Greek pyknos — dense, soros — heap, a reference to the dense florets in compound heads.
Annual or perennial herbs, variously hairy. Stems 1 or few, erect, unbranched. Leaves basal and/or along stems, alternate, margins entire, basal leaves withering early. Capitula diskoid, few-flowered, usually 40-200 grouped together in dense terminal compound heads, sometimes surrounded by a common involucre. Involucral bracts few, overlapping, membranous, yellow. Common receptacle with scales, spherical to conical. Florets bisexual, tubular, yellow. Achenes obovoid, silky. Pappus a ring of feathery bristles variously fused at base and yellow at tip.
Yellow spherical compound heads.
6 species from Australia.
Everett & Doust (1992).
Source: (2002). Dahlia. In: . Horticultural Flora of South-eastern Australia. Volume 4. Flowering plants. Dicotyledons. Part 3. The identification of garden and cultivated plants. University of New South Wales Press.