Flowers and leaves. Photo: Don Wood, south coast, NSW

Seed heads. Photo: Russell Best, north of Melbourne, Vic

Plants. Photo: James Booth, north of Melbourne, Vic

Leaves. Photo: James Booth, north of Melbourne, Vic

Common Name

Fireweed, Annual Fireweed

Family

Asteraceae

Notes

Annual forb to 2m tall with a woody base. Leaves alternating up the stems, 4-20cm long, 10-30mm wide, sometimes larger, flat, hairy to slightly hairy. Leaves in the middle third of the stems with basal lobes, somewhat stem clasping, margins coarsely toothed to deeply lobed, the lobes often toothed. Uppermost leaves flat to linear, margins toothed or appearing entire due to rolling. Flower heads top-shaped to almost globular, green to purple, with yellow to orange florets, and 0 petals, in open groups, often of 50-300 flower heads per stem, at the tops of the stems. Rare Vic (ssp. longifructus).

Senecio glomeratus ssp. glomeratus has medium to dark red-brown seeds 1-1.7mm long. Hairs on the seed usually more than 5mm long. Seeds best seen with a low power microscope. The bases of the flower heads are often purple.

Senecio glomeratus ssp. longifructus has greenish or olive seeds 1.3-2.2mm long. Hairs on the seed usually less than 5mm long. Seeds best seen with a low power microscope. The bases of the flower heads are usually green.

Hybridisation between Senecio minimus and either Senecio glomeratus ssp. glomeratus or Senecio glomeratus ssp. longifructus is likely.

The description is mainly derived from the description in Thompson, I.R., (2004) Taxonomic studies of Australian Senecio (Asteraceae): 1. The disciform species. Muelleria 19: 143, 145

PlantNET description:  http://plantnet.rbgsyd.nsw.gov.au/cgi-bin/NSWfl.pl?page=nswfl&lvl=sp&name=Senecio~glomeratus