78 Rhodora [April 



Mountain Lake, Franklin County (.1. Lorenz). New Hampshire: 

 Eagle Lake, Mt. Lafayette {('. ('. Haynes, A. Lorenz A- A. II'. E.). 

 Vermont: Bloodsueker Pond, Jamaica (F. Dobbin); Willoughby (.1. 

 Lorenz & A. W. /*'.); Franklin and Burke (.1. Lorenz). Connecticut: 

 Bethany (.1. IF. E.), cited by Muller; specimens from the same local- 

 ity (F. Bement) but incorrectly labeled "Lebanon" were distributed 

 in Hep. Amer. 190, as N. irrigua; Norfolk and New Fairfield ((?. E. 

 Nichols); Bailey's Pond, Voluntown (.1. W. E.). The following 

 stations outside New England may likewise be recorded: St. Ann's 

 Mountain, Cape Breton, Nova Scotia (G. E. Nichols 218)", Campo- 

 hello, New Brunswick (IF. G. Farlow); St. Hubert, Quebec (Brother 

 Victoria); near Ottawa, Ontario (J. Macoun I); Port Clarence, 

 Alaska (IF. //. Brewer & IF. R. Coe 673), cited by Muller; Podunk 

 Marsh, West Fort Ann, New York (S, //. Burnhum); near Superior, 

 Wisconsin (G. //. ConJdin 1009, 1258). 



In describing S. palvdicoia as a " kleine Art," Muller calls attention 

 to the strong superficial resemblance which it bears to S. paludosa K. 

 Mull. In his opinion, however, the two species arc not as closely 

 related as might be supposed; he considers that S. paludosa has been 

 derived from S. undulata, while S. palvdicoia has been derived from 

 S. irrigua. In S. undulata and S. paludosa he finds that the leaf-cells 

 are either thin-walled throughout or develop uniformly thickened walls 

 (in which trigones are usually absent altogether), while in S. irrigua 

 and S. palvdicoia, trigones are invariably present and may be very 

 conspicuous. Apparently S. palvdicoia is not uncommon in northern 

 North America, having been confused with S. irrigua. In fact several 

 of the stations cited above have already been reported under the older 

 species. Muller brings out the fact that S. paludicola prefers calcare- 

 ous bogs, without being confined to them, and this preference is 

 apparent from its North American stations. 



The occurrence of 8. paludicola in bogs, its robust habit, its deeply 

 divided leaves, its short and arched keel usually without alar out- 

 growths of any sort, its deeply cordate dorsal lobes directed toward 

 the apex of the stem rather than obliquely outward, and the trigones 

 in its leaf-cells will usually make its recognition an easy matter. The 

 margins of the leaves may be sparingly and minutely toothed or sub- 

 entire and both lobes are often distinctly apiculate. The short and 

 strongly arched keel and the cordate dorsal lobe directed forward will 

 distinguish the species at once from both S. irrigua and S. undulata, 

 while the trigones will readily separate it from S. palvdosa. 



