Floras of Great Britain and Central Europe. 253 
since it is likely that the dominant species, with the exception of a 
few west European ones, would he the same. 
The transformation of associations, the production of “carr” 
(fen wood) up to the point at which Fraxinus and Quercus enter 
the association of bushes and trees, is still going on before our eyes, 
and is strikingly characteristic of the Norfolk Broads area. 
In connexion with the remark in “Types” (p.235): “The 
establishment of Sphagneta and the presence of moor associations 
on the fen suggest tha<t the fen association may pass into the moor- 
formation,” 1 may remark on the possibility that many great 
“ Hochmoor ” regions, such as for instance that near Konigsberg 
on the coast of East Prussia may similarly be derived from “ fen.” 
We also had the opportunity of studying many interesting 
water plants, partly in communities, partly as species, and not least 
the famous Eriocaulon septangulare in Galway, one of its seven Irish 
stations, “ ranging up the whole west coast, but avoiding the lime¬ 
stone tracts.” 1 So much has been said about the remarkable 
occurrence of this North American plant that I will confine myself 
to one remark. The circumstance has perhaps been too much 
overlooked that several commoner or rarer species which do not 
belong to the circumpolar boreal floristic element, occur in both 
North America and West Europe, though Eriocaulon is the only 
one whose European distribution is confined to Ireland. Thus 
Lobelia Dortmauna, which ranges as far as the Liineburger Heide 
as a rarity, is distributed in the swamps of New England up to 
North Pennsylvania, and from Lake Superior northwards into 
Canada ; while an allied species, L. paludosa, ranges from Delaware 
to Florida and Louisiana. L. Dortmauna is thus the species suited 
to a cooler climate : it strikingly avoids southern England and 
extends from South Wales through Cumberland to the Shetland 
Islands. Ligusticum ( Haloscias) scoticum has a similar distribution. 
In the New World it is distributed from the Behring Sea to Canada 
and Labrador : in the British Isles it occurs in five counties of the 
north coast of Ireland, from which it extends to northern England 
and Scotland. Of water plants Subularia aquatica occurs in North 
America (Yellowstone, etc. in the west, Maine and New Hampshire 
in the east), and also Isuardia palustris and Lysimachia thyrsiflora : 
of bog-moss plants Drosera intermedia. There are in fact a number 
of plants with interesting distributions of this sort which on 
this side of the Atlantic we mostly call west European, without 
mentioning their connexion with North America. 
1 Praeger, “ Irish Topographical Botany,” p. 330. 
