T.E.R:R.A.I.N - Taranaki Educational Resource: Research, Analysis and Information Network

Conyza bonariensis (Wavy-leaved Fleabane)

Kingdom: Plantae
(Unranked): Angiosperms
(Unranked): Eudicots
(Unranked): Asterids
Order: Asterales
Family: Asteraceae
Tribe: Astereae
Genus: Conyza
Species: C. bonariensis
Binomial name: Conyza bonariensis
Common Name(s): Wavy-leaved fleabane, Flax-leaf Fleabane and Argentine Fleabane.

Wavy-leaved fleabane is an erect perennial exotic from temperate South America and is found throughout the tropics and subtropics as a widespread weed of cultivated land, garden areas, wasteland and roadsides. Found from spring to autumn, most prevalent in summer months.
It is instantly recognisable by its blue-green foliage, very narrow, undulate leaves, and purple-tipped involucral bracts. C. bonariensis grows up to 75cm in height and it has narrow lanceolate leaves which are grey to green in colour. The leaves are covered with stiff hairs, including long hairs near the apex of the bracts.
It has erect stems with stiff hairs, branching extensively at the base, decreasing upwards.
Flowers are numerous on poorly arranged pyramidal panicles (much-branched inflorescence). Flowers occur at the ends of the branches. Surrounding each flower are involucral (bell-shaped leaf-like) bracts 3-5mm in length, the inside of each bract is white sometimes tinged purple or red. The cypsela (fruit) is a linear-shaped seed approximately 1.5mm long, straw coloured, covered in hairs with 16-20 noticeably longer at the top that are white or pink.

Fruiting stage shows long straw coloured pappus attached to the seeds. 

The wavey leaves

The hairy leaves and stem

The root system

Thanks to Wikipedia for text and information: https://creativecommons.org/licenses/by-sa/3.0/