126 Rhodora [July 



variety are hardly more than setaceous; up to 40 cm. long, with a 

 diameter of about one millimeter; the sori show a tendency to an 

 arrangement in rings about the frond. Found in a tide pool at Cedar 

 Ledge, Casco Bay, Maine, July 15, 1904. 



Malden, Mass.\chusetts. 



SOME NEW OR LITTLE KNOWN CYPERACEAE OF 

 EASTERN NORTH AMERICA. 



M. L. Fernald. 



Recent studies in various genera of Cyperaceae in the eastern United 

 States and adjacent Canada have made it necessary to recognize a 

 number of undescribed species and varieties in our flora and to alter 

 the current interpretation of some others. These items which have 

 been accumulating for some years are here brought together as a series 

 of notes arranged in the sequence of the genera and species as now 

 understood by the writer. 



Cyperus dentatus Torr. Fl. 61 (1824) was based upon C. parvi- 

 floriis Muhl. Gram. 19 (1817), not Vahl. To the characterization 

 of Muhlenberg's plant with the "Habitat ad ripas Susquehannae. . . . 

 etiam in N. Anglia",^ and with "Spiculis 3 compressis alternis ovatis, 

 8-floris," ^ Torrey added "Spikes. . . .appearing dentate or pectinate 

 by the spreading of the points of the glumes when old"; ^ thus indi- 

 cating very clearly a plant which occurs on sandy shores from central 

 Maine to western New York and southward at least to West Virginia. 

 This characteristic plant with prominent scale-tips varies in the num- 

 ber of flowers from 5 to 13, and the spikelets are very often altered 

 to leafy tufts. An extreme development of the plant which is more 

 common in certain ]>ortions of southern New England than typical 

 C. dentaius may be distinguished as 



C. DEXTATUs, var. ctenostachys, n. var. Spikelets 15-40-flowered, 

 tht; scale-tips less prominent. — Massachusetts, \Vest Pond, Ply- 

 mouth, September 23, 18G3 — type, September 13, 1853 (Wm. Bootf); 

 Middleborough Pond, September 9, 1870 (IVm. Boott); margin of 



1, 2, Muhl. Gram. 19 (1817). 3 Torr. Fl. 61 (1824). 



