The Deschampsia cespitosa (Poaceae) complex in Great Britain and Ireland
Keywords:Taxonomy; chromosome numbers; ancient woodland; vivipary in grasses; phytogeography
The Deschampsia cespitosa complex in Great Britain and Ireland is shown to consist of three distinct species, one represented by three variants:
(1) D. parviflora (Thuill.) P. de Beauvois, a shade tolerant diploid species with spikelets less than 3.5 mm, of heavy clay or flushed soils in ancient woodland, principally from East Inverness-shire and central Scotland southwards;
(2) D. alpina (L.) Roemer and Schultes, a small, tetraploid, viviparous species, with hooded leaf-tips and brittle plantlets with appressed glumes and lemmas, of wet, open habitats at high altitudes in the Scottish Highlands and (rarely) in Ireland;
(3) D. cespitosa (L.) P. de Beauvois, represented by three variants,
(a) a seed-bearing diploid found primarily in peripheral coastal areas and islands in northern and western Scotland and on mountains in the central and northern Scottish Highlands and Teesdale,
(b) a seed-bearing tetraploid which is the common cytotype of the species in unshaded and many woodland habitats from central Scotland southwards,
(c) a viviparous tetraploid, which is a form of the seed-bearing tetraploid, found in the south-west Scottish Highlands, English Lake District and Snowdonia and is probably unique to Britain.
Suspected viviparous triploid hybrids were found between diploid D. cespitosa and both D. alpina and tetraploid D. cespitosa.
Copyright (c) 2022 Hugh McAllister, Andy Amphlett
This work is licensed under a Creative Commons Attribution 4.0 International License.
Copyright and licence: Authors (or their employers) retain their copyright in articles and images published in British & Irish Botany and are not required to assign this to the Botanical Society of Britain & Ireland (BSBI). All that BSBI requires from authors is a license to publish the article in British & Irish Botany and make it freely available to all in pdf format under the terms of Creative Commons Attribution 4.0 International Public License, which also enables BSBI to reproduce components of the article in other BSBI outputs (eg. BSBI News, the BSBI website and/or the BSBI News & Views blog) for publicity purposes. The licence code can be accessed here: