VASCULAR PLANTS COMMON TO THE ARCTIC AND 

 THE BRITISH ISLES : ENUMERATION OF SPECIES 



Nicholas Polunin 



Harvard and Yale Universities, U.S.A. 



The availability of (a) a ' working ' delimitation of the Arctic (Polunin 1951), (b) a 

 manuscript ' Circumpolar arctic flora ' in which I have treated all of the recognized 

 species of vascular plants known to reach the prescribed area, and (c) a modem British 

 flora (Clapham, Tutin and Warburg, 1952, hereafter referred to as ' F.B.I.'), has 

 made it desirable, with much further exploration in the Arctic and botanical discover\- 

 in the British Isles (cf. Lousley 1951, 1952; Polunin 1953), to undertake a more adequate 

 treatment than was formerly available (Polunin 1939a, 1939b) of the subject of ' arctic 

 plants in the British Isles.' The bases and results in outline of this revised anah'sis of the 

 vascular plant species common to the Arctic and the British Isles have recently been 

 published (Polunin 1954), and it now seems desirable, as on the former occasion before 

 the war, to offer also details of the plants concerned in the various ecological (or some- 

 times phytogeographical) categories. 



In the lists given below the order is that of F.B.I. , as are in general the ortho- 

 graphy and nomenclature. Where the nomenclature differs from that used in F.B.I. , 

 or where this last supplants some more familiar designation, sufficient synon>Tiiy is given 

 to orientate the reader : this is especially necessar^^ with some widely inclusive species 

 (indicated by " s.l.") which have been maintained here for reasons either of taxonomic 

 preference or personal uncertainty (e.g. w^here insufflcient material has been available 

 for demonstration of conspecificity or for satisfactory appraisal of the situation in the British 

 Isles and the Arctic together). This has allowed the inclusion in some instances of different 

 subspecies, admittedly with probably different ecological relationships, as representatives 

 of a species in the north and south ; but there are doubtless more segregations and discoveries 

 to come. There were also occasional needs for changes (usually indicated by citing 

 authorities) in accordance with the International code of botanical nomenclature as recognised 

 in my ' Circumpolar arctic flora ' or otherwise in relation thereto, though in general where 

 matters of mere personal preference were concerned I ha\'e given precedence in the present 

 lists to the F.B.I. and mereh indicated by adding synom-ms that other opinions exist. 



Worse difficulties ha\-e been encountered in the assignment of some species to their 

 proper ecological, etc., category ; and indeed the categories, like all too many biological 

 entities, are somewhat nebulous and apt to overlap. When the entire picture is considered 

 as a whole, however, these components stand out with fair clarity, and it is certainly 

 hoped that anyone interested in the subject will supplant the old analysis with this new one 

 which is much more worthily based. Especially has it a far less restricted and more 

 logical and scientific ' Arctic ' as its basis. 



A single asterisk before the name of a plant indicates that it is, supposedly, introduced 

 in the Arctic, and a double asterisk at the end of a plant's treatment indicates that it appears 

 to be introduced in the British Isles : a few species are both. Introduced plants are taken 

 as those of which the ancestral disseminules were supposedly transported by man to the 

 region concerned, whether in ancient or modern times, so long as they appear to be 

 established and able to persist from generation to generation without his continued inter- 

 vention. When an otherwise introduced species appears to be native in any place in a 



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