SEGKEGATES FROM 8IEVEES1A. 175 



The type that has been called Geum iriflorum and Sieversia tri- 

 flora, differs from the last named as far as possible in aspect. The 

 accrescent and plumose character of the styles it has in common 

 with Sieversia, but its flowers are so different that there is no 

 comparison between them. They are analogous to those of 

 Horkelia as contrasted with Potentilla, that is, the calyx is 

 never expanded, and the petals are elongated and erect, never in 

 the least spreading. The genus has a remarkable range, occur- 

 ring from Labrador all the way across to the Pacific shores, 

 and southward as far as Mexico. The species are to be distin- 

 guished, jnst as in most Potentilla groups, by almost no charac- 

 ters of flower or fruit, but by good characters of foliage. The 

 red color of the calyx is nearly universal, and the mature styles 

 are as red underneath the plume ; and so I call the genus 

 Ertthbocoma. 



B. TBIFLORA. Geum triflorum, Pursh. Leaf-segments as- 

 cending, cuneiform, 1 to IJ inches long, almost parallel-nerved, 

 entire except near the apex, there deeply 3-toothed, or bifid and 

 each lobe 3-toothed : calyx-segments triangular-subulate, very 

 acute, much surpassed by the narrowly linear bractlets : petals 

 spatulate-oblong, obtuse, nearly equalling the bractlets : plume 

 of the achenes 2 or 2 J inches long. 



Elevated prairies and drift hills of Illinois, Wisconsin, Minn- 

 esota, aud the Dakotas. 



E. ciNBBASCENS. Allied to the last, but low, the foliage 

 barely half as large, subcinereously appressed-villous ; leaf -seg- 

 ments not half as large, more broadly cuneate, more deeply 3 to 

 5-toothed, less ascending on their rachis : flowers quite as large 

 as in the last, the red color of the calyx concealed by a denser 

 pubescence : plume of achenes hardly 2 inches long. 



Black Hills about Fort Meade, western S. Dakota, W. H. 

 Forwood, 1887 ; good specimens in U. S. Herb. 



E. AFFiNis. Also allied to E. triflora by broad segmentation 

 of foliage with segments entire except at summit, of subquad- 

 rate-cuneate outline, I to 1 inch long, deeply 3 to 5-toothed, not 

 notably ascending but spreading on their rachis, nearly glabrous 



