ARGENTINE FLEABANE

Erigeron bonariensis

(Formerly: Conyza bonariensis)
Daisy & Dandelion Family [Asteraceae]

month8jun month8june month8jul month8july month8aug month8sep month8sept

Pappus: pappusZpossible (greyish or off-white, simple)
pappus8jul pappus8july pappus8aug pappus8sep pappus8sept pappus8oct

status
statusZneophyte
flower
flower8white
inner
inner8yellow
petals
petalsZMany
type
typeZclustered
type
typeZtubular
stem
stem8round
stem
stem8fluted
sex
sexZbisexual

15th Sept 2018, a pavement, Coventry. Photo: © Diane Napier
It grows up to 60cm high. The flowers are on long lateral branches.


15th Sept 2018, a pavement, Coventry. Photo: © Diane Napier
The flowers lack ray florets (aka ligules).


15th Sept 2018, a pavement, Coventry. Photo: © Diane Napier
Those flowers on the right have developed a ripe pappus with seeds at the centre.


15th Sept 2018, a pavement, Coventry. Photo: © Diane Napier
The stems are greyish-green and hairy.


15th Sept 2018, a pavement, Coventry. Photo: © Diane Napier
Some yellowish inner disc florets at the top have not yet turned to white parachutes for the seeds.


15th Sept 2018, a pavement, Coventry. Photo: © Diane Napier
The seed parachutes are greyish-white in colour (but are not tipped red (as they are on Bilboa's Fleabane. Instead the phyllaries [aka bracts] are conspicuously tipped with red). At the time of fruiting, as in these examples, the width of the capitula (comprising all the green/red bracts cum phyllaries) are between 7 to 11mm wide.


15th Sept 2018, a pavement, Coventry. Photo: © Diane Napier
The leaves are long linear and a bit grass-like, but that is possibly not a differentiating feature.


15th Sept 2018, a pavement, Coventry. Photo: © Diane Napier
The stem is covered in short hairs curved towards the tops on both the stem and the leaves, angular and with shallow grooves. Some hairs longer than most others.


Many similarities to : Guernsey Fleabane (Erigeron sumatrensis), Bilbao's Fleabane (Erigeron floribundus) and to Canadian Fleabane (Erigeron canadensis) which are all in the same genus.

No relation to : Argentine-pear (Dunalia australis), Argentine Barley (Hordeum euclaston), Argentine Pepperwort (Lepidium bonariense), Argentine Needle-grass (Nassella tenuissima), Argentine Dock (Rumex frutescens) nor to Argentine Cockelbur (Xanthium ambrosioides) [plants with similar names belonging to differing families].

Argentine Fleabane is a recent alien introduction (formerly it was accidentally brought into the UK on wool [presumably from Argentina] and became naturalised in Middlesex since 1993, but is now slowly spreading around the UK. It cannot be differentiated from Guernsey Fleabane by either the glands or their stickiness despite what other sources may say. Argentine Fleabane is more sensitive to frosts than either of its two look-e-like-ee's Guernsey Fleabane and Bilbao's Fleabane. On all three species, Argentine, Bilbao's and Guernsey Fleabanes, the disc florets have 5 lobes whereas Canadian Fleabane usually has 4 lobes (but occasionally 5 lobes). Altogether, all 4 of these Fleabanes mentioned here are a difficult group to differentiate, with the examples found in Britain being a smaller subset of those found in America.


  Conyza bonariensis  ⇐ Global Aspect ⇒ Asteraceae  

Distribution
 family8Daisy & Dandelion family8Asteraceae
 BSBI maps
genus8Conyza
Conyza
(Fleabanes)

ARGENTINE FLEABANE

Erigeron bonariensis

(Formerly: Conyza bonariensis)
Daisy & Dandelion Family [Asteraceae]