Erigeron bonariensis

2. Erigeron bonariensis L. (syn.: E. crispus Pourr., E. linifolius Willd., Conyza bonariensis (L.) Croncq., C. ambigua DC.) (S-Am.) – A very rare but locally naturalised alien. First recorded as a regular but ephemeral wool alien in the Vesdre valley between 1892 and 1940. In 1981 seen on a coal mine heap in Wasmes (Havrenne 1982). From the 1990’s onwards increasingly recorded in the larger cities in Flanders (especially Antwerpen and Gent, furthermore also seen in Brugge, Kontich, Zeebrugge,…) (Verloove & Boullet 2001, Verloove 2002). In 2011 also recorded for the first time in Brussel. Erigeron bonariensis usually persists for some time but most often behaves like an ephemeral alien. However, in Antwerpen is has recently become naturalised and is now widespread in the northern part of the city (close to the old port) and further extends to the rest of the city. In 2013 it was reported to have spread to the south: a large population was recorded in the city of Willebroek.

Erigeron bonariensis is confined to dry, sun-exposed, ruderal places, especially foot of walls, pavements, fences, sometimes also in disused railway yards. It is obviously more thermophilous than its related species and only occurs in urban areas in Belgium.

A hybrid with Erigeron canadensis, E. x foucaudi B. Bock (syn.: Conyza x mixta Foucaud et Neyraut), has been recorded among its parents on a disused railway yard in Antwerpen in 2002. It is perfectly intermediate between its parents. The name Erigeron flahaultianus Thell. (syn.: Conyza flahaultiana Sennen) has been misapplied for this hybrid. The latter is a synonym of either Erigeron sumatrensis or E. floribunda.

 Antwerpen, urban area, October 2009, R. Barendse Lanaken (Neerharen), gravelly border of river Maas, October 2010, R. Barendse

Herbarium specimen

 


Selected literature:

Ciortan I. & Negrean G. (2012) Conyza bonariensis, a new plant with invasive character in Romanian flora. Annales Univ. Craiova 17: 743-748. [available online at: http://www.anucraiova.3x.ro/cont/2012-2/126_NegreanG_2.pdf]

Havrenne A. (1982) Observations botaniques sur les terrils de la province de Hainaut. Nat. Mosana 35(2-3): 68-69.

Negrean G. & Ciortan I. (2012) Conyza bonariensis, a new plant with invasive character in Romanian flora. Analele Universităţii din Craiova - Biologie, Horticultura, Tehnologia Prelucrarii Produselor Agricole, Ingineria Mediului 17: 743-748. [available online at: http://www.specii-invazive.ro/system/files/negrean-ciortan-2012-conyza-bonariensis-a-new-plant-with-invasive-character-in-romanian-flora.pdf]

Nesom G.L. (2018) Erigeron floribundus and E. sumatrensis (Asteraceae) in the USA and Mexico. Phytoneuron 2018-27: 1–19. [available online at: http://www.phytoneuron.net/2018Phytoneuron/27PhytoN-Conyzasumatrensis.pdf]

Palmer J.R. (1984) Conyza bonariensis (L.) Cronq. in Central London. BSBI News 37: 16.

Verloove F. (2002) Ingeburgerde plantensoorten in Vlaanderen. Mededeling van het Instituut voor Natuurbehoud n° 20: 227 p.

Verloove F. & Boullet V. (2001) Conyza bonariensis en Conyza sumatrensis: recent ingeburgerd in België? Dumortiera 77: 2-8.

Scratchpads developed and conceived by (alphabetical): Ed Baker, Katherine Bouton Alice Heaton Dimitris Koureas, Laurence Livermore, Dave Roberts, Simon Rycroft, Ben Scott, Vince Smith