Senecio madagascariensis

Madagascan Fireweed, Fireweed at Braddon, ACT

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Identification history

	Senecio madagascariensis	18 Oct 2019	MichaelMulvaney
	Senecio madagascariensis	17 Oct 2019	Mike

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Significant sighting

MichaelMulvaney noted:

18 Oct 2019

New infestation of this highly invasive plant

User's notes

Maybe I am just suspicious about stray daisies.

4 comments

BettyDonWood wrote:

18 Oct 2019

One of the diagnostics of Senecio madagascariensis is the number of bracts on the flower head behind the ‘petals’ - 19-21. The local yellow Senecio, pinnatifolius var. alpinus, which I would expect at altitudes much higher than Canberra, has about 13, but sometimes about 20 bracts.
The character the Vicflora key to Senecio uses to separate madagascariensis from pinnatifidus: madagascariensis - bracteoles not or barely overlapping the base of the involucre; neither bracts nor bracteoles conspicuously black-tipped; cypselas (seeds) 1.5-2.2 mm long, 0.3-0.5 mm diameter. Pinnatifolius: bracteoles overlapping the base of the involucre; bracts and bracteoles conspicuously black-tipped; cypselas (seeds) 1.6-4.5 mm long, 0.5-0.8 mm diameter.

Mike wrote:

18 Oct 2019

More likely to be an invasive plant making its way down the tram tracks from Gungahlin. I don't know if I can get back to count the bracts or look for black tips. If it is the invasive one I don't want to see the seeds.

BettyDonWood wrote:

18 Oct 2019

Probably better to bag it and take it to the herbarium.

MichaelMulvaney wrote:

19 Oct 2019

City Services has/is taking action on removing this plant. Steve Taylor also passed on the tip that
Firewwed ‘usually’ has 13 to 15 ray florets (but can be more) and has 19-21 involucral bracts and 8 – 12 bracteoles http://plantnet.rbgsyd.nsw.gov.au/cgi-bin/NSWfl.pl?page=nswfl&lvl=sp&name=Senecio~madagascariensis

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