Edited by IJ Bennallick & DA Pearman
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BOTANICAL CORNWALL 2010 No. 14 Edited by I.J. Bennallick & D.A. Pearman BOTANICAL CORNWALL No. 14 Edited by I.J.Bennallick & D.A.Pearman ISSN 1364 - 4335 © I.J. Bennallick & D.A. Pearman 2010 No part of this publication may be reproduced, stored in a retrieval system, or transmitted in any form or by any means, electronic, mechanical, photocopying, recording or otherwise, without prior permission of the copyright holder. Published by - the Environmental Records Centre for Cornwall & the Isles of Scilly (ERCCIS) based at the- Cornwall Wildlife Trust Five Acres, Allet, Truro, Cornwall, TR4 9DJ Tel: (01872) 273939 Fax: (01872) 225476 Website: www.erccis.co.uk and www.cornwallwildlifetrust.org.uk Cover photo: Perennial Centaury Centaurium scilloides at Gwennap Head, 2010. © I J Bennallick 2 Contents Introduction - I. J. Bennallick & D. A. Pearman 4 A new dandelion - Taraxacum ronae - and its distribution in Cornwall - L. J. Margetts 5 Recording in Cornwall 2006 to 2009 – C. N. French 9 Fitch‟s Illustrations of the British Flora – C. N. French 15 Important Plant Areas – C. N. French 17 The decline of Illecebrum verticillatum – D. A. Pearman 22 Bryological Field Meetings 2006 – 2007 – N. de Sausmarez 29 Centaurium scilloides, Juncus subnodulosus and Phegopteris connectilis rediscovered in Cornwall after many years – I. J. Bennallick 36 Plant records for Cornwall up to September 2009 – I. J. Bennallick 43 Plant records and update from the Isles of Scilly 2006 – 2009 – R. E. Parslow 93 3 Introduction We can only apologise for the very long gestation of this number. There is so much going on in the Cornwall botanical world – a New Red Data Book, an imminent Fern Atlas, plans for a new Flora and a Rare Plant Register, plus masses of fieldwork, most notably for Natural England for rare plants on SSSIs, that somehow this publication has kept on being put back as other more urgent tasks vie for precedence. In view of this we have decided that if we are going to go forward we must clear the decks now, and have produced this number without some of the extra features that have adorned other recent issues. This includes photographs and some of the distribution maps that would complement the plant records. We promise that those will return in the next issue. The real lesson learnt is how much Rose Murphy did in compiling the previous 13 issues and how difficult (impossible?) it will be to replace her. In particular we regret the absence of her magisterial introductory „Progress Report‟, her overview of the year. But the task of covering most of five years, 2005 to 2009, would have been huge, and would only have further delayed this issue. However, reading through the papers that we have included, and in particular the vast numbers of interesting plant records in a county that we idly assume to have been well- botanised, we are encouraged to hope that there is enough of interest here for all our readers. Interesting additions to the Cornish Flora since 2005 in this edition are Sea Daffodil Pancratium maritimum which was found growing on sand dunes at Marazion Green and may well be native; the confirmation of Rosa tomentosa as present in Cornwall; and also the confirmation (and first known record) of the long suspected hybrid between Hypericum undulatum and H. tetrapterum, which has now been recorded in six sites in Cornwall with both parents. In late 2009 and 2010 there have been some notable refinds of native species that have not been seen for many years including Juncus subnodulosus, Centaurium scilloides and Phegopteris connectilis. The significance of these is too great NOT to include in this issue, and details and photos of these finds can be found on page 36. We hope that you will enjoy this issue and we look forward to producing Botanical Cornwall 15 in 2011, which will include an update on the Botanical Cornwall Group field trips since 2005, as well as other articles which we could not fit into this issue. Whilst we strive to ensure that this issue is error free, if you see any corrections or omissions that are needed please contact Ian Bennallick, co-ordinator of the Botanical Cornwall Group at Lower Polmorla, St Wenn, Bodmin, Cornwall, PL30 5PE or email [email protected]. We must sincerely thank Colin French, Len Margetts, Nicholas de Sausmarez and Rosemary Parslow for their articles, and Alex Lockton for so kindly formatting our drafts. Ian Bennallick and David Pearman Editors Note – errata for previous issues In Botanical Cornwall 12 (2003) Geoff Kitchener has pointed out an error that crept in towards the bottom of page 24 - "E. ciliatum or E. montanum" should have read "E. ciliatum or E. obscurum". In Botanical Cornwall 13 (2005) on page 20 where a list of „extinct plants of Cornwall‟ is given, Euphorbia peplus should read Euphorbia peplis - Euphorbia peplus is definitely NOT extinct in Cornwall! In the same issue on page 25 Atriplex pedunculata was included in a list of threatened plants in Cornwall. This was included erroneously so should be removed as it has never been a member of the Cornish flora. Tim Rich has also pointed out that the drawings of the stipules of Spergularia bocconei on page 51 are printed upside down. Paul Green has also noted that the Euphorbia maculata on page 111 should be E. thymifolia. 