Plymouth Phil's picture

Conyza floribunda, Bilbao's Fleabane

Observed: 12th August 2013 By: Plymouth PhilPlymouth Phil’s reputation in PlantsPlymouth Phil’s reputation in PlantsPlymouth Phil’s reputation in PlantsPlymouth Phil’s reputation in Plants
Conyza floribunda, Bilbao's Fleabane

This plant is a widespread urban weed in parts of Plymouth. The plant used to be called Conyza bilbaoana, Bilbao's Fleabane, but in Stace 3 is now called C. floribunda. The plant has no connection with Bilbao in Spain. It is native to South America.

Species interactions

No interactions present.


spins's picture

Dear Phil

Here is a good source

C. canadensis has clearly projecting ligular florets, whilst in C. floribundus the phyllaries reach to the top of the flower head. This is the best way to tell them apart. Hairiness is not a usable feature, as both species are very variable.

Plymouth Phil's picture


Yes, this is an excellent web site full of interesting stuff. Quentin Groom, who is one of the high-ups at the BSBI seems to have some connection with the site.

I agree with what you say about Conyza canadensis having projecting ligular florets and that is probably the best way of identifying it. But I still maintain that there are useful differences in the hairs on the leaf margins and on the phyllaries that can help separate the species.

Best wishes,

spins's picture

Hi Phil

Something to look out for next year. I find that just looking at the flowers is all that is needed to ID these things and people (myself included) often get too distracted by very variable characteristics. Where I live in Belgium the 3 are very well established.

Cheers, spins.

spins's picture

I had a look at some of my own pictures

and you are right. Phyllaries do appear to be glabrous to the eye in C. floribundus. But in C. canadensis hairiness is variable. (C. floribunus rather feels rough to the touch, but so do a limited number of C. candensis). If all things well, I'll add some observations on here, next season. In the meanwhile, lots of pics down here C. bilbaoana (= floribundus) (most of which are mine)
C. sumatrensis

C. canadensis (you can set language to English) is a bit like this, but it is heavely moderated. There is also for the Netherlands.

Cheers, spins.