Volume 15 > Part 1 > Year 2021 > Page 189 > Rubiaceae > Argostemma

31. Argostemma verticillatum Wall.wfo-0000267155

in Roxb., Fl. Ind. 2: 325. 1824; Benn., Pl. Jav. Rar. 1: 94. 1838; Hook.f., Fl. Brit. India 3: 43. 1880; Pit. in Lecomte, Fl. Indo-Chine 3: 80. 1922; Craib, Fl. Siam. 2: 35. 1932; Kanjilal, Fl. Assam 3: 36. 1939; Sridith, Thai Forest Bull., Bot. 27: 118, fig. 20. 1999.

Accepted Name : This is currently accepted.

Synonyms & Citations :

Description : Perennial herbs, attached to substrate with dense, much-branched matted roots; stems erect, 3.5–7 cm long, glabrous. Stipules oblong or ovate, ca 0.5 by 0.5 mm, tip bifid or entire, entirely glabrous, or sometimes reduced to minute filiform appendages. Leaves opposite, in 2 pairs, internodes between leaf pairs very short, pseudo-verticillate, slightly anisophyllous; blades elliptic or ovate, (1.2–)1.8–7.5 by (0.4–)0.8–2.3 cm, acute at base, acute or acuminate at apex, membranaceous, midrib with several pairs of ascending lateral veins, both conspicuous and raised on both surfaces, discolorous (pale or light green beneath, darker above), sparsely pubescent above, glabrous beneath; petiole subobsolete. Inflorescences 3–12-flowered, compound cymes; peduncles 0.7–1 cm long, glabrous; bracts in groups of 4, free or basally fused, elliptic, oblong or linear, 1.5–2(–8) by 0.5–1(–1.5) mm, green, glabrous; pedicels 3–5 mm long, glabrous. Flowers 5-merous zygomorphic. Calyx coriaceous or chartaceous, green; lobes triangular, ca 1 by 0.5–1.5 mm, spreading, glabrous, raphides very conspicuous. Corolla white, star-shaped, glabrous; tube very short, ca 0.5 by 1 mm; lobes triangular, 3.5–4 by 1.5 mm, spreading, sometimes tips recurved, raphides very conspicuous. Stamens 5; filaments curved, fused around middle and forming a short filament tube, 1.5–2 mm long; anthers yellow, free but in a cone-like arrangement, basifixed, oblong, ca 2 mm long, with very short apical appendages, opening by oblique elongated pores. Ovary ca 1 mm, glabrous; style filiform, 2–2.5 mm long, as long as anthers or barely longer (less than 0.5 mm), glabrous; stigma capitate. Fruits globose, ca 2 mm in diam., glabrous.

Thailand : NORTHERN: Chiang Mai, Lampang.

Distribution : India (type), Nepal, Myanmar, China (Yunnan), N Vietnam.

Ecology : On moist rocks along streams in lower and upper montane forests, 700–2,200 m alt. Flowering: July–August; fruiting: August.

Vernacular : Dao noi (ดาวน้อย)(Chiang Mai); dao wao (ดาววาว)(Nakhon Si Thammarat).