4 A new dandelion - Taraxacum ronae – and its distribution in Cornwall L. J. Margetts This recently described dandelion (Margetts 2007) belongs to the section Naevosa, members of which have leaves that are spotted or variously covered with dark mauve or black markings. It was first found in Cornwall in 1973, on a small relict part of Connor Downs, and subsequently in many other places in West Cornwall. A specimen from Penpol House, Feock, sent to the late C. C. Haworth, was thought by him to be the European species Taraxacum maculigerum and was forwarded by him to the Scandinavian specialist C. I. Sahlin for confirmation; but on the sheet containing this specimen (herb. A. J. Richards) there is a note from Sahlin to the effect that it was a new species and 'has nothing or little to do with T. maculigerum'. As a result, Chris Haworth coined the work-name T. 'non-maculigerum' for recording purposes and the Cornish plants were listed and mapped under this name in Botanical Cornwall No. 5 (1991). After Dr A. J. Richards had described a new Naevosa species - T. maculosum (Richards 1981) - the Cornish plants were thought to be a polliniferous form of that species, but later on Chris Haworth decided that they were conspecific with yet another of the Naevosa section - the northern T. drucei. The Cornish records were mapped as such in Dandelions of Great Britain and Ireland (Dudman & Richards 2000) and were also included under this name in the Flora of Cornwall (French, Murphy & Atkinson 1999), where the authorship of T. drucei is attributed incorrectly to A. J. Richards. The type specimens of T. drucei, in the Fielding-Druce herbarium (OXF), were collected by G. C. Druce in Ireland in 1921, and named by the pioneer taraxacologist H. Dahlstedt, whose Latin description is pasted on the sheet. They show quite a different plant from the Cornish material: the leaves are spathulate with a broad terminal lobe, the involucres are rounded at the base, and the achenes are more-or-less smooth. This species favours different habitats too - natural niches such as cliff-ledges and rocks - whereas T. ronae is more a plant of grassland and hedgebanks. Clearly the time had come for this south-west dandelion to be given a name; the one chosen was after the author's wife, in memory of those halcyon days spent together recording the various microspecies. T. ronae is not confined to Cornwall. It occurs infrequently in Devon, and extends to outlying parts of Dorset and South Somerset. A recent examination of Irish material from the Ulster Museum (BEL) shows that much of the material in the T. drucei folder there has to be re- labelled as T. ronae. It is more than likely that searches in Scilly and the Channel Islands would reveal its presence there too. In the field T. ronae is easy to separate from other members of the section Naevosa, such as the widespread T. euryphyllum and the endemic T. cornubiense. In the early season its leaves are narrow, glabrous and shiny, with long narrow petioles, and strongly flecked with dark markings; the scapes are usually pale below but purplish above, leaving a pale green zone just below the conical involucre. Unlike T. maculosum, with which it has been confused, it produces abundant pollen, and has styles and stigmas that are yellowish at first, becoming discoloured later. Moreover, T. maculosum has leaves which are distinctly and roughly hairy, a useful character in the fresh state. In Cornwall T. ronae is frequent in the northern 1 km squares of the Lizard Peninsula, where it favours the lower parts of Cornish hedges and the narrow grass verges below. Cornish material is often small, especially on soils that are shallow and lack suitable nutrients. The silhouette illustrated here shows well the leaf morphology of such plants. 5 Specimen of Taraxacum ronae 6 Records of T. ronae in Cornwall 10 km square 1 km square Locality Year West Cornwall v.c.1 SW42 SW4524 Lamorna Valley 1980 SW53 SW5338 Carbis Bay 1977 SW53 SW5037 Trink Hill 1977 SW53 SW5537 Lelant (2 sites) 1979 SW53 SW5131 edge of Marazion Marsh 1982 SW53 SW5133 plant nursery, Crowlas 1982 near Townshend (with A. L. Grenfell & K. L.