PLANTS FROM NORTH DAKOTA 1 3 



oval, with cuneate base and acutish apex, either entire or with 

 2 or 3 shallow apical lobes, the petiole equalling to twice as long as 

 the lamina. Cauline leaves either entire, narrowly elliptical, 

 or deeply cleft almost to the base, with the median lobe large, 

 broader (entire or with 2 or 3 shallow apical lobes), and the lateral 

 ones linear, or with all the lobes linear. Petals small, narrowly 

 obovate, 5-8 mm. long, 3-5 mm. broad, exceeding the sepals. 

 Head of carpels spherical. Achenes glabrous, plump, dorsally 

 rounded, with a short hooked beak. 



If we locate the species in the system, we will find it belonging 

 to the R. glaberrimus group, which has the following members. 

 (i) R. glaberrimus Hook, of the Pacific coast, which is glabrous, 

 with broad and broadly 3-lobed radical leaves, entire cauline 

 leaves, large petals, 10-12 mm. long, 8-10 mm. broad, broadly 

 obovate, brighter yellow, achenes with a slender beak, herbage 

 becoming black in drying; {2) R. ellipiicus Greene, of the Rocky 

 Mountains of Colorado, Utah and Nevada to eastern California, 

 which is glabrous, has always entire, acute radical leaves, usually 

 3-cleft cauline leaves, large petals as in R. glaberrimus, often 

 even more rounded, achenes with a short, curved style, and herbage 

 remaining green in drying; and (3) R. Waldronii, chiefly of the 

 prairies of eastern Montana and western Dakota, glabrate (or 

 glabrous), leaf-characters generally of R. ellipticus, but often at 

 the same time partly coming nearer to R. glaberrimus , small and 

 narrowly obovate petals, 5-8 mm. long, 3-5 mm. wide, achenes 

 with a short, curved style, and herbage not changing color in dry- 

 ing, the flower and the whole plant just equalling in size young 

 specimens of our own R. ovalis Raf. The size and shape of the 

 petals certainly deserve specific distinction. The type was col- 

 lected on May 14, 19 12 in a moist pasture at Dickinson, Stark 

 County, in the southwestern part of this state. It has been named 

 in honor of its first collector, Mr. Clarence H. Waldron, the junior 

 representative of a North Dakotan family of botanical fam.e. 



Leeds, North Dakota. 



