-8- 



ieaf , a fact apparently explaining the origin of the synonyms S. de- 

 generans Warnst. and 5. iurfaceum Warnst. already mentioned. It 

 should be said at the same time that specimens of 5. palustre from our 

 Pacific coast tend to have chlorophyll cells with a broad base, possi- 

 ble of confusion with S. imbricatum var. affine if one examine with 

 reference to this character alone and that without sectioning the leaf. 

 Both the section and the other characters place them with 5. palustre. 

 If the branch leaves of these Pacific coast specimens are examined 

 on the inner surface the areolation is peculiar in that the chlorophyll 

 cells, while very wide in their central part, are narrow at their ends, 

 quite corresponding with Warnstorf's figure^'^ of 5. pseudocymbifolium 

 C. M. from the Himalayas of -Asia. That this last is specifically dis- 

 tinct from 5. palustre is, however, questionable in the extreme. 



Anyone collecting Sphagna in the United States or British America 

 is sure to get 5. palustre and will want directions for avoiding it rather 

 than the contrary. I can, however, give none. So far as distinction 

 is possible in the field one should learn to distinguish the others of 

 the subgenus and assume that all specimens not strongly characteris- 

 tic belong to 5. palustre unless one is collecting in a locality of special 

 interest or is otherwise enabled to collect everything. Its colors are 

 green to brown, it generally grows compactly, may be robust, and 

 fruits rather frequently. 



4. SDhagnum henryense Warnstorf 1900. This species was discov- 

 ered by Kearney in the region of Cape Henry, Virginia, from which 

 place it takes its name.^~^ Its specific value was recognized and well 

 diagnosed by Warnstorf^^^ The chlorophyll cells of its branch 

 leaves have in section the shape and position of those of 5. palustre^ 

 nor is there much in its external appearance to separate it from that 

 plant. Its chief peculiarity is the condition of the inner walls of the 

 hyaline leaf cells where they overlie the chlorophyll cells, their sur- 

 face being roughened by a very fine-meshed network of prominent 

 ridges, especially in the lower rart of leaf. The fact that this sur- 

 face is roughened will be noted on microscopic examination of inner 

 leaf surface, also of transverse section of branch leaf, but its exact 

 nature can only be made out, as Warnstorf emphasizes, by longi- 

 tudinal leaf sections, best secured by sectioning longitudinally one of 

 the short branches of the capitulum. It will then be found to be en- 

 tirely different from the papillae of 5. papillosum and more closely 

 resembling the condition of S. imbricatum, differing, however, in the 

 fact that the ridges are not nearly so high, so that they do not give 

 the fringe- fibril effect of that species, and that they form a network 



(1) Hedwigia 3«: pi. xx.fig. g. 1891. 



(2) Cf. Contributions U. S. Natl. Herb. 5: no. 6, 510. 1901. 



(3) Hedwigia 39: 107. 1900. 



