[3][4][5] Senecio quadridentatus is an annual or perennial herbaceous flowering plant in the family Asteraceae.

[6][7] This erect plant, Senecio quadridentatus, is an annual or short-lived perennial herb up to around 1m tall.

[9][10] Its stems are branched from or near the hard woody base, covered with thick white fine hair-like filaments,[7][8] becoming thin with age.

[8] Lower and middle stem leaves are basically evenly arranged and similar in size, about 4–12 cm long and 1.5-6 mm wide.

[12] It reported that Senecio quadridentatus found in an urban area in Christchurch in New Zealand may be caused by the distribution of seeds by the wind from Port Hill not far away.

It is mainly a short-lived perennial and it can reshoot after disturbances events happened or it can grow as an annual where conditions are tougher.

[11] Its seeds can lie dormant on the ground for a couple of years, germinating quickly after summer heat, fire or other disturbances.

[12] Chromatomyia syngenesiae (ragwort leafminer), an adventive fly from Europe, is a leaf miner in Compositae (daisy family), including S.

[15][16] S. quadridentatus is a host plant of magpie moth larvae (Nyctemera annulata) seen along the Summit Road on the Port Hills in Christchurch.

[9][12] Cotton comes from the white cottony appearance of the plants and fireweed results from the abundance of the species on the places where forests burned or other disturbance events happened.

The remarkable features that distinguish it from others are the cottony lower surface and entire or distantly toothed margin.

[6] The leaves of Senecio gomeratus are pinnately lobate, with few serrate on each lobe and with white woolly hairs on both leaf surfaces.

[9] It is rare to find the descriptions of the life habits and lifecycle of cotton fireweed in New Zealand in detail.