OF ARTS AND SCIENCES. 169 



JuNCUS ACUMiNATUS, Michx. At San Luis Potosi (552, 553 

 Schaffner) ; 893 and 895 Parry & Palmer. 



JuNCUs MARGINATUS, Rost. At Morales, Saa Luis Potosi (550 

 Schaffner) . 



JuNCDS xiPHioiDES, Meyer. At Morales (549 Schaffner) ; 897 

 Parry & Palmer. 



PoTAMOGETON NATANS, Linn. A Variety with oblong leaves acute 

 at each end. At San Luis Potosi (535 Schaffner), and at Guanajuato 

 (Duges). 



PoTAMOGETON HTBRiDDS, Michx. Near Morales (534 Schaffner) ; 

 856 Parry & Palmer. 



PoTAMOGETON PAUCiFLORUs, Pursh. Also near Morales (533 

 Schaffner) . 



Cyperus flavescens, Linn. At San Luis Potosi (569 Schaffner). 



Cyperus melanostachyus, HBK. At San Luis Potosi (568 

 Schaffner) ; 904 Parry & Palmer. 



Cyperus flavicomus, Michx. At Guanajuato (Duges) ; called 

 " Tule." The same as 431 Bourgeau. 



Cyperus aristatus, Rottb. Near Monclova, Coahuila (1330), 

 and San Rafael, San Luis Potosi (563 Schaffner). 



Cyperus Schweinitzii, Torr., van, with blunter scales and shorter 

 nutlets. Near Morales, San Luis Potosi (561 Schaffner); 907 Parry 

 & Palmer. The same as 703 Wright, referred to this species by Dr. 

 Torrey. 



Cyperus virens, Michx. At San Miguelito, San Luis Potosi 

 (562 Schaffner). 



Cyperus ? Near 0. acuminatus, Torr., but the tips of the 



scales less spreading and the nutlets oblong : contracted umbel sub- 

 lateral (one involucral bract stouter and erect). At Morales, San 

 Luis Potosi (564 Schaffner). 



Cyperus ? Of the same group with the last. Perennial, 



with a single dense sessile head, or with one or more additional rays, 

 the spikelets very numerous : scales very dark brown with green mid- 

 nerve, long-acuminate : nutlet sharply triangular, nearly as broad as 

 high. — At Pozos, San Luis Potosi (566 Schaffner) ; 905 Parry & 

 Palmer. 



Cyperus divergens, HBK. In the San Rafael Mountains, San 

 Luis Potosi (1032 Schaffner), and at Guanajuato (Duges) ; 910, 911 

 and 911^ Parry & Palmer; 1612, 1623 Coulter. The same as 256 

 Hartweg, so named by Bentham. The scales at length become white 

 and scarious. 



