120 FLORA OF THE UPPER SUSQUEHANNA. 



E. acicularis (L.) Roem, S: Schult. Needle-Spike-rush. Very- 

 corn mon on the borders of lakes and streams at the very- 

 edge of the water. Stems usually less than six inches high, 

 often forming thick mats over considerable areas. Bristles three 

 or four, falling early. 



SCIRPUS L. 



S. planifoHus Muhl. Wi^ou Club-rush. Frequent on dry knolls, 

 Lj^cv. Plentiful on dry banks at Apalachin, Fenno. Elsewhere 

 not reported ; probably overlooked. Bristles four to six, barbed 

 upward. The bristle-tipped scale overtopping [the chestnut- 

 brown spikelet. 



S. lacustris L. Great Bull-rush. Common on the borders of 

 lakes and the larger streams, nearly always in shallow water. 

 Stems round and very tall. 



S. atrovirens Muhl. Dark-Green Bull rush. Common about 

 swamps, ditches and in low grounds generally throughout our 

 range. Our earliest Scirpus. 



S. polyphyllus Vahl. Leafy Bull-rush. Not uncommon, 

 Graves. Elsewhere not reported. Spikelets yellow-brown, 

 clustered in threes and eights, division of the umbel short. 

 Bristles six, flexuous. Resembles S. atrovirens. Verified by 

 Prof. Thomas C. Porter. 



S. cyperinus (L.) Kunth. Wool-Grass. Cotton- Grass. Very 

 plentiful in low grounds. ( Eriophorum cyperinum L. ) 



S. cyperinus Eriophorum (Michx.) Britton. Probably more 

 common than the type, from which it is distinguished by its 

 long-pedicelled, lateral spikes. {Eriophorum cyperinum, var. 

 I ax u VI Gray.) 



ERIOPHORUM L. 



E. Virginicum l>. Virginl\ Cotton-Grass. Common in bogs 

 and swamps throughout our range, except in the Chemung val- 

 ley, where it is probably overlooked. Wool rusty, or copper- 

 colored ; spikelets nearly sessile. 



E. polystachyon L. Tall Cotton-Gkass. Frequent. Found 

 in the same situations as the preceding. Culms a foot or more 



