<i>Celtis sinensis</i> Pers. (Ulmaceae) naturalised in northern South Africa and keys to distinguish between <i>Celtis</i> species commonly cultivated in urban environments

Background: Alien Celtis species are commonly cultivated in South Africa. They are easily confused with indigenous C. africana Burm.f. and are often erroneously traded as such. Celtis australis L. is a declared alien invasive tree. Celtis sinensis Pers. is not, but has become conspicuous in urban op...

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Main Authors: Stefan J. Siebert, Madeleen Struwig, Leandra Knoetze, Dennis M. Komape
Format: Article
Language:English
Published: South African National Biodiversity Institut 2018-03-01
Series:Bothalia: African Biodiversity & Conservation
Subjects:
Online Access:https://abcjournal.org/index.php/abc/article/view/2288
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author Stefan J. Siebert
Madeleen Struwig
Leandra Knoetze
Dennis M. Komape
author_facet Stefan J. Siebert
Madeleen Struwig
Leandra Knoetze
Dennis M. Komape
author_sort Stefan J. Siebert
collection DOAJ
description Background: Alien Celtis species are commonly cultivated in South Africa. They are easily confused with indigenous C. africana Burm.f. and are often erroneously traded as such. Celtis australis L. is a declared alien invasive tree. Celtis sinensis Pers. is not, but has become conspicuous in urban open spaces. Objectives: This study investigates the extent to which C. sinensis has become naturalised, constructs keys to distinguish between indigenous and cultivated Celtis species, and provides a descriptive treatment of C. sinensis. Methods: Land-cover types colonised by C. sinensis were randomly sampled with 16 belt transects. Woody species were identified, counted and height measured to determine the population structure. C. africana and the three alien Celtis species were cultivated for 2 years and compared morphologically. Results: Celtis sinensis, Ligustrum lucidum and Melia azedarach were found to be alien species, most abundant in urban areas. The population structure of C. sinensis corresponds to that of the declared invasive alien, M. azedarach. Although C. africana occurs naturally, it is not regularly cultivated. This is ascribed to erroneous plantings because of its resemblance to juvenile plants of C. sinensis. Keys are provided to identify Celtis species based on leaf shape and margin, and drupe characters. Conclusion: Celtis sinensis is naturalised in central South Africa, especially in urban open spaces and beginning to colonise natural areas. It is flagged as a species with invasive potential. Characteristics of the leaves and fruits allow for accurate identification of indigenous and alien Celtis species, both as juvenile or adult trees.
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spelling doaj.art-4ecf2038a01c4488adaf77f651e8b68f2022-12-21T18:38:46ZengSouth African National Biodiversity InstitutBothalia: African Biodiversity & Conservation0006-82412311-92842018-03-01481e1e910.4102/abc.v48i1.22881925<i>Celtis sinensis</i> Pers. (Ulmaceae) naturalised in northern South Africa and keys to distinguish between <i>Celtis</i> species commonly cultivated in urban environmentsStefan J. Siebert0Madeleen Struwig1Leandra Knoetze2Dennis M. Komape3Unit for Environmental Sciences and Management, North-West UniversityUnit for Environmental Sciences and Management, North-West University, South Africa; Department of Soil, Crop and Climate Sciences, University of the Free State, South Africa; Department of Botany, National MuseumUnit for Environmental Sciences and Management, North-West UniversityUnit for Environmental Sciences and Management, North-West UniversityBackground: Alien Celtis species are commonly cultivated in South Africa. They are easily confused with indigenous C. africana Burm.f. and are often erroneously traded as such. Celtis australis L. is a declared alien invasive tree. Celtis sinensis Pers. is not, but has become conspicuous in urban open spaces. Objectives: This study investigates the extent to which C. sinensis has become naturalised, constructs keys to distinguish between indigenous and cultivated Celtis species, and provides a descriptive treatment of C. sinensis. Methods: Land-cover types colonised by C. sinensis were randomly sampled with 16 belt transects. Woody species were identified, counted and height measured to determine the population structure. C. africana and the three alien Celtis species were cultivated for 2 years and compared morphologically. Results: Celtis sinensis, Ligustrum lucidum and Melia azedarach were found to be alien species, most abundant in urban areas. The population structure of C. sinensis corresponds to that of the declared invasive alien, M. azedarach. Although C. africana occurs naturally, it is not regularly cultivated. This is ascribed to erroneous plantings because of its resemblance to juvenile plants of C. sinensis. Keys are provided to identify Celtis species based on leaf shape and margin, and drupe characters. Conclusion: Celtis sinensis is naturalised in central South Africa, especially in urban open spaces and beginning to colonise natural areas. It is flagged as a species with invasive potential. Characteristics of the leaves and fruits allow for accurate identification of indigenous and alien Celtis species, both as juvenile or adult trees.https://abcjournal.org/index.php/abc/article/view/2288Celtis sinensisnaturalisedinvasiveHighveldgardenurban open space
spellingShingle Stefan J. Siebert
Madeleen Struwig
Leandra Knoetze
Dennis M. Komape
<i>Celtis sinensis</i> Pers. (Ulmaceae) naturalised in northern South Africa and keys to distinguish between <i>Celtis</i> species commonly cultivated in urban environments
Bothalia: African Biodiversity & Conservation
Celtis sinensis
naturalised
invasive
Highveld
garden
urban open space
title <i>Celtis sinensis</i> Pers. (Ulmaceae) naturalised in northern South Africa and keys to distinguish between <i>Celtis</i> species commonly cultivated in urban environments
title_full <i>Celtis sinensis</i> Pers. (Ulmaceae) naturalised in northern South Africa and keys to distinguish between <i>Celtis</i> species commonly cultivated in urban environments
title_fullStr <i>Celtis sinensis</i> Pers. (Ulmaceae) naturalised in northern South Africa and keys to distinguish between <i>Celtis</i> species commonly cultivated in urban environments
title_full_unstemmed <i>Celtis sinensis</i> Pers. (Ulmaceae) naturalised in northern South Africa and keys to distinguish between <i>Celtis</i> species commonly cultivated in urban environments
title_short <i>Celtis sinensis</i> Pers. (Ulmaceae) naturalised in northern South Africa and keys to distinguish between <i>Celtis</i> species commonly cultivated in urban environments
title_sort i celtis sinensis i pers ulmaceae naturalised in northern south africa and keys to distinguish between i celtis i species commonly cultivated in urban environments
topic Celtis sinensis
naturalised
invasive
Highveld
garden
urban open space
url https://abcjournal.org/index.php/abc/article/view/2288
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