235 Rydberg : Studies on the Rocky Mounjain Flora 



Thlaspi Nuttallii 



TJilaspi cocJilcariforuie Nutt. Journ. Acad. Phila. 7 : 13. 1834. 

 Not DC. 1 82 1. 



This species has been merged in T. alpestre, but none of our 

 American forms belong to that species. T. Nuttallii is inter- 

 mediate between T. payvifloruin A. Nelson and T. glauciivi A. 

 Nelson, having larger flowers than the former and smaller than 

 the latter. The pod is obovate, rounded at the apex with a narrow 

 sinus. In T. glaucmn the sinus is broad and open. 



Roripa clavata sp. nov. 



Biennial, tall, perfectly glabrous : stem 6-IO dm. high, simple 

 up to the inflorescence: leaves lyrate-pinnatifid, 5-10 cm. long, 

 more or less auricled at the base ; lobes 4-8 pairs, oblong to ovate, 

 obtuse or acute, broadly dentate : inflorescence branched ; petioles 

 in fruit 5-10 mm. long, divaricate: petals spatulate, about 3 mm. 

 long, exceeding the sepals : pod 10-12 mm. long, 2.5-3 mm. thick, 

 decidedly clavate, obtuse, strongly curved ; style nearly i mm. long. 



This may have been included in Watson's Nasturtium terrestre 

 var. occidentale ; but the name occidcntale cannot be used as there 

 is already another older Roripa occidcutalis Greene. It is not, 

 however, Roripa Pacifica Howell, which is supposed to be a syno- 

 nym of Watson's variety, for that species is described as being 

 slightly pubescent and having pods which are acute at both ends, 

 while in R. clavata the pod is almost truncate at the apex. 



Washington: Hogeman, Chehalis county, 1897, Frank H. 

 Lamb, 122 1 (type in herb. N. Y. Bot. Gard.) ; West Klickitat 

 county, 1885, W. M. Suksdorf. 



Oregon : Sauvie's Island, 1888, T. Hoivell, ijjj. 



British Columbia : Port Henry, i88g,/o/m Macoun. 



Idaho: Near Hope, Kootenai county, 1892, Sandberg, Mac- 

 Dougal & Heller, 102^, at least in part. 



Roripa Underwoodii sp. nov. 



Biennial, divaricately branched, even near the ground, perfectly 

 glabrous ; stems 2 dm. or more high : leaves 3-5 cm. long, lyrately 

 pinnatifid, thin ; lobes oblong, obtuse ; the terminal one elliptic 

 to broadly oval, sinuately toothed ; petioles short, winged and 



