Erect or diffuse annual or perennial herbs, di- or trichotomously branched Leaves opposite, often small and narrow, sessile or petiolate; stipules mostly acute or acuminate sometimes setaceous, bristly or fimbriate. Inflorescence a dichotomous axillary or terminal panicle or cyme, rarely solitary or fasciculate. Flowers small, generally white or rose, 4-merous, sometimes heterostylous. Calyx-tube subglobose, or turbinate, teeth 4, persistent, mostly distant in fruit. Corolla-tube infundibuliform, rotate or funnel-shaped, throat mostly villose, rarely glabrous, lobes 4, obtuse, valvate. Stamens 4, inserted at the mouth of the corolla-tube, filaments short, anthers dorsifixed, generally exserted rarely included and situated below the stigma (in Flora area); pollen grains globose or ellipsoid, mostly 3-(-4-5) colporate. Ovary 2-loculed, ovules numerous in each locule on peltate placentas; style filiform, glabrous or hirsute; stigmas 2, linear, short and obtuse. Capsule generally membranous, circular, didymous or winged, globose, dehiscence loculicidal at the top or rarely its whole length, many-or sometimes few- seeded; seeds angular or subglobose, testa generally smooth, rarely undulate, minutely punctate, granulate or reticulate.
A genus of c. 100 species, chiefly distributed in warm countries of the old world, represented in Pakistan by 3 species.
Excluded species
Oldenlandia pumila (L.f.) DC., Prodr. 4: 425. 1830; Bremek. in Verh. K. Nederl. Akad. Wet., Afd. Natuurk. Ser. 2, 48 (2): 250. 1952; Verdc. in Polhill, Fl. Trop. East Afr. (Rubiaceae-1) 307. 1976.
Hedyotis pumila L. f., Suppl. Pl. 119. 1781; Oldenlandia crystalline Roxb., Fl. Ind. ed. Carey & Wall. 1: 443. 1820; Hook. f., Fl. Brit. Ind. 3:65.1880; Stewart in Nasir & Ali, Ann. Cat. Vasc. Pl. W. Pak. & Kashmir 688. 1972.
Under the name Oldenlandia crystalline Roxb., Stewart (l.c.) has referred to a specimen collected by T. Thomson from ‘plains below Jammu’. According to him, it is not clear whether the specimen was collected from Jammu or the (Indian) Punjab. In this treatment we have excluded it.
