Little ironweed

Cyanthillium cinereum is an erect annual or short-lived perennial herb of the Asteraceae family growing 30-100 cm tall from a slender taproot. Stems are slender, longitudinally ridged, branched in the upper part and clothed with a fine appressed grey pubescence (whence the epithet cinereum). Leaves are alternate, lanceolate to obovate-elliptic, 2-8 cm long with shallowly serrate to crenate margins, an acute to obtuse apex and a cuneate base often decurrent into a short petiole; the upper surface is dull green and sparsely hairy while the lower is conspicuously pale and silvery-grey from a dense covering of short hairs. The inflorescence is a loose, much-branched, flat-topped corymb of numerous small heads borne on slender pedicels. Each head is 4-7 mm long, cylindrical to narrowly campanulate, with two to three rows of acute appressed bracts and contains 15-25 small pinkish-purple to lilac tubular florets, all bisexual and slightly exserted. The achene is small, narrowly oblong, hairy and crowned with a double pappus of long persistent white silky bristles. Native to tropical Asia and Africa and now widely naturalised throughout the global tropics and subtropics, common on roadsides, fallow fields and disturbed open ground.