Spreading to erect shrubs and small trees; young stems and inflorescences viscid or not, glabrous to tomentose. Leaves alternate, subsessile or petiolate; lamina not recurved to strongly revolute, sometimes mucronate. Inflorescences corymbose, pyramidal or of compact clusters. Capitula cylindric, turbinate or campanulate, white, cream, yellow or pinkish; involucral bracts in several series, boat-shaped, usually erect; receptacle bract(s) present or absent; female florets absent; bisexual florets tubular, 5-lobed, anthers tailed at base; style branches truncate, papillose. Cypselas glabrous or glandular-papillose, with or without persistent pappus.
Hybrids occur between sympatric species of this genus, and also with species of Ozothamnus (e.g Cassinia laevis × Ozothamnus ferrugineus, and Cassinia aculeata × Ozothamnus obcordatus). Several species (particularly C. longifolia, C. trinerva, C. uncata) are known to cause allergic reactions (skin irritation, and in extreme cases bronchial constriction) by release of a reactive protein in the resinous exudate.