MICHIGAN ACADEMY OF SCIENCE. 
59 
The Iris versicolor Association. 
This composit association was often present around the edges of 
bogs, along the roadsides, along the edges of thickets, and in burnt-over 
land which had not yet become dominated by either shrubs or trees. 
List of the Species of the Iris versicolor Association : 
DOMINANT SPECIES. 
Iris versicolor. Ly copus amerieanus. 
A sp i cl iu m the lypteris. Eupatorium perfo Via t am. 
Eupatori urn purpureum. 
SECONDARY SPECIES. 
Civ si a/m muticum. 
Glycerin borealis. 
Eriophorum viridi-carinatuni. 
Gin na aru ndinacea. 
II yp ericii m virg i nic m n. 
L ysimach iu terrestris. 
A sclep ias incarn cita. 
Lobe Via cardina l is. 
Scutellaria galericulata. 
P ran e l la vulgaris. 
Rub us tr i floras. 
Mini ul us ringens. 
Dui ich him arundinaceum ., 
Polygonum amphibi inn. 
Roripa palustris hispida. 
Campanula aparinoides. 
Rumex crispus. 
RELIC SPECIES. 
Typha latifolia. Potentilla palustris. 
Pot en till a a n s eri na. 
INVADING SPECIES. 
Sambuciis canadensis. Spartinci michauxiana. 
Cor nus stolonifera. Salix lucida. 
Acer rubrum (seedlings). Salix spp. 
Thuja occidentaUs (seedlings). 
The Salix-Cormis Thicket Association. 
Along the borders of some of the cedar bogs, but especially along 
roads thru them, and surmounting the bluff or dune at the limit of ice 
work around Douglas Lake, occurred this thicket association. The soil 
in which it grew was wet, altho in certain cases there was a surface 
layer of nearly dry sand. The association is characterized by the growth 
of willows, of which Salix lucida is the most prominent. This is shown 
in Plate 7b. In good situations this thicket growth may attain the 
proportions of a grove of small trees but usually before that time, 
seedlings < f (lie succeeding association have come in and transformed 
the area into a bog. In drier situations a stand of red pine may succeed 
such a thicket. 
