Greek peri — around, kallos — beauty, an apparent allusion to the often colourful ray florets.
Perennial herbs or shrubs, mostly hairy. Stems procumbent to erect. Leaves basal and/or along stems, alternate, margins toothed to lobed, petiolate. Capitula radiate, terminal, in corymbs or rarely solitary, with stalks. Involucral bracts in 1 row, many, equal. Receptacle flat. Ray florets female, ligulate, white, pink, violet, purple or bluish. Disk florets bisexual, tubular, yellow. Achenes oblong to obovate, somewhat compressed, ribbed, hairy. Pappus of fine bristles, sometimes absent in ray achenes.
Often large capitula with colourful ray florets; palmately veined leaves.
About 15 species from Macaronesia.
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.