296 MINNESOTA BOTANICAL STUDIES 



with the meadow formation rather than with the marsh series as 

 proposed in the Phytogeography of Nebraska. 



THE FERN' MEADOW ASSOCIATION 



Still another modification of the typical wet meadow conditions 

 which regularly lie between marshes and meadows is the fern 

 meadow. This widespread and oddly constructed type is a proper 

 subdivision of the meadow formation with a distinct hydrophilous 

 inclination as possessed also by the water hemlock association. 

 With the work that has been done upon these two associations it is 

 impossible to say which is the more mesophytic and which the more 

 hydrophytic. The fern meadows are seen in maximum expression 

 in the lake regions of Cherry County but have also been noted in 

 less noticeable degree in other meadow and lake centers and as local 

 patches along all of the streams of the sandhills. 



Composition of the Fern Meadow Association 



DOMINANT species 



Dryoptcris thelypteris Onoclea sensibilis 



associated species 



Calamagrostis neglecta Mentha canadensis 



Campamila aparinoides Naumbergia thyrsiUora 



Galium trifidum Stachys palustris 



Galium triHorum Teucriiim occidentale 

 Lotus americanus 



The two ferns are absolutely controlling. Dryopteris especially 

 is often seen in such density as not only to exclude all other plants 

 but to produce a ground cover about a half yard in height that is so 

 tangled that walking is difficult over such areas. However, it is 

 more commonly the case that the ferns are sufficiently open to admit 

 of a number of secondary species such as the two Galiums noted 

 above and the galium-like Campanula aparinoides. These harsh, 

 sprawling, clinging stems tangled with the ferns produce a very 

 troublesome cover. 



The association usually occupies rich loamy soil and, in regions 

 where cattle run over the wet meadows during times of high water- 

 content of the soil, is broken up into innumerable hummocks with 

 intermediate depressions about eighteen inches in depth which some- 



