442 



BOTANICAL GAZETTE 



[DECEMBER 



one-tenth of an acre (fig. 10). On the south, west, and north sides 

 it is bordered by clay hills which rise 25 to 40 feet (7.5-i2 m ) above 

 the bog level. The vegetation of the hills is dominated by Quercus 

 velutina, Q. alba, and Q. rubra. With these trees occur Hicoria 

 ovata, Hamamelis virginiana, etc. 



On the north side the upland has been cleared, and the land is 



now under cultiva- 

 tion. From time to 

 time tamaracks have 

 been removed from 

 the bog, until at the 

 present time only the 

 central area remains 

 to indicate the origi- 

 nal covering. Accom- 

 panying the clearing 

 there has grown up 

 about the tamaracks 

 the usual thicket of 

 shrubs and young 



trees. As elsewhere, the peat is more thoroughly decayed and the 

 substratum level somewhat lower about the margin than toward the 

 center. This fact is of importance in differentiating the willow-sedge 

 society. 



Tamarack society. This society is dominated by the group of 

 rather mature tamaracks. The substratum has the characteristic 

 hummocky surface, marked by large exposed roots, common to such 

 areas. It is overlaid by a loose covering of vegetable matter, made 

 up principally of tamarack needles. The undergrowth is sparse, 

 but most of the bog shrubs and herbs are represented. The more 

 important species are Chamaedaphne calyculata, Sphagnum cymbi- 

 folium, S. recurvum, S. subsecundum, Eriophorum virginianum, 

 and Lycopus virginicus. A very noticeable growth about the bases 

 of most of the shrubs is produced by the fungus, Thelephora inty- 

 bacea. The mycelium in developing its sporophores rises about 

 the stems, frequently to a height of a foot (25 cm ). From the cylinder 

 thus formed, irregular fan- shaped pilei are developed, which gives 



FIG. 10. Bog on Carpenter road. 



