WIGHT: ERITRICHUM IN NorTH AMERICA 409 
This plant, briefly described by Dr. Rydberg as a variety of 
£. aretioides, differs from both the true aretioides and the Rocky 
Mountain plant hitherto identified as such in the nutlets not hav- 
ing a toothed border, but instead a ridge-like margin which allies 
it to &. Howardi. A description of the nutlets was omitted in the 
original description, although well-developed nutlets were found 
Nutlets of EZritrichum, X10. a, E. aretioides ; 6, E. chamissonis; c, E. splen- 
dens; d, EB. elongatum,; e, £. Howardi; f, E. argenteum, 
on the plant in the United States National Herbarium collected by 
Rydberg