WESTERN SPECIES OF ARABIS. 75 



i 



Arabis poi.yci.ada. Rather loosely branching caudex sub- 

 ligneous, but not rigid, 3 or 4 inches high, its branches bear- 

 ing short leafy shoots and among them scapiform flowering 

 stems 3 to 5 inches high ; leaves of sterile shoots % inch long, 

 the small obovate obtuse blades shorter than the rather wide 

 petiolar part into which they are rather abruptly narrowed, the 

 whole whitish with a fine and dense stellate tomentum : flow- 

 ering stem and its few leaves perfectly glabrous and glaucous, 

 the leaves oblong, % inch long or less, sessile, not auricled : 

 flowers unknown : pods about an inch long, a line wide, 

 neither obtuse nor acute, straight or very slightly bent, hori- 

 zontally and secundly spreading on very short pedicels : seeds 

 in one row, suborbicular, winged narrowly, but all around. 



Farewell Gap, southern California, C. A. Purpus, 1897; the 

 collector's n. 5229 ; also well represented in Coville and 

 Funston's n. 1747 of 1891; from the same region, /. r., 

 mountains of Tulare County. 



Six species next subjoined are all akin to that group with 

 the smallest of flowers and the broadest of pods and seeds, of 

 which the type is ^. platyspenna. 



Arabis armerifolia, Low perennial, multicipitous above 

 a tap root, forming a tuft of short subligneous branches half 

 underground, each crowned with small leaves and, in its sea- 

 son, a slender subscapiform flowering stem or two, the whole 

 4 to 6 inches high above ground : leaves firm, not glaucous, 

 erect, /4 to H inch long, oblanceolate, obtuse, entire, glabrous 

 throughout ; the few cauline linear-oblong, sessile, shortly 



auricled 



not seen : 



pods 2 to 4 on each scape, erect, straight, about 1/i inches 

 long, little more than 1 line wide, abruptly acute, valves 

 thinnish for the group: seeds not very definitely biserial, 

 small, suborbicular, encircled by a very broad wing. 

 ! On a pumice stone slope in Crater Lake Park, southern 



i Oregon, F. V. Coville, 14 Sept., 1902; type in U. vS. Plerb. 



