492 RypBERG: NOTES ON ROSACEAE 
sepals in length; in S. triflora the hypanthium at least in anthesis 
is acute at the base and the bractlets much exceeding the sepals 
in length. If so characterized, Sieverisa triflora takes in all the 
forms growing on the prairies or plain region east of the Rockies 
and extending into Montana and Wyoming. 
Erythrocoma cinerascens Greene and E. affinis Greene I can not 
distinguish from it. The former is a depauperate form, I take to 
be due to a higher altitude, represented by most specimens from 
the Black Hills and Wyoming. The latter is the high northern 
form with narrower leaflets and brighter coloration. If held 
distinct it had two older names than that of Dr. Greene, viz. 
Sieversia rosea Graham and Geum Grahami Steudel. 
Sieversia grisea (Greene) Rydb. The following proposed 
species of Erythrocoma, viz. E. grisea, E. arizonica, E. tridentata 
and E. aliena, all by Greene, have many characters common 
with S. triflora, viz. the habit, leaf-form and toothing, pubescence, 
and styles, but the hypanthium is not acute at the base, the petals 
are broader and the bractlets shorter, slightly if at all longer than 
the sepals. 
They were all described from Arizona and Chihuahua, but 
the same forms are common in Colorado and rarely as far north 
as Montana and Washington. They constitute the mountain 
representatives of S. triflora. Of these Erythrocoma grisea is the 
first one in the list. The type does not represent the common 
form, but is a depauperate form with short leaves, standing in 
the same relationship to the common form as E. cinerascens 
Greene stands to Sieversia triflora. The common better-developed 
form represents E. arizonica and is common in Colorado. £.- 
tridentata is a form with looser pubescence and narrower leaflets, 
otherwise not distinguishable from E. arizonica. E. aliena is 
exactly the same as E. grisea. 
Erythrocoma australis I regard as a hybrid between Sieversia 
grisea and S. ciliata. See my notes in the North American Flora. 
Steversia canescens (Greene) Rydb. The forms of Erythro- 
coma of the mountains of California, Oregon and Washington 
differ very little from S. grisea, as here understood, except in a 
denser pubescence and shorter bracts. It is doubtful if they 
should be regarded as a distinct species. I retained, although 
