Ageratina Spach

From Ageratum, the name of a related genus often used in horticulture.

Perennial herbs, shrubs or small trees, often glandular-hairy. Stems erect or ascending, branched. Leaves along stems, opposite, rarely alternate, simple, margins toothed, petiolate. Capitula diskoid, terminal, in dense panicles, with stalks. Involucral bracts in 1 or 2 rows, slightly overlapping, equal. Receptacle flat or convex. Florets bisexual, tubular, white, pink or pale mauve. Achenes 5-angled, hairy or glandular. Pappus of many barbed or feathery bristles, deciduous.

Three species have become naturalised in Australia and are declared noxious weeds.

Weakly 5-angled achenes; glandular-hairy herbs or subshrubs; leaves simple, toothed.

About 290 species from N, S and C America.

Source: Jeanes, J. (2002). Asteraceae. In: Spencer, R.. Horticultural Flora of South-eastern Australia. Volume 4. Flowering plants. Dicotyledons. Part 3. The identification of garden and cultivated plants. University of New South Wales Press.

kingdom Plantae
phylum   Tracheophyta
class    Magnoliopsida
superorder     Asteranae
order      Asterales
family       Asteraceae
Higher taxa
Subordinate taxa