4 Rhodora [January 



2 mm. long, about twice as long us in our other species. The first 

 of these, P. maritima, is a plant of the Atlantic coasts of Europe and 

 of eastern America (from Cape Breton to Pennsylvania); the second 

 an Arctic species which extends southward to Labrador and the 

 shores of Hudson Bay. 



The remaining species have conspicuously smaller anthers, ().."> I 

 mm. long, in only one species very slightly exceeding this measurement. 

 In some of the plants with small anthers the mature caryopsis (and in 

 good specimens of Puccinellia sonic inflorescences are usually mature 

 while others are just expanding) is large, ordinarily more than '2 nun. 

 long, while in others the grains are about L.5 mm. in length. The 

 measurements of the mature grain, like the measurements of the 

 anthers, prove to be essentially constant in all material which is other- 

 wise consistent and we have consequently used this character as an 

 important one. Another character of as great importance is found in 

 the margin of the lemma; in some species the lemma is entire or with 

 at most one or two coarse teeth, while in others it is as definitely erose- 

 ciliolate or serrulate. Good characters are also found in the palea, 

 especially in the degree of ciliation; and other characters, often less 

 readily described and more subject to variation, in the aspect of 

 the panicle, the smoothness or hispidity of the rhachis and panicle- 

 branches, the length of the glumes, etc. 



The present paper, presenting our conclusions regarding the species 

 of PuccineUia in northeastern North America obviously does not cover 

 all the species which may possibly be found in the area. This will be 

 apparent from the fact that one Arctic species alone, /'. pkryganodes, 

 has yet been found on the little-explored Labrador Peninsula, but 

 that in Greenland and Arctic America several other distinct species are 

 found, P. angustata (R. Br.) Rand & Redheld, P. arctica (Hook), 1 

 /'. VaJdiana (Liebm.) Scribn. & Merrill, etc., any of which may be 

 expected to reach the Labrador Peninsula or Newfoundland. Further- 

 more, such very limited collecting as has been done at remote points 

 about the Gulf of St. Lawrence and the eastern coast of Newfoundland 

 has brought together five very distinct plants which are unknown 

 elsewhere in the Last, and future exploration of the complex flora of 

 these areas will doubtless extend the ranges of these plants and pos- 

 sibly bring to light other localized species. 



•Puccinellia arctica (Hook.), n. comb. Glycerin arrtira Hook. PI, Bor.-Am. ii. 

 248, t. 229 (1840). 



