2 Contributions from the Gray Herbarium 
that are very difficult to describe. For instance, students have 
long recognized that the genus, by reason of differences of aspect, 
falls into several natural and recognizable groups, which often 
appear to lack technical means of separation. A character is pro- 
posed to separate two such groups, viz.: the Lanceolatae and the 
Oblongifoliae, which is believed to be valid in so far as those sections 
are concerned, but it is of no value in separating the Alpinae, which 
happen to be well-marked, however, by their subsessile anthers. 
This character, the presence or absence of a ring of hairs near the 
base of the corolla-tube, has been used by Nelson as a specific 
difference. In order to determine the constancy of the character 
over one hundred corollas were boiled, dissected and studied criti- 
cally in relation to the other characters of the particular specimens 
concerned. : 
While the present revision aims to cover the western United 
States a few species are omitted, notably M. symphytoides Greene, 
Pl. Baker. iii. 20 (1901) and M. tubiflora Rydb. Bull. Torr. Club 
xxvi. 544 (1899). I have seen no authentic material of these, but 
if I may judge from the inadequate characterization of the former, 
it is very near to a variety of M. arizonica Greene. The latter (M. 
tubiflora) seems to be related to M. oblongifolia Soe cat G. Don, 
and perhaps is distinct. 
I am indebted to Dr. Aven Nelson, Curator of the Rocky Moun- 
tain Herbarium at the University of Wyoming, and to Mr. W. R. 
Maxon, Curator of the National Herbarium at Washington, D. C.., 
for the loan of valuable specimens, including many types. The 
abbreviations “ R. Mt. Herb.” and “ Nat. Herb.” follow the cita- 
tions of specimens from these institutions respectively; otherwise 
the specimens cited are in the Gray Herbarium. 
EvUMERTENSIA — Kry To SEcTIONS AND SpEcIES oF WESTERN NoRTH 
AMERICA 
Leaves with distinct lateral veins or net-veined, large, the 
middle cauline 6-12 em. long; aestival re geass s, 3-12 dm 
gh, growing tty streams or in woods below timber- 
ing the other characters is Cage POOR ie A els Group I. 
Calyx-lobes acute or acuminate, usually’ longer than the fruit, 
always none or less tr clair? in outline, distinctly so if 
shorter yore Site TPE 6 es verve. caus Subsect. PANICULATAE. 
