Perennial herbs. Inflorescence of paniculate cymes; flowers 5-merous. Calyx-tube (fig. 9/1) ovoid or urceolate, with ± dense simple spinulose hairs only or intermixed with caducous clawed scale-like appendages with compound stellate-setose hairs; lobes caducous; intersepalar appendages absent. Stamens 10, markedly unequal (subequal in “ osbeckioid ” forms); 5 large stamens with long connectives, each with a thick bilobed anterior appendage; 5 small stamens with short connectives and a bilobed anterior appendage. Ovary 5-locular, adhering to the calyx-tube by 5 septa, apex with long simple setose hairs; fruiting calyx developing a long neck with distinct longitudinal ribs. Seeds ± 0.5 mm. in diameter.