top of capsule protruding not over calyx apex. Seeds 35–60 per locule, angular, 0.2–0.3 by 0.2–0.3 mm, reticulate.

Thailand : NORTHERN: Chiang Mai (Doi Mae Salong, Ban San Pa Sak), Chiang Rai (Ban Wiang Song, Thoeng, Mae Sai); NORTH-EASTERN: Kalasin (Yang Tlat); EASTERN: Si Saket (Hua Kua, Tham Yae, Phayu), Ubon Ratchathani (Ban Kut Riang Mun, Nam Yuen); CENTRAL: Ang Thong (Wat Klang), Krung Thep Maha Nakhon (Bangkok); PENINSULAR: Phangnga (Ko Talibong).

Distribution : Tropical and subtropical Asia from India, Nepal to the Philippines and China (type from India Orientalis).

Ecology : Open places, rice fields, swampy areas, 250–1,100 m alt. Flowering throughout the year.

Vernacular : Ya lin ngu yai (หญ้าลิ้นงูใหญ่).