18 PITTONIA. 
late-obovate; achene with a stout triangular beak. rather. 
longer than the obtusely trigonous body. 
Mountains of New Mexico, near Santa Rita del Cobre. 
ERr0GoNUM sUBALPINUM. Near E. umbellatum, the foli- 
age, pubescence and umbels similar, but less woody at base, 
the branches shorter and quite prostrate; scapiform pedun- 
cles stoutish, erect, 8 to 14 inches high, bearing a simple 
large umbel of 8 to 12 rays; perigonium large, cream-colo 
tinged with rose in age, the stipe-like base long, its artic 
lation with the pedicel enlarged; inner segments accrescent, 
eventually distinctly surpassing the outer ones. ah 
This very common Rocky Mountain species is a plant long 
confused with E. umbellatum as a mere albino state of it; and 
its segregation will never, by the mere herbarium botanist, 
be seen to be necessary, unless some anatomical charac 
unrecognized by me shall be found. To no one is it be 
known than to me, that in this large genus many sp 
normally deep-yellow-flowered, vary to cream-colored albin 
. States. Yet, in the face of this knowledge, and with no other 
— characters than the more herbaceous and depressed mode of 
growth, coupled with the inequality between the outer and 
inner segments of the perianth for this species, I confidently 
express my opinion that it isa species. Even in the rare 
instances of its growing along with E. umbellatum, as it does 
ou the very high and subalpine plains of Wyoming, I should 
be able to distinguish the two at a glance, even were the — 
flowers of the same color, so different are they in habit. — 
In geographieal distribution, they are interesting subjects 
of comparison. In middle Colorado, where twenty-six years 
exclusion of the other; and it is only after having left t 
