16 BOTANICAL GAZETTE [JANUARY 
Most prominent is the association of about eight herbs which is 
so characteristic of the northeastern conifer forest, and in part of 
similat forests over a much wider range. The group includes the 
following: Cornus canadensis L. (bunch-berry), Trientalis americana 
(Pers.) Pursh (star-flower), Linnaea borealis L. var. americana 
(Forbes) Rehder (twin-flower), Maianthemum canadense Dest. 
(two-leaved Solomon’s seal), Clintonia borealis (Ait.) Raf., Miiella 
nuda L. (mitrewort), Aralia nudicaulis L. (wild sarsaparilla), 
Coptis trifolia (L.) Salisb. (goldthread). These species are found 
in every part of the Isle Royale climax forest, and many of them 
in the bog forest, bogs, and along the rock shores as well. Others, 
less characteristic and abundant, still occur commonly:  Lyco- 
podium annotinum L. (stiff club moss), L. obscurum L. (ground pine), 
Phegopteris Dryopteris (L.) Fée (oak fern), Aspidium spinulosum 
(O. F. Miiller) Sw. (shield fern), Polypodium vulgare L. (polypod), - 
Cystopteris fragilis (L.) Bernh. (fragile fern), Moneses uniflora (L.) 
Gray (one-flowered Pyrola), Ribes prostratum L’Her (fetid currant), 
Epipactis repens (L.) Crantz var. ophioides (Fernald) A. A. Eaton 
(rattlesnake plantain), Oxalis Acetosella L. (wood sorrel), Habenaria 
obtusata (Pursh) Richards, Comandra livida Richards. 
By far the most important part of the herbaceous vegetation, 
both quantitatively and ecologically, is the moss contingent. This 
forms a nearly continuous carpet, being absent only where the 
shade is very dense. Three species are chiefly concerned, and these 
are quite equally distributed, one usually being dominant in a 
given spot. Calliergon Schreberi (Willd.) Grout (Hypnum Schreberi 
Willd.) is perhaps the most abundant, and grows in the drier 
places alone, as well as mixed with the other two in general. Hylo- 
comium proliferum (L.) Lindb. usually covers the areas of well 
decomposed humus; while Hypnum crista-castrensis L. seems to 
prefer rotten wood. Next to these in abundance is Hylocomium 
triquetrum (L.) Lindb. 
The humus soil, which is composed largely of moss remains, 
tree waste, and rotten wood, varies in depth from 0.25 to 6 dm., 
the average being perhaps about 3 dm. It rests directly upon the 
smooth rock surface or is separated from it by a loose layer of 
decomposed fragments. 
