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Chromolaena odorata

Family

Asteraceae

Botanical Name

Chromolaena odorata (L.) R.M.King & H.Rob.

King, R.M. & Robinson, H.E. (1970) Phytologia 20(3): 204. Type: .

Synonyms

Eupatorium odoratum L., Systema Naturae Edn. 10 2: 1205(1759), Type: ?.

Common name

Siam weed

Weed

*

Stem

Scrambling shrub to 7 m tall, often around 4 m tall. Stem round in cross-section.

Leaves

Simple, entire or toothed, triangular, 4.5-12 x 20-55 mm; upperside hairy; underside densely hairy, dotted with glands visible with a hand lens. Petioles 10-17 mm long. Three conspicuous main veins running from near base to tip. Have a pungent odour when crushed. Young leaves may be partly purplish.

Flowers

Inflorescence axillary or terminal panicles of heads. Flowers ca. 5 mm diameter, white, pink or purple; ray florets absent; bracts green, 2-9 mm long.

Fruit

A nut, ca. 4-5 mm long, pappus of pale brown plumes.

Seedlings

Features not available.

Distribution and Ecology

An introduced species and occurs in NEQ. Altitudinal range from near sea level to 30 m. Found in and on the edges of rainforest and open forest and woodlands.

Natural History

A declared noxious weed. Considered to be one of the world's worst weeds.

Shrub (woody or herbaceous, 1-6 m tall)

X

Vine

X

RFK Code

3582