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Auteur Mark A. Spencer |
Documents disponibles écrits par cet auteur (3)
trié(s) par (Pertinence décroissant(e), Titre croissant(e)) Affiner la rechercheAchene Morphology of British and Irish Mayweeds and Chamomiles : implications for taxonomy and identification / Chris A. Skilbeck in British & Irish Botany, vol. 1, n°2 (Année 2019)
Titre : Achene Morphology of British and Irish Mayweeds and Chamomiles : implications for taxonomy and identification Type de document : texte imprimé Auteurs : Chris A. Skilbeck, Auteur ; Iris Lynch, Auteur ; Maggie Ellenby, Auteur ; Mark A. Spencer, Auteur Année de publication : 2019 Article en page(s) : pp. 128-166 Langues : Anglais (eng) Catégories : [Espèces (in biblio)] Anthemis
[Espèces (in biblio)] Chamaemelum
[Espèces (in biblio)] Cota
[Espèces (in biblio)] Matricaria
[Espèces (in biblio)] TripleurospermumMots-clés : morphologie akène détermination Résumé : "Whilst determining the mayweed and chamomile specimens in the Natural History Museum’s British & Irish Herbarium we decided to produce a photographic guide and key to assist in the determination of these plants using achene morphology. Because of our observations, and in line with North American treatments, we propose recognising Matricaria discoidea subsp. discoidea and M. discoidea subsp. occidentalis as separate species. We also discuss possible introgression from Tripleurospermum maritimum subsp. phaeocephalum in northern parts of Birtain and Ireland, the implications for the taxonomy of Anthemis/Cota and Chamaemelum and the usefulness of achene glands in determination of specimens. Finally we consider the problems that may arise when using immature achenes and herbarium specimens for determination and we discuss the usefulness of being aware of changes in colour and form that occur during development, particularly as many collected specimens lacked ripe capitula." (source : auteurs) Type de publication : périodique Référence biblio : Skilbeck C., Lynch I., Ellenby M., Spencer M., 2019 - Achene Morphology of British and Irish Mayweeds and Chamomiles : implications for taxonomy and identification. British & Irish Botany, 1 (2) : 128-166. ID PMB : 69683 En ligne : https://britishandirishbotany.org/index.php/bib/article/view/16/30 Format de la ressource électronique : document Permalink : http://www.cbnbrest.fr/catalogue_en_ligne/index.php?lvl=notice_display&id=69683
in British & Irish Botany > vol. 1, n°2 (Année 2019) . - pp. 128-166[article]Exemplaires(0)
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Titre : Pedunculate Club-rush Bolboschoenus laticarpus (Cyperaceae) ? an overlooked native or a spreading neophyte ? Type de document : texte imprimé Auteurs : Frederick J. Rumsey, Auteur ; Helena J. Crouch, Auteur ; Richard Lansdown, Auteur ; Mark A. Spencer, Auteur Année de publication : 2019 Article en page(s) : pp. 91-106 Langues : Anglais (eng) Catégories : [ZG] Royaume-Uni
[Espèces (in biblio)] Bolboschoenus
[Thèmes] TaxonomieMots-clés : aire de répartition anatomie fruit statut écologie Résumé : "Bolboschoenus laticarpus Marhold, Hroudová, Zákravský & Ducháček (for which we suggest the common name Pedunculate Club-rush) is reported from the British Isles and the characters which distinguish it from B. maritimus (L.) Palla are given. The known English distribution is presented and placed in its wider geographical context. The ecology and history of this species in Britain are outlined and its likely status is considered. B. laticarpus is locally abundant and widely distributed in a range of natural and artificial habitats, particularly within the Somerset Levels and also in the flood plains of some larger rivers, where it is now known to have been long persistent. B. laticarpus appears to be a successful colonist, having arrived recently in several newly created, artificial habitats. The mode of introduction is unknown but believed to be natural, and indeed elsewhere in Europe it is reportedly increasing within its natural range, perhaps as a consequence of changes in land-use, eutrophication and potentially climate. We therefore regard it as a native taxon." (source : auteurs) Type de publication : périodique Référence biblio : Rumsey F., Crouch H.-J., Lansdown R., Spencer M., 2019 - Pedunculate Club-rush Bolboschoenus laticarpus (Cyperaceae) ? an overlooked native or a spreading neophyte ? British & Irish Botany, 1 (2) : 91-106. ID PMB : 69681 En ligne : https://britishandirishbotany.org/index.php/bib/article/view/17/23 Format de la ressource électronique : document Permalink : http://www.cbnbrest.fr/catalogue_en_ligne/index.php?lvl=notice_display&id=69681
in British & Irish Botany > vol. 1, n°2 (Année 2019) . - pp. 91-106[article]Exemplaires(0)
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Titre : Typification of 18th Century names in Carex sect. Rhynchocystis (Cyperaceae) : Carex pendula and allies Type de document : texte imprimé Auteurs : Pedro Jiménez -Mejías, Auteur ; Mónica Míguez, Auteur ; Mark A. Spencer, Auteur ; Charles E. Jarvis, Auteur ; Santiago Martin-Bravo, Auteur Année de publication : 2017 Article en page(s) : pp. 973-975 Langues : Anglais (eng) Catégories : [Espèces (in biblio)] Carex pendula Mots-clés : épitypification Hudson lectotypification Linnée Scopoli Carl Ludwig Willdenow Résumé : "According to recent molecular and morphological studies, the apparently homogeneous Carex pendula has been shown to include two different species. One species is distributed across western Europe and the Mediterranean, whereas the other ranges from central and eastern Europe to the Caucasus and northern Iran. Three different names have been considered synonyms of C. pendula: C. agastachys, C. maxima, and C. mutabilis. Here C. pendula is shown to apply to the western taxon, and C. agastachys to be the oldest name for the eastern taxon. An epitype is designated for C. pendula given the insufficient level of detail provided by the previously designated neotype." (source : auteurs) Type de publication : périodique Référence biblio : Jiménez -Mejías P., Míguez M., Spencer M., Jarvis C., Martin-Bravo S., 2017 - Typification of 18th Century names in Carex sect. Rhynchocystis (Cyperaceae) : Carex pendula and allies. Taxon, 66 (4) : 973-975. ID PMB : 68939 DOI : 10.12705/664.12 Permalink : http://www.cbnbrest.fr/catalogue_en_ligne/index.php?lvl=notice_display&id=68939
in Taxon > vol. 66, n°4 (Année 2017) . - pp. 973-975[article]Exemplaires(0)
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