SUB-CLASS II. DIOOTYLEDONES. 185 



Bursa bursa-pastoris (L.) Britt. (Capsella bursa-pastoria 

 Moencb.) Shepherd's Purse.. A very common introduced 

 weed. Decorah (Savage), Calmar, etc. 



Camelina sativa (L.) Crantz. False Flax. An introduced 

 weed. (Fitzpatrick.) 



Draba caroliniana Walt. Carolina Whitlow-grass. In sandy 

 places. (Fitzpatrick.) 



Sophia intermedia Rydb. (Sisymbrium canescens Nutt., in 

 part.) Western Tansy-mustard. On dry ridges, etc. Decorah 

 (Savage). 



Arabis lyrata L. Lyre-leaved Rock-cress. On rocks, etc. 

 Locally common. Decorah. 



Arabis dentata T. & G. Toothed Rock-cress. In rocky places. 

 Decorah (Savage). 



Arabis laevigata (Muhl.) Poir. Smooth Rock-cress. On 

 rocky slopes, etc. Decorah (Savage). 



Arabis canadensis L. Sickle-pod. In woods, etc. (Fitzpat- 

 rick.) 



Arabis brachycarpa (T. & G.) Britt. {A. confinis S. Wats.) 

 Purple Rock-cress. In rocky places. (Fitzpatrick.) 



Erysimum cheiranthoides L. Worm-seed Mustard. Along 

 borders and on banks. Not rare. Decorah, etc. 



Berteroa incana (L.) DC. Hoary Alyssum. Not common. 

 Decorah. 



Family 3 . Capparidacece . 



Polanisia trachysperma T. & G. Large-flowered Clammy- 

 weed. In sandy places. Ft. Atkinson. 



Order 11. Rosales. 

 Family 1. Penthoracea. 



Penthorum sedoides L. Ditch Stonecrop. In low wet places. 

 Locally common. Decorah, etc. 



Family 2. Parnassiacece . 



Parnassia caroliniana Michx. Grass of Parnassus. Quite 

 rare, in bogs near Hesper. 



Family 3 . Saxifragacecz. 



Saxifraga pennsylvanica L. Swamp Saxifrage. Not rare, in 

 bogs. Hesper. 



