434 PATAGONIAN EXPEDITIONS I BOTANY. 



valves usually i -nerved. Seeds mostly 2-seriate in each cell. Cotyledons 

 accumbent. Pubescence, if any, simple. 

 Species 25, chiefly N. Temperate. 



i. RORIPA BONARIENSIS (DC. sub Nasturtiiim]. 



Annual, with pinnatipartite leaves ; the lobes distant, linear, subdentate, 

 glabrous. Silique suberect, terete-compressed, 2-3-times as long as the 

 Pedicel. 



(Argentina) ; Patagon., near Rawson (Dusen). 



"The Patagonian specimens always have white petals, often with a 

 rose tinge on the outside." (Speg.) 



2. R. PALUSTRIS (L.) Bess. Yellow Water-cress. 

 Erect, annual or biennial, nearly glabrous. Lower leaves petioled, 

 oblong or oblanceolate, pinnatifid, the lobes repand or toothed ; upper 

 leaves subsessile, dentate. Pedicels slender, 6 mm. long in fruit. Flowers 

 yellow, 5 mm. broad. Siliques linear or linear-oblong, as long as the 

 pedicels. Style i mm. 



(Eur., N. Amer.) ; Chubut, in marshes by Cabo Raso ; by Carren- 

 leofu, etc. 



3. R. PATENS Phil. 



Tall, branching, perennial (?). Lower leaves (?). Upper leaves dis- 

 tant, pinnate-lyrate ; pinnules 3 pairs, linear, entire or toothed, terminal 

 lobule oblong ; uppermost leaves simple. Racemes large ; peduncles 

 longer than the calyx, which is shorter than the white petals. Stigma 

 sessile. Siliques 2-5 cm. long, with horizontal pedicels, 4 mm. Valves 

 nerveless (not as in the other species). 



Patagon., in wet places by Rio Sta. Cruz and Lago Colu-huapi. Here 

 the color is slightly glaucescent ; lobes of leaves coarsely 3~5-dentate. 



4. R. PHILIPPIANA (Speg. sub Nasturtium; N. micranthumPh. non DC.). 



Branching annual, 20 cm. high. Leaves various, pinnatipartite with 

 broad segments to lyrate ; pinnce 2-4 pairs, dentate in the lower, entire 

 in the upper leaves ; the terminal lobe ovate, dentate. Silicles almost 

 erect, 12 mm. long by 1.5 mm. or thicker, on oblique pedicels 2-3 mm. 



Patagon., by Rio. Sta. Cruz; Golfo de S. Jorge: by Rio Negro, near 

 Carmen. 



