FLORA OF WATER-MEADOWS. 468 
tris, Cardamine pratensis, Cerastium triviale, Lychnis Flos-cuculi, 
Geum rivale, Galium palustre, Senecio aquaticus, Rumex Acetosa, 
Juncus acutifforus, and Eleocharis palustris; whilst Lysimachia 
Nummularia is a conspicuous feature of the aftermath herbage. 
Less prominent, but very noticeable, are Valeriana officinalis, 
Chrysanthemum Leucanthemum, Carduus palustris, Achillea Mille- 
folium, Myosotis palustris, Plantago lanceolata, Ajuga reptans, 
Prunella vulgaris, and Rumex crispus. Of the 20 species here 
enumerated, there are, however, only half a dozen which also 
occur on the dry meadows at Rothamsted, namely, the species 
mentioned of Cerastium, Achillea, Plantago, Ajuga, Prunella, 
and Rumex Acetosa. 
The special characters of the water-meadow flora may be still 
further illustrated by an enumeration of those miscellaneous 
species which occur on the dry meadows at Rothamsted and also 
on land adjoining the water-meadows, but not on these latter 
themselves. These, obviously, are species which are kept off the 
water-meadows as an effect of the periodical flooding of the latter, 
as there can be no adverse influence of soil or situation. They 
comprise :— 
Ranunculus repens, Z. Galium Aparine, L. 
— Ficaria, L. Scabiosa arvensis, L. 
Stellaria Holostea, L. Centaurea nigra, L. 
Agrimonia Eupatoria, L. Carduus arvensis, Robs. 
Anthriscus sylvestris, Hoffm. Tragopogon pratensis, L. 
Daucus Carota, L. Hieracium Pilosella, L. 
Galium verum, Z. Luzula campestris, DC. 
lt deserves to be noted that of the 112 counties and vice- 
counties into which Britain has been divided by Watson, two of 
the water-meadow species— Epilobium tetragonum (33 counties) 
and Rumex aquaticus (37)—occur in less than one third of them ; 
whilst five other species— Thalictrum flavum (65), Lysimachia Num- 
mularia (67), Valeriana dioica (69), Scrophularia aquatica (70), 
and Carex paludosa (70)—are recorded for less than two thirds. 
All the species enumerated as occurring upon the water- 
meadows have therefore been identified upon grass-lands which, 
as stated at the outset, are subjected to the intermittent influ- 
ence of running-water. No notice has been taken of adjoining 
marsh-lands, which are under the influence of stagnant water; on 
these, indeed, some of the species already noted are absent, whilst 
others, such as species of Pedicularis, Anagallis, Mentha, Orchis, 
» are present. 
