Erigeron sumatrensis

Description

When fully grown (in summer or autumn), Erigeron sumatrensis reaches one to two metres in height. Flowers are white rather than purple-pink. Its leaves are like dandelion leaves, but longer, thinner and more like primrose leaves in colour and texture. Its seeding heads are like dandelions, but straw coloured and smaller. In certain countries the plant has started to exhibit resistance to herbicides.

Distribution

It probably originates from South America, but is now naturalised in North America, Europe, Africa, Asia, and Australasia. It poses a significant threat to wildlife conservation areas and other reserves. In Britain, of the non-native former Conyza species, it is the second most abundant (after Erigeron canadensis) and is typically found in London and the South East of England. It was first recorded in London by Brian Wurzell in 1984, and noted in France at Saint-Sozy (Dordogne) in 2006.

Taxonomic note

Older literature such as Flora of Turkey may quote Conyza albida Willd. ex Spreng. intending what is now E. sumatrensis Retz., and should be taken as such; likewise other literature references may do so; the type has subsequently been revised and Conyza albida Willd. ex Spreng. is now viewed as a synonym for Erigeron floribundus (Kunth) Sch.Bip.

Photographic description

Erigeron sumatrensis from Antalya by D Merrick 16.jpg|Tall and tending to end up leaning over

Erigeron sumatrensis from Antalya by D Merrick 12.jpg|Side phyllaries hairy and green, without red tips, and lacks prominent white petals, which may have a purple tinge

Erigeron sumatrensis from Antalya by D Merrick 13.jpg|Head from above, ray petals with purple tinge

Erigeron sumatrensis from Antalya by D Merrick 14.jpg|Individual flower from within head, 5-petalled

Erigeron sumatrensis from Antalya by D Merrick 15.jpg|Individual flower from within head, 5-petalled

Erigeron sumatrensis from Antalya by D Merrick 17.jpg|Base leaves quite broad, lobey and hairy, but green-looking not conspicuously grey

Erigeron sumatrensis from Antalya by D Merrick 19.jpg|Colony of rosettes

Erigeron sumatrensis from Antalya by D Merrick 18.jpg|Emerging plant, green-looking

Erigeron sumatrensis from Antalya by D Merrick 05.jpg|Flowering whilst still small

Erigeron sumatrensis from Antalya by D Merrick 24.jpg|Stem leaf

Erigeron sumatrensis from Antalya by D Merrick 08.jpg|Stem leaf base

Erigeron sumatrensis from Antalya by D Merrick 04.jpg|Stem leaf near tip

Erigeron sumatrensis from Antalya by D Merrick 02.jpg|Stem leaf underside

Erigeron sumatrensis from Antalya by D Merrick 03.jpg|Stem leaf underside

Erigeron sumatrensis from Antalya by D Merrick 06.jpg|Stem

Erigeron sumatrensis from Antalya by D Merrick 11.jpg|Inflorescence prior to heads expanding with pappus

Erigeron sumatrensis from Antalya by D Merrick 21.jpg|Seeding

Conyza sumatrensis flowerhead2 (13346716844).jpg

Conyza sumatrensis leaves3 (13346498873).jpg

Erigeron sumatrensis sl14.jpg

References

References

1. [https://www.biodiversitylibrary.org/page/11159722#page/98/mode/1up Pruski, J.F. & G. Sancho. 2006. ''Conyza sumatrensis'' var. ''leiotheca'' (Compositae: Astereae), a new combination for a common neotropical weed. Novon 16(1): 96–101]
2. {{BSBI 2007
3. See pictures at [http://www.iewf.org/weedid/Conyza_sumatrensis.htm International Environmental Weed Foundation]
4. [https://web.archive.org/web/20020420153136/http://www.weedscience.org/Case/Case.asp?ResistID=126 Sumatran Fleabane], Weedscience.org
5. [http://www.kuleuven-kortrijk.be/bioweb/?lang=en&detail=732&titel=Sumatran%20fleabane%20-%20Conyza%20sumatrensis Fleabane in Holland]
6. [http://www.zimbabweflora.co.zw/speciesdata/species.php?species_id=159010 Flora of Zimbabwe: ''Conyza sumatrensis'']
7. [http://www.botanic.jp/plants-aa/ooaret.htm Sumatran Fleabane in Japan]
8. [http://www.hear.org/pier/species/conyza_sumatrensis.htm Pacific Island Ecosystems at Risk (PIER): ''Conyza sumatrensis'']
9. "Fleabane in London".
10. Mark Galliott. (June 2006). "France – The Dordogne". Naturetrek Wildlife Holidays.
11. [http://www.phytoneuron.net/2018Phytoneuron/27PhytoN-Conyzasumatrensis.pdf ''Erigeron Floribundus'' and ''E. Sumatrensis'' (Asteraceae) In The USA And Mexico, 2018 by Guy L. Nesom], p16 in section on ''Erigeron floribundus''
12. [http://www.efloras.org/florataxon.aspx?flora_id=2&taxon_id=242422279 Flora of China, 苏门白酒草 su men bai jiu cao ''Erigeron sumatrensis'' Retzius]
13. (February 2023). "''Erigeron sumatrensis'' Retz.". [[Royal Botanic Gardens, Kew]].