

44 BOTANICAL GAZETTE [January 



\ 



than the one observed by Cooper (4) in regard to the balsam on 

 Isle Royale. These two maples are ecologically of the sapling type; 

 that is, they reach their highest development in a form ecologically 

 equal to the second life age of the sugar maple. Beyond maturity 

 they have such a high death rate that, although often as abundant 

 as sugar maple at the sapling age, they are rarely represented in 

 the third age. Gleason's (ii) significant tabulation shows Acer 

 pennsylvanicum as the dominant tree after clearing. The con- 

 trary occurrence from that of the maple is observed in the case of 

 the hemlock, very few seedlings of which are seen in the climax 

 forest, although a fair number of the adults are constantly present; 

 for, because of scattered occurrence of young trees, it is not probable 

 that the species is dying out. 



Shrubs are not common through the climax forest. Cornus 

 alternifolia L. f. is often seen in the Bay View woods. The char- 

 acteristic shrubs of the region include Sambucus racemosa L., 

 Ribes Cynosbati L. (transitions to R. gracile Michx. seem to occur), 

 R. lacustre Pon\ (along Little Traverse Bay), Lonicera (L. hir- 

 suta Eaton is occasional along Little Traverse Bay), Taxus cam- . 

 densis Marsh, Rubus Idaeus L., R. allegheniensis Porter, and Aralia 

 racemosa L. The last is really an herb, but it is so tall and large 

 that it is ecologically a shrub and occupies the shrub stratum. 



The herbage of the climax forest is varied and fairly abundant. 

 The prevernal flora is sun-loving and close, forming continuous 

 masses of foliage composed of few species and many individuals. 

 In the upland woods the dominant species is Dicentra canadensis 

 Walp., but in the woods along Little Traverse Bay Dentaria diphylla 

 Michx. appears more prominent. Transition forms to the summer 



flora occur; for example, Caulophyllum thalictroides Michx. is 

 prevernal in leafing and flowering, while in fruit it is strictly aestival. 

 Allium tricoccum Ait. also has prevernal leaves which die down 

 before the scape appears in early summer. 



The summer herbage is more scattered and richer in species, its 

 richness varying with the age of the youngest tree generation. It 

 is shade tolerant, and characterized by about 50 species. Particu- 

 larly characteristic among them are Botrychium virginianum Sw., 

 Aspidium spinulosum Sw., Trillium grandijlorum Salisb., Maianthe- 





