DI5TOIBUTI0N IvKPS SCHEI^IS. 



Jxane 1954 



The Society has laxmched a five years' scheme to produce an Atlas of DistrilDution 

 Maps of British floT/ering plants and ferns on a "basis of the presence or absence of 

 each species in the 10 kilometre grid squares of the Ordnance Survey National G-rid. 

 Thore are about 3,500 such scpaares and approximately 2,000 native species In the British 

 Flora; our task is therefore to accuunulate some 2,500,000 records for vascular plants 

 in a convenient form for map-making. In this task v/e need the co-operation of all 

 field "botanists, professional and amateur, in schools, local natural history societies 

 and universities alike. 



There are many ways in r/hich you could help. Here are a few:- 



(1) Existing plant lists, which can be localised, v/ould be gratefully received, and 

 could be proii5)tly returned if desired, 



(2) Similar lists coiald be con^tiled of the plants found in a particular 10 kilometre 

 grid square (one of the big squares of about 6" side on the 1" 0,8, map; or a 

 single sheet of the 2^" Q.S. map) » Some indication of locality and habitat 

 could bo given for the less common plants, e,g,:- 



Lyohnis flos-cuculi . marsh by river, X, Grid Ref: 52/326485 - 21.6,1953. 

 (5) Lists of plants gromjTg in, say, 6 particular habitats (e.g, a v/ood, a raeadov?, an 

 arable field, a roadside, a pond, and a marsh) could be made T/ithin the same 

 10 kilometre grid square. In this v/ay all the more common plants are likely to 

 be recorded^ Record Cards, on which are listed all species likely to be found 

 in a particular Region (groiip of vice-counties) are available. These can be 

 filled in quickly and easily in the field. Please indicate areas in which you 

 wo\ild be able to use such cards- 



(4) Precise localities (v/ith Grid Reference to 100 m.) of any rare or local plants 

 would be very useful; such information can if desired be treated as confidential. 

 Individual records, based on herbarium specimens or on field knowledge, could be 

 sent in on small record cards, which we can supply; or, if you prefer, in. the 

 form of a list. (The card index is to form the basis of a permanent recording 

 system for the Nature Conservancy, for v/hom this type of information is obviously 

 of great importance) . 



(5) Ecological data submitted v/ith field lists -iTill, where possible, be incorporated 

 in the records, and v/ould be welcomed, 



(6) Help v/ill particularly be needed in certain under-worked areas, which can be 

 suggested on request. 



Important Points^ 



(a) Correct identification is essential. If you have ary doubt, please use the 

 Society's system of referees. For any critical group, confirmation by a 

 specialist is desirable and in many cases necessary. It is not necessary to 

 make a corqplete list; omit any doubtful identifications. 



(b) Information on comnpn plants is more important to us than localities for raiities. 

 The simplest lists of roadside or field, carefully made, are exactly v^t ire need, 

 A specially-designed 'Common Species Record Card' is available; this v/ould be 

 suitable for the less experienced observer, 



(c) For purposes of standardisation, we prefer the nomenclature in Clapham, Tutin and 

 Warburg: Flora of the British Isles. If, hov/evcr, you r/ish to use aj^ other 

 reference v/ork (eg, Bentham & Hooker), it iTill be quite convenient to use your 

 data, provided wc know v/hich book you arc using. 



If you T^ould like to hclpj please v/rite to:- 



B. S.B.I, Distribution liaps Scheme, 



Botany School, 



Dovming Street, 



University of Cambridge, 

 sending lists or jjidicating what infommtion you hope to be able to contribute. An 

 attempt is being made to vnrite individually to all Vice-County recorders and others 

 actively at work on a local Flora. If you are engaged on such work, and Imve not 

 already heard from us, we should like to have your suggestions as to ways in vrfiich you 

 might co-operate. All help v/ill be acknowledged and v/e \nl.l gladly give more detailed 

 advice on any suggestions you may have, 



A more detailed account of the Scheme is being prepared for the Proceedings, and 

 \TilI appear in the next issue. 



