Diminutive of Latin pilosus — hairy, as most species are abundantly hairy.
Perennial herbs, stoloniferous, hairy. Stems few to many, scape-like, erect. Leaves mostly basal, margins entire to toothed. Capitula radiate, terminal, solitary or a few together, with stalks. Involucral bracts in many rows, overlapping, unequal. Receptacle pitted, flat. Florets bisexual, ligulate, yellow, rarely reddish, greenish or white. Achenes cylindrical to conical, about 10-ribbed, glabrous. Pappus of barbed bristles.
Stoloniferous herbs with mostly basal leaves; florets all ligulate; achenes with toothed ribs.
Depending upon how species are defined, about 20-100 species from Europe, Asia and N Africa.
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.