Annual or perennial rosetted or subshrubby herbs; indumentum of simple eglandular and/or glandular hairs, or plants glabrous. Leaves alternate, usually toothed to some degree. Capitula terminal, pedunculate, solitary or in corymbose or paniculate inflorescences, radiate or discoid; involucral bracts in 2–4 rows, herbaceous. Ray florets female, in 1–2 rows, white to blue or purple, style branches smooth to papillose; disc florets bisexual, corolla 5(–4)-lobed, yellow, anthers obtuse at base, with a short, acute, membranous terminal appendage, style branches with small conical protuberances. Cypselas uniform, flattened, glabrous or pubescent, marginal ribs thickened (at least in Australian species); pappus bristles free, barbellate, in a single series.
Cosmopolitan genus of c. 200 species, most native to North America; c. 12 (7 introduced) in Australia.
Most non-native members of this genus in Victoria were formerly treated as Conyza but molecular studies have shown that it, and several other (non-Australian) genera are nested within Erigeron (e.g. Noyes 2000). Until a satisfactory treatment of the group has been accepted, a broad but monophyletic Erigeron is employed here. The correct placement of the native Erigeron conyzoides remains uncertain but morphological features suggest that it belongs with 'Conyza-like' species and it is here retained within Erigeron. Other Victorian species previously included in Erigeron have been transferred to Pappochroma Raf. (q.v.).
Noyes, R.D. (2000). Biogeographical and evolutionary insights on Erigeron and allies (Asteraceae) from ITS sequence data., Plant Systematics and Evolution 220: 93–114.