326 Rydberg: Studies on the Rocky Mountain flora 



Carlton 628 j; Fish Lake, August 2, 1909, Garrett 2578; Elk Moun- 

 tains, August 8, 191 1, Rydberg & Garrett 9552; Head of Dry Wash, 

 August II, 191 1, 9628; Mount Ellen, July 25, 1894, M. E. Jones 

 5684g; Logan Canyon, June 28, 1910, C. P. Smith 2226. 



Arabis MacDougalii sp. nov. 



Perennial; stem 4-6 dm. high, simple below, densely stellate- 

 pubescent; basal leaves narrowly oblanceolate, 2-4 cm. long, 

 entire or denticulate, densely stellate-pubescent; stem leaves 

 linear or linear-lanceolate, sagittate at the base; sepals oblong, 

 stellate-pubescent; petals white, oblanceolate, 5-6 mm. long; 

 pedicels in fruit reflexed, 5-10 mm. long; pods finely stellate- 

 pubescent, reflexed, 4-5 cm. long, 1.5 mm. wide; seeds in one row. 



This species is related to A. suhpinnatifida but differs in its 

 smaller white petals and its entire leaves. 



Montana: Old Sentinel, near Missoula, June 12, 1901, Mac- 

 Dougal 191 (type, in herb. N. Y. Bot. Garden). 



Nevada: King Canyon, Ormsby County, June 4, 1902, C. F. 

 Baker 986 (referred here doubtfully). 



Arabis brevisiliqua sp. nov. 



Biennial; stems 3-4 dm. high, sparingly stellate-pubescent 

 below, otherwise glabrous; basal leaves narrowly oblanceolate, 

 1-2 cm. long, finely stellate-pubescent; stem leaves linear, sagittate 

 at the base, glabrous; sepals scarious-margined, 3 mm. long, 

 glabrous or nearly so; petals purplish, about 6 mm. long; pedicels 

 in fruit 3-5 mm. long, recurved pods 2-3 cm. long, 2 mm. wide, 

 glabrous; seeds in two rows. 



This species resembles .4. lignifera A. Nels., but the pod is much 

 shorter, less than 3 cm. long, with the seeds in two rows, and 

 the sepals are glabrous instead of stellate-pubescent. 



British Columbia: Skagit Valley, July 6, 1905, /. M. Macoun 

 70825 (type, in herb. N. Y. Bot. Garden) ; near international 

 boundary, between Kettle and Columbia rivers, July 16, 1902, 

 J. M. Macoun 63496. 



Alberta: Trail to Lake O'Hara, Augusts, 1904, John Macoun 

 64S17 in part. 



Parrya platycarpa sp. nov. 

 Parrya niacrocarpa S. Wats. Bot. King Exp. 14. 1871. Not P. 



macrocarpa R. Br. 1821. 



