. 432 BOTANICAL GAZETTE [MAY 
tuber-bearing rhizomes of Eguisetum arvense. In drier situations 
the bulbs of Lilium canadense occur at a similar depth (most often 
about 10 cm. deep). Higher in the soil may be found (fig. g) roots 
of such species as Asclepias incarnata, Thalictrum revolutum, and 
Lathyrus palustris, while the surface soil contains a mixture of the 
root systems of Poa pratensis, Agrostis alba, Eleocharis palustris, 
Acalypha virginica, etc. In the community shown in fig. 9, Equtse- 
tum is edaphically complementary, but (considering only the aerial 
sterile shoots) aerially competitive with Poa, Agrostis, Eleocharis, 
; ae pe 
eS 
Fic. 10.—a, Lycopus americanus; b, Viola conspersa; c, Viola cucullata; d, Iris 
versicolor; July. 
and Acalypha. To a moderate extent, the plants rooting near or 
at the surface cee to be complementary with the plants rooting 
deeper. 
Small, apparently open depressions are numerous in the moist 
parts of the meadow. These generally contain (fig. 10) such plants 
as Iris, Acorus, Viola conspersa, V. cucullata, Cardamine bulbosa, 
and seedlings of Lycopus americanus. And while the rhizomes of 
Cardamine. and Lycopus occur almost invariably just below those 
of the other species, and while the different species doubtless make 
