Madia Molina
Annual or occasionally perennial herbs. Lvs opposite at least below, often alternate above, simple, usually entire, sometimes denticulate at base. Capitula subsessile or pedunculate, in loose to congested corymbs or racemes. Involucral bracts in 1 row, foliaceous. Receptacle flat or convex, with a single ring of scales between ray and disc florets and these often united, otherwise glabrous or hairy. Outer florets ♀, ligulate, usually yellow. Inner florets ⚥ or functionally ♂, tubular. Achenes all similar, usually laterally compressed, narrowed to base, ± 3-angled and sometimes ribbed; pappus usually 0, sometimes a small corona or of scales.
Key
1
Flowering and fruiting capitula in loose corymbs or racemes, only clustered in bud; lvs not exceeding capitula in uppermost part of infl.
Flowering and fruiting capitula congested in terminal and lateral glomerules; lvs clearly exceeding capitula in uppermost part of infl.
c. 18 spp., western N. America, S. America. Naturalised spp. 2.
