Shakkr : Vascim.ak Ki.ora (ik Ai.lkghknv Couniv. 23 



=i^ A. dentata (Torrey). Toothed rock-cress. 



Neville rownshi]), south shore of island, May 3, 1890; O'Hara 

 Township, river bank near Ross Station, May 9, 1900. 



''■f A. laevigata (Muhlenberg). Smooth rock-cress. 

 ■'■^- A. laevigata Burkii Porter. Hurk's rock-cress. 

 ■> A. Canadensis Linnreus. Sickle-pod. 



f A. glabra (Linnaeus). Tower mustard. 



A. perfoliafa Lamarck. 



DRABA Linnffius. 

 =^ D. verna Linnaeus. Whitlow-grass. 



KONIGA Adanson. 

 AL KS'^^yJ/Tournefort. 



* K. maritima (Linnaeus). Sweet alyssum. 



Sewickley, "ashery," foot of Walnut street, August, 1892. 

 Spreading ! .-August 10, 1897. 



RORIPA Scopoli. 

 NASTURTIUM R. Brown. 

 f R. Nasturtium (Linnaeus). Water-cress. 

 N. officinale R. Brown. 



* R. palustris (Linnaeus). Marsh -cress. 

 N. paliistre De Candolle. 



* R. Armoracia (Linnaeus). Horseradish. 



BARB ARE A R. Brown. 



* B, Barbarea (Linnn^us). Common winter-cress. 



B. vulnif'is R. Brown. 



