SIAM WEED

Chromolaena odorata

PROHIBITED MATTER – REPORT THIS WEED (02) 6623 3800

PREVENT THIS WEED

Description A shrub around 2 m tall, but up to 20 m if supported but other trees and shrubs.

Leaves Alternate, diamond or arrowhead-shaped, 5–12 cm long and 3–7 cm wide, lobed or shallow toothed on the margins, with 3 prominent veins. Pungent smelling when crushed.

Flowers Pale blue-lilac or pink mauve, 8–10 mm long and 3–4 mm wide, topped with soft threads on short stalks. Flowers from May to October.

Stems Yellowish, finely ribbed, slightly hairy and branching in opposite pairs along the main stems. Soft when young, then hard and woody when mature.

Dispersal Seed dispersed by wind or attached to clothing, machinery, equipment and animals.

Confused with Weed species Praxelis (Praxelis clematidea), Billygoat weed (Ageratum houstonianum, A. conyzoides), Crofton weed (Ageratina adenophora). Native species Indian weed (Sigesbeckia orientalis)

Control Please do not attempt to treat or dispose of this weed yourself. Call (02) 6623 3800 if you see this plant anywhere in the Far North Coast region.

CONTAINS PYRROLIZIDINE ALKALOIDS WHICH ARE TOXIC TO LIVESTOCK AND HIGHLY POISONOUS TO CATTLE AND CAN CAUSE CATTLE DEATHS.