2 



that part which lies above the middle of the achenium being 

 Spongy, thickened and plump; in mature specimens the lower 

 portion, by compression against the achenium, being thin and 

 showing three, or sometimes only one, nerve. In immature speci- 

 mens the scales are not thick and plump above but of nearly the 



m 



same leathery texture throughout, the nerves traceable to the 



apex. The middle nerve may end in a mere apiculation, in 



some cases wanting, or may be produced into a short blunt point 

 or long barbed awn. And in some cases this awn may arise on 

 the back of the scale slightly below the apex. 



While making an examination of the forms that have been 

 grouped under F. squarrosa It seemed desirable to include as well 

 our other entirely distinct species, F, scirpoidca ; and as a result 

 the following revision of the species of Fiiirena of the United 

 States is presented. 



The localities given after each species and variety were taken 

 (except in one case which is indicated) from actual specimens 

 examined by the writer. These were in the herbaria of Colum- 



L 



bia College, Harvard University, Cornell University, Academy 

 of Natural Sciences of Philadelphia, William M. Canby, Isaac 

 C. Martindale, John Donnell Smith, and the National Herbarium ; 

 and thanks are due to these three gentlemen, to Dr. Sercno 



Watson, Dr. N. L. Britton, Prof. William R. Dudley and John 

 H. Redfield, for their kindness in facilitating the work. 



To Dr. Britton I am especially indebted for notes from Mr. 

 C. B. Clarke of Kew, and for many valuable suggestions. The 

 specimens in the Shaw herbarium were examined, but by an 

 oversight the localities are not included. 



FUIRENA. 



Rottboell, Descr. et Icon. PL p. 70 (1773). 



h 



Inflorescence in terminal and axillary heads of spikelets, the 

 axillary ones sometimes wanting, and the terminal one reduced 

 even to a single spikelet. Spikelets many-flowered. Glumes 

 imbricated on all sides, aristate or mucronate, the lowest one or 

 two empty. Flowers hermaphrodite. Perianth-scales three, not 

 conduplicate, commonly stipitate, membranaceous or thickened, 

 in the American species with as many bristles alternating. Sta- 

 mens three. Style single, slender, not thickened at the base nor 



/j> 



