Ageratina riparia (Regel) R.M.King & H.Rob.
mist flower
Erect or sprawling perennial herb to subshrub, 0.3-1-(2) m tall. Stems moderately to densely clothed in purple-striped eglandular hairs at least above, often tinged purple, much-branched. Lvs opposite; petiole hairy, 12-20 mm long; lamina glabrescent to sparsely hairy especially on veins of lower surface, narrow-elliptic to lanceolate, acuminate, coarsely serrate except near base, (30)-60-100-(130) × (8)-15-25-(40) mm; uppermost lvs smaller, sometimes entire. Capitula 4-5 mm diam., many in terminal corymbs; peduncle clothed in eglandular hairs. Involucral bracts in 2 ± equal rows, usually with shorter, narrower supplementary bracts outside, narrow-elliptic to lanceolate, hairy, 4-5 mm long. Florets white. Achenes black, 5-angled, hairy especially on angles, 1.5-2 mm long.
N.: common in N. Auckland, local in S. Auckland, Lower Hutt, Wellington City.
Mexico, W. Indies 1931
Forest margins and clearings, waste places, damp banks and streamsides.
FL Aug-Jan-(Mar).
Poisonous (Connor 1977).
Mist flower is easily distinguished from A. adenophora in the vegetative state by the multicellular purple-striped eglandular hairs of the upper stem and petioles. It has previously been known in N.Z. as Eupatorium riparium.