60 ECOLOGICAL RELATIONS OF THE FLORA. 



by the distribution of Pinus strohus as given by Sargent and (in 

 Michigan) by Spalding (1899). The range of this tree is not restricted 

 to the St. La^\Tence basin but extends from New Brunswick along the 

 ocean well through the Atlantic states, following the Allegheny Moun- 

 tains almost to North Carolina. The explanation of this range seems 

 to be found largely in the climatic conditions. 



Engler points out that there is a difference in the secondar}^ species 

 found in the Atlantic States and those found in the_ St. LawTence Basin, 

 and he denotes the Atlantic States portion of the Pinus strobus province 

 as the transition zone between this province and the ^Mississippi and 

 Allegheny Forest Province. (Engler, 1902.) The forms and species 

 enumerated for this last proAdnce he records as having penetrated to 

 Nova Scotia, New Brunswick and Ontario, and we find them in Mich- 

 igan. A comparison of lists shows that the typical species of each zone 

 are present at Sand Point. 



It is interesting to note that the plants of the Mississippi and 

 Allegheny Province are almost altogether confined to the swamps or 

 thicket formations while those of the Pinus strohus zone proper are 

 on the sandy ridges. This affords an hypothesis to account for the 

 difference in the secondary species of Sargent's White Pine Forest 

 Area, for apparently the climatic factors account for the wide distribu- 

 tion of the pine but the edaphic conditions determine the exact makeup 

 of the formations. The sandy ridges are taken by the hardier, less 

 mesophytic northern societies and the loamy portions support the 

 flora ^vhich we have learned to associate with the deciduous woods. 

 Hence the leached glacial till of the St. LawTence and Great Lakes 

 is held by pines with the somewhat scanty accompanying flora, and the 

 levelled highlands of the coast states with its richer soil is taken by the 

 mesophytic species from the Allegheny-Mississippi zone. 



GENERAL SUMMARY. 



The Sand Point successions fall into two ts^pes: The swamp series 

 (lagoon-swamp-thicket-forest) and the sand series (beach-heath- 

 jack pine barren). The progression is to a similar mesophytic forma- 

 tion in each ca.se.* 



The following fungi were noted for the firf-t time in the state ; 

 Clitocybe laccata Scop 

 Clitociihe pinophila Pk. 

 Clitocybe ochropiirpurea Berk. 

 Fuligo ovata Schaeff. 

 Hypocrea Richnrdsoni Berk. & Mont. 

 Hypoxylon nnnulatum (Sch.) Mont. 

 Hypoxylon atropurpureum Fr. 

 H ejniirichia clarata (Pers.) Rost. 

 Nummularia Bullardi Tul. 

 Paniis rudis Fr. 

 Porta vaporia Fr. 



Russula emetica' Fr. (Swamp Form.) 

 Russula relernosa Fr. media. 

 Stemonitis Smithii yia.cb. (S. femiginea Ehren.) 



