Rydberg : Rocky Mountain flora 573 



Nebraska: Dismal River, 1893, Rydberg 14 1 4 (type); St. 

 James, 1893, Clements 2626 ; Pine Ridge, 1889, Webber ; Cedar 

 Island, 1854, Hayden. 



South Dakota : Piedmont and Little Elk Creek, 1892, Ryd- 

 bu~g 735 ; Cobbs Creek, 1894, T. A. Williams. 



Colorado: Merker, 1902, Osterhout 2602; Walsenburg, 

 1896, Shear 4 77 4 ; Canon City, 1896, Clements 101. 



Wyoming: Dayton, 1899, Tweedy 2631 and 2632. 



Suida stolonifera riparia var. nov. 



Leaves usually oval or elliptic, acute, thinner, lighter green 

 and less pale beneath than in the eastern type; bark on young 

 twigs brownish ; sepals and fruit smaller. 



In the field this variety looks very unlike the eastern S. 

 stolonifera. It grows as a high bush on river banks and is as far 

 as 1 know not stoloniferous. In the eastern plant the leaves are 

 comparatively thick, darker green above and very pale beneath, and 

 the young shoots bright red. The plant of the interior may 

 represent a distinct species, but on account of the lack of good 

 diagnostic characters it is perhaps better to regard it at present as 

 a variety of the eastern plant. The variety is the only form found 

 in the region of the Rockies and the Great Plains. It is common 

 from Manitoba, the Mackenzie River, to Alaska and south to 

 Nebraska, Colorado and Arizona ; as the type may be designated : 



Colorado: Crystal Creek, 1901, Baker 257. 



Aletes obovata sp. nov. 



Cespitose, glabrous, acaulescent perennial with deep tap-root ; 

 leaves 1-2 dm. long, pinnate with 4-5 pairs of leaflets ; these 

 broadly obovate, 1-2 cm. long, more or less cleft and toothed 

 with short ovate teeth, strongly veined beneath ; scapes 1-3 dm. 

 high, round-angled and striate ; bracts none ; branches of the 

 umbel 2-2.5 cm - l° n g in fruit; bractlets lanceolate, 3-4 mm. 

 long, reflexed in age ; pedicels very short or obsolete ; flowers 

 yellow ; calyx-teeth prominent, in fruit .5 — .75 mm. long ; fruit 5-6 

 mm. long and 1.5 mm. in diameter; ribs rather thick; oil-tubes 

 1 in the intervals, 2 on the commissure, rather large ; seed-face 

 only slightly concave. 



This species has been confused with the closely related A. 

 acaulis, which is easily distinguished by its rhombic, deeply cut 



