-76- 



This species is the one most easily recognized by beginners, thanks to its large 

 size and usually very squarrose branch-leaves, and should in fact if normally 

 developed be confused with no other. Its other characters have already been 

 sufficiently dwelt upon. An interesting fact long since noted^ is that correspond- 

 ing to its robustness the cortex of the branches usually includes a second layer 

 of empty cells (complete or partially developed). In contrast to the last species 

 5. squarrosum is generally monoicous and fruits commonly and abundantly. 

 Its distribution is essentially that of S. teres, but it is decidedly more common 

 in the southern part of its range. Its present southern limit crosses the states: 

 New Jersey, Pennsylvania, Ohio, Michigan, Wisconsin, Minnesota, Colorado^ 

 California. 



As to phylogenetic relationship there remains not much to be said. Our 

 results could be represented thus: 



Squarosa 



S. Angstromii 



S. squarrosum 



With reference to Malacosphagnum Dr. J. H. Barnhart has called my at^ 

 tention to the fact that S. strictum Sullivant should be dated a year earlier, as 

 Sullivant's collection of exsiccati (with descriptions of new species) was published 

 the year before the appearance of the pamphlet with descriptions, i. e. in 1845.^ 

 It may also be of interest to note a collection of this species in Norway earlier 

 than previously reported. Reference by Dusen^ to a specimen collected by 

 Wulfsberg (in 1874) on the island of Halseno ofif the western coast of Norway 

 and named by him S. squarrosulum which Dusen asserted was S. compactum led 

 me to suspect S. strictum. Herr Kaalaas has very kindly looked up the speci- 

 men in the herbarium of Kristiania University, confirming my suspicion. A 

 portion of the specimen sent me shows characteristic fruiting specimens of 

 strictum Sullivant. 



Ithaca, N. Y. 



1 Cf. already Schimper, Mem. Sphaign. and Vers. Torfm., pi. XVII, fig. 12. 1857, iSsS. 



2 Cf. Amer. Journ. Sci. and Arts, 2d Series, I, 70. 1846. 

 ' Om Sphagnaceernas Utbredning 79. 1887. 



