326 Rydberg: Studies on the Rocky Mountain flora 



Carlton 6283; Fish Lake, August 2, 1909, Garrett 2578; Elk Moun- 

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

 August 11, 1911, 9628; Mount Ellen, July 25, 1894, M. E. Jones 

 56840; 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. subpinnatifida 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 A. 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, 7". M. Macoun 

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

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

 /. M. Macoun 63496. 



Alberta: Trail to Lake O'Hara, August 8, 1904, John Macoun 

 64517 in part. 



Parrya platycarpa sp. nov. 

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



macrocarpa R. Br. 182 1. 



