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


Senecio bipinnatisectus (Australian fireweed)

Kingdom:   Plantae
(Unranked): Angiosperms
(Unranked): Eudicots
(Unranked): Asterids
Order:       Asterales
Family:      Asteraceae
Subfamily: Asteroideae
Tribe:        Senecioneae
Genus:      Senecio
Species:     S. bipinnatisectus
Scientific name: Senecio bipinnatisectus
Synonyms: Erechtites atkinsoniae, Senecio atkinsoniae
Common names: Australian fireweed, Commonwealth Weed

Senecio bipinnatisectus is endemic to Australia and occurs in NE Queensland and southwards as far as south-eastern Queensland and south-eastern New South Wales.
This weed is common in the North Island but very rare in the South Island. It grows in clearings and along roads, coastal and wet places.

Senecio bipinnatisectus is an erect, annual or short-lived perennial herb, up to c. 2 m tall. It stems usually glabrous or with a few fine scattered hairs. It usually flowers and fruits as a shrub 1-3 m tall.
The leaf blades (about 3-10 x 1-6 cm) are intricately divided and dissected and the petioles are very short. Both the upper and lower surfaces are clothed in short +/- erect hairs. The reduced leaves resembling stipules, present near the base of each petiole.
Flowering occurs December to June and the inflorescence is a cyme of heads. The flowers are a greenish yellow disc about 2mm in diameter with out any florets. The corolla tube is slender and is about 10 mm long, the corolla lobes about 0.25 mm long. The anthers +/- fused to form a tube and the filaments are free. The pollen is yellow.
The fruits are ribbed cylindrical achene about 2mm long with a pappus (feathery bristles) about 6mm long.