Compilation
Ageratum polyphyllum

Perennial herb 40–125 cm tall, with several annual, sometimes slightly woody, erect stems from a woody rootstock; rootstock with woody taproot; stems tufted, ascending, branching near apex, rather densely leafy, usually densely tomentose and glandular. Leaves alternate, rarely almost whorled, subsessile, overlapping, lanceolate, ovate or elliptic, 1.2–4.5 cm long, 0.4–1.8 cm wide, base cuneate, rounded or cordate into a short petioloid base, obscurely remotely denticulate or subentire, apex acuminate, apiculate, thinly pubescent and glabrescent to finely crispate-tomentose or sericeous-tomentose above, more densely so and silvery or pale grey or rarely almost glabrous except on the main veins beneath, glandular-punctate. Capitula usually numerous in rather dense small scorpioid clusters in moderately dense terminal compound corymbiform cymes; involucre obconic-hemispherical, 3–5 mm long, 2.5–6 mm in diameter at flowering time; phyllaries 3–4-seriate, grey-green, purple near apex, oblong to lanceolate, 1–6.5 mm long, densely tomentose, recurving at the apex. Corolla mauve, lilac or purple (once described as white), densely hairy on lobes and upper part of tube, 4–6.3 mm long, lobes 2–2.5 mm long. Achenes 1.5–2.2 mm long, 4–5-angled, prismatic, glabrous or usually hairy on the angles at least towards the apex, often curved; pappus usually double, outer of 4–8 free or more or less connate shiny scales 0.5–1.3 mm long, inner pappus of fewer slightly longer flattened bristles, or absent. Fig. 53, p. 275.