MICHIGAN ACADEMY OF SCIENCE. 
10 
TJ vu laria grandiflora. 
0 si nun da claytonian a. 
Po lygona turn bi/l ovum. 
Gaulophyllum thalictr aides. 
Actaea alba. 
Lactuca spicata. 
Vi o la scabrkiscula . 
Vio la p ap ilio n a cea . 
Mitella nnda. 
Dierri lla lonicera. 
Rub us idaciis aouleatissimus. 
Epilobium. angns tifo l i inn. 
Brig era n can a den sis. 
Aralia hispida. 
* Streptopus am piece i ca i d i s . 
Asplenium jdix-f or inina. 
Solanum nigrum. 
Lactuca spicata integrifolia, 
Geuni sp. 
Aspidium novcboracense. 
Impatiens pallida. 
Erech tiles hieracifolia ( few ) . 
Epilobium angustifolium. (few) . 
Aspidiu m golclianu m . 
SPECIES. 
Pteris aquilina. 
Gaultlieria procumbcns. 
Foci pratensis. 
Ly copus am ericanus. 
Rub us triflorus. 
THE ASSOCIATIONS OF BURNT LAND. 
The Fire-weed Association. 
This association of rapidly growing and maturing annuals is usually 
very quick in making its appearance after nearly any burn. Dur- 
ing 1911, after a severe burn in the cedar bog southeast of Douglas 
Lake, matur fireweeds were found in the burnt area three weeks after 
the fire. The fireweeds prefer a mineral soil, especially the one left 
after a fire, whence their name. In the region the species of plants 
which entered most largely into its composition were Epilobium angusti- 
folium, Erechtites hieracifolia and Erigeron canadensis. . The Epilob- 
ium was by far the most abundant. As an association it is short-lived, 
often existing for not more than a year, altlio individual plants may 
occur as scattered or isolated relics for a number of years. The succeed- 
ing association depends largely upon the severity of the burn and the 
surrounding associations. In general over the greater part of the area 
aspens appear and rapidly change the type of vegetation. This is nearly 
always true on pine land. On hardwood land this is also true in case 
of severe burns which have burnt the humus out of the ground. In 
moderate burns there is sometimes a short fireweed stage followed by 
hardwood directly but more often brambles — especially Rubus idaeus 
aculeatissimus — appear with the fireweeds and with them persist for 
a number of years befor giving place to hardwood. On bog land fire- 
weeds are rarely followed by aspens but usually seedlings of the bog 
trees appear within a year or two and the bog gradually becomes re- 
establisht. 
List of the Species of the Fireweed Association : 
DOMINANT SPECIES. 
Epilobium angustifolium. 
Erech tites hieracifolia. 
Rumex acctosclla. 
E i ' igero 1 1 cat laden s i s . 
