196 BOTANICAL GAZETTE [MARCH 
Carex filiformis L., C. limosa L., C. chordorrhiza L. f., C. poly 
Schkuhr, C. ldiastersa Micix.. and C. livida (Wahlenb.) Willd 
Along the outer edge of the mat and almost forming a zone by 
itself is a fringe of Menyanthes, its thick rootstocks closely inter- 
twined. The shrub zone, dominantly Myrica Gale L. (sweet gale), 
is poorly developed, and sphagnum is nearly absent, only a sparse 
growth being seen and this nearly choked by the luxuriant sedges. 
Along much of the southeast shore the sedge mat is absent and 
the shrubs are the marginal vegetation. Here Chamaedaphne and 
Fic. 34.—Pond near Tobin’s Harbor in Sec. 5, T. 66 N., R. 33 W.: aquatics 
occupying center; sedge zone of Carex filiformis ay in the background hoary 
alder and tamaracks bordering the climax forest. 
Andromeda grow actually in the water. Davis (19) has noted this 
replacement of the sedge zone by a shrub mat as a very common 
occurrence in the bogs of the northern peninsula of Michigan, but 
it is rare on Isle Royale. The bog forest at Sucker Lake is a mere 
line of tamaracks along the sides of the basin, but is well developed 
at both ends, where great stretches of the narrow depression have 
been converted into a forested valley. Sucker Lake is the last 
remnant of a body of water that was once very similar to the Rock 
Harbor of today. 
