Blackstonia
Annual glabrous herbs. Leaves sessile, sometimes rosetted at base, more or less connate at their bases. Inflorescence few-flowered, a dichasium or monochasium, or a single flower. Perianth 6–12-partite; calyx deeply lobed, lobes narrow; corolla-lobes spreading, much longer than tube; stamens shortly adnate to corolla-tube, anthers not twisting after dehiscence; ovary ellipsoid, 1-locular, style bifid near apex, stigmas 2, bifid. Capsule septicidal, splitting to base, remaining enclosed in persistent calyx and corolla; seeds numerous, small, reticulate or alveolate.
5 or 6 species, from Europe and the Mediterranean region; 1 species naturalised in Australia.
Walsh, N.G. (1999). Gentianaceae. In: Walsh, N.G.; Entwisle, T.J., Flora of Victoria Vol. 4, Cornaceae to Asteraceae, pp. 310–321. Inkata Press, Melbourne.