Leaves alternate, basal and cauline, entire or toothed.
Inflorescence of pedunculate heads in large terminal corymbs or panicles; heads hemispherical to campanulate becoming reflexed; involucral bracts linear to lanceolate, herbaceous with scarious margins, imbricate; receptacle naked, pitted, flat. Outer florets female, filiform or ligulate; ligules very short, white to pink or absent. Disc florets bisexual, few or many, tubular, usually yellow. Anthers obtuse at base. Style branches with terminal appendages.
Achenes flattened, with marginal ridges, glabrous or pubescent. Pappus of numerous capillary bristles.
| ||Key to the species|| |
|1||Involucral bracts glabrous or almost so; heads usually 3–4 mm long||2|
|Involucral bracts hairy; heads usually 4–12 mm long||4|
|2||Involucre cylindrical; involucral bracts narrow-oblong; outer florets with short but prominent white ligules||3|
|Involucre subglobular; involucral bracts narrow-triangular; outer florets filiform with an inconspicuous oblique limb|
Back to 1
|3||Stems very hairy; leaf margins ciliate, involucral bracts with a few hairs and without purplish spot at apex||Conyza canadensis|
|3||Stems not noticeably hairy; leaf margins with a few scattered cilia only at base; involucral bracts glabrous, usually with purplish spot||Conyza parva|
|4||Heads 8–12 mm long||Conyza primulifolia|
|4||Heads < 8 mm long, usually 4–6 mm long||5|
|5||Hairs on stems and involucral bracts rusty; hairs on leaves on both surfaces, minute, yellow, and glandular||Conyza leucantha|
|Hairs on stems hirsute with septate hairs; involucral bracts hirsute; leaves hispid with short antrorse hairs or leaves hispid with short antrorse hairs and long septate hairs present|
Back to 4
|6||Involucral bracts at least with a few long hairs at apex and when reflexed at maturity whitish on the inside; pappus white or pinkish; receptacle smooth pitted||Conyza bonariensis|
|Involucral bracts without long hairs at apex; pappus straw or golden; receptacle usually rough pitted|
Back to 5