Erigeron bonariensis vs canadensis vs sumatrensis

Key to species.

1 - Outer ligules distinctly exceeding the invulucre apex. The whole plant from glabrescent to hairy but with prevalent comparatively longer hairs: E. canadensis
1' - Outer ligules, if present, not exceeding the involucre apex. The whole plant densely hairy with few long hairs and prevalent short hairs: 2
2 - Middle cauline leaves lanceolate. Capitula usually narrower in upper half (pear-shaped) at flowering, rarely cylindrical. Plants columnar: E. sumatrensis
2' - Middle cauline leaves almost linear. Capitula usually not, or only slightly, narrower in upper half (barrel-shaped or cylindrical) at flowering or narrower (hybridization?). Plants columnar or with lateral branches equalling the main stem: E. bonariensis

Here a beautiful comparison of the three taxa (link suggested by @marcoschmidtffm )
http://www.blumeninschwaben.de/Zweikeimblaettrige/Korbbluetler/conyza.htm

1 - Ligule esterne distintamente superanti l'apice dell'involucro. Tutta la pianta da glabrescente a pelosa ma con prevalenza di peli relativamente più lunghi: E. canadensis
1 '- Ligule esterne, se presenti, non superanti l'apice dell'involucro. Tutta la pianta densamente pelosa con pochi peli lunghi e prevalenti peli corti: 2
2 - Foglie cauline mediane lanceolate. Capolini più stretti nella metà superiore (a forma di pera) alla fioritura. Piante di forma colonnare: E. sumatrensis
2 '- Foglie cauline mediane lineari o quasi. Capolini solitamente non, o solo leggermente, più ristretti nella metà superiore (a forma di botte o cilindrici) alla fioritura oppure più stretti (ibridazione?) nella metà superiore. Piante colonnari o con i rami laterali che eguagliano il fusto principale: E. bonariensis

Qui una bellissima comparazione tra i tre taxa (link suggerito da @marcoschmidtffm )
http://www.blumeninschwaben.de/Zweikeimblaettrige/Korbbluetler/conyza.htm

Literature:
http://alienplantsbelgium.be/content/erigeron
https://www.researchgate.net/profile/John_Pruski/publication/232686179_Conyza_sumatrensis_var_leiotheca_Compositae_Astereae_a_New_Combination_for_a_Common_Neotropical_Weed/links/55cb8e0308aeb975674c7de0/Conyza-sumatrensis-var-leiotheca-Compositae-Astereae-a-New-Combination-for-a-Common-Neotropical-Weed.pdf
http://real.mtak.hu/108954/1/03WirthCsiky.pdf

Posted by blue_celery blue_celery, September 03, 2020 17:53

Comments

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Thank you very much!

Posted by phlomis_2019 about 2 months ago (Flag)
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you're welcome

Posted by blue_celery about 2 months ago (Flag)
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Grazie. Molto utile. Ciao.

Posted by guglielmo_vacirca about 2 months ago (Flag)
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Di niente. Ciao

Posted by blue_celery about 2 months ago (Flag)
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@marcoschmidtffm beautiful comparison

Posted by blue_celery about 2 months ago (Flag)
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Thank you! It is very useful key.

Posted by davydovbotany about 2 months ago (Flag)
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Posted by optilete about 2 months ago (Flag)
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Many thanks! Very useful!

Posted by fabiocianferoni about 2 months ago (Flag)
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di niente

Posted by blue_celery about 2 months ago (Flag)
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@optilete is there an English version?

Posted by blue_celery about 2 months ago (Flag)

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