190 



better soils, because the latter is less tolerant of shade. The fol- 

 lowing list shows the relative degree of tolerance beginning with 

 those that require the most light : Larix americana, Popuiiis 

 trcniii/oidcs, Pniuiis pcnnsylvanica, Pimis St7'obus, Bettda lutca, 

 Acer nibnivi^ Abies bahauiea, Picea Mariana {= P- riibens Sar- 

 gent), Tsuga canadensis, Fagus anicricana and Acer saceharnvi, 

 while the best soils support Fagns amcricana. Acer saccJiarnvi 

 and species in general ma}- be arranged according to edaphic re- 

 quirements, beginning with the most requiring : Prunns serotina, 

 Acer saccliariiui, Fagus aviericaiia, Acer rnbrnni, Pinus Strobns, 

 Abies balsamca and Picca Mariana { ^ P. nibens Sargent). 



As one ascends, the facies in some places consists of the de- 

 ciduous species mentioned with such ferns and herbs on the 

 ground as AdiaiUnni pedatuvi, PolysticJiuni acrosticJioides, Mono- 

 tropa uniflora, Chiogenes /dspid?da, Clintonia borealis, Corniis 

 canadensis and Pajiicularia elongata. At 3,600 feet, especially 

 on the southern flanks of Mt. Tahawus, the forest formation con- 

 sists of Picea Mariana (red spruce = P. rnbens Sargent), Betula 

 lenta, Betula lutea, Sorbus anui-ieana, Abies balsamca and Tliuja 

 occidentalis ; and Veratrnni viride occurs on the forest floor with 

 Vacciniiun canadense, Lycopodiuni annotinnni, L. luciduluni, Aster 

 acuminatus, Solidagojlexicaulis, Coptis trifolia, Linnaea amcricana 

 and Strepfopus aniplexifolius. Solidago flexicaulis may be the 

 lowland representative of the alpine Solidago alpcstris. 



CoMFEKOUS FoKMATiox. — Thcsc southem slopes are the 

 spruce slopes, according to the designation of the lumbermen, 

 because Picea Mariana (= P. rubens Sargent) is dominant. The 

 absence o( Acer sacc/iarum, Acer rubrum and Viburnum alnifolium 

 is due to elevation and is noteworthy. Abies balsamca on an 

 elevated saddle of the mountain forms a pure forest with shrubby 

 and herbaceous companions {^^Ibies facies), and in open swampy 

 places surrounded by the balsam occur Osmunda cinnamomea 

 and Veratrnm vindc. 



The " Kruinm-holz," or dwarf timber, is reached at 5,000 feet 

 ( 1 ,5 50 m.) on Mt. Tahawus (Mt. Marcy). Here Abies balsamca is 

 about five feet high, with its base covered by Hypnum splendens, 

 H. Crista-castrensis and Dicranum sj)., with Linnaea amcricana, 



