508 PROCEEDINGS OF THE AMERICAN ACADEMY. 



and other caricologists identical with the European ; but in 1866 the 

 New York plant was distinguished by Dewey, on account of its tall 

 slender culm, narrow leaves and loose spikelets as var. alto-caulis. In 

 1889, however, Professor Bailey raised the American plant to specific 

 rank as C- saltuensis, separating it from the European C. vaginata " by 

 its much more slender and less caespitose habit, narrower leaves and 

 less conspicuous sheaths, its alternately-flowered spikes, and its much 

 smaller, less inflated, and conspicuously nerved perigynium." And Dr. 

 Britton, following Professor Bailey's lead in treating the plant as 

 strictly American, has taken up for it Dewey's varietal name as 

 altocaulis (not alto-caulis). 



That American specimens from the deep swamps of western New 

 York, Ontario and Michigan are more slender than some European 

 specimens there can be no doubt; but in northeastern Maine, where the 

 plant is a common species of arbor-vitae swamps, it varies greatly in 

 these characters. Individuals growing in excessive shade are naturally 

 taller and more slender than those in bright light ; and the spikelets 

 vary indiscriminately from the slender alternate-flowered tendency sup- 

 posed to characterize the American plant to the dense-cylindric form 

 said to distinguish the European. 



The height of the European plant, too, is often as great as that of the 

 American, while our own plant sometimes fruits when scarcely 2 dm. 

 high (Mt. Albert, Quebec — Allen ; lilaine, Maine — Fernald). A speci- 

 men from Christiania collected by Blytt is 5 dm. high, while the extreme 

 height given by Dr. Britton for his C. altocaulis is 2 feet (6 dm.). 



The breadth of the leaf, likewise, is as variable on one continent as on 

 the other. Both Dewey and Bailey have maintained that the European 

 plant is broader-leaved ; yet a specimen from Fries collected in Jemtland 

 (Sweden) has leaves from 1.5 to 1.75 mm. wide, while the broadest 

 leaves seen on the European plant are those of a Lapland specimen 

 (5 mm. wide) from N. J. Anderssou. In the American plant the leaves 

 vary from 1.5 mm. wide (Blaine, Maine) to 5 mm. (Montreal). 



The variation in the density of the spikelet in the American plant has 

 been already mentioned. In Europe the same variation occurs, speci- 

 mens from Jemtland (A/(lbe>-g), Lapland (^Andersson) and Finland 

 {Lehmann) having the spikelets as loosely flowered as in the most 

 extreme American form. 



Nor are the differences assigned by Professor Bailey to the perigynia 

 maintained in mature specimens. Young individuals of the American 

 as well as the European plant have the nerves poorly developed, but in 



