-63— 



"Museum a special packet enclosed in No. 343 is labeled Acrolejeunea torulosa, the 

 name under which Spruce distributed the species in his exsiccatae. This special 

 packet, in the writer's opinion, likewise contains nothing but Brachiolejeunea 

 ■corticalis. If this determination is accepted there remain no North American 

 records for P. torulosus, and the only member of the genus definitely known 

 from north of Panama is P. polycarpus (Nees) Trevis., recently described and 

 figured by the writer/ 



1 Bull. Torrey Club 35: 162. pi. 7, f. i-n- 1908. 



Yale University 



NOTES ON NORTH AMERICAN SPHAGNUM, HI 



A. LeRoy Andrews 

 The Subgenus Inophloea Russow (concluded) 



The four species previously treated stand out very definitely and may be 

 considered as taxonomically conclusive; the remaining species of the subgenus 

 are much less understood in their relations on the one hand to 5. palustre, on 

 the other to each other, as the extensive synonymy of comparatively recent 

 date will readily show. Their foremost common characteristic is found in the 

 chlorophyll cells of the branch leaves, which with a central lumen are usually 

 equally exposed on both surfaces or on neither; there is rarely a greater or ex- 

 clusive exposure on the inner surface, but the section with the characteristic cen- 

 tral lumen shows where the plant belongs. For the rest there is a notable tend- 

 ency to a reduction of pores in the outer walls of the cortical cells of the stem, 

 in which point as in other minor particulars the remaining species of our group 

 show a somewhat closer relationship to Litophloea. 



5. Sphagnum papillosum Lindberg, 1872. This species is in typical speci- 

 mens recognizable by the papillose inner walls of its hyaline leaf cells, the papil- 

 lae being of course confined to the part of the wall immediately overlying the 

 chlorophyll cells. If one is using high magnification with good light, he will 

 note the papillae on viewing the inner surface of the leaf; they are also in evi- 

 dence in a transverse section, but can be best observed in a longitudinal one. 

 The chlorophyll cells themselves are normally more or less barrel-shaped in 

 section, usually exposed on both surfaces, and have a central elliptical lumen 

 and thick walls. The most essential features of the species were all well brought 

 out by Lindberg in the original short diagnosis.^ Others were noted by Rus- 

 sow the cortical cells of the stem have their fibrils much reduced or almost 

 entirely lacking, the fewer pores (especially often 2) of the outer cortical cells 

 are small, usually round and very clearly defined, as is shown in Braithwaite's 

 plate,^ the stem leaves are relatively broad in comparison to their length and 



1 Contributio ad floram cryptogamam Asiae boreali-orientalis 280. 1872. 

 -Znr Kenntn. d. Subsec. u. Cymbif. Gruppe europ. Torfm. 117 ff. 1894. 

 3 Sphagnaceae of Europe and North America pi. IV, fig. gc. 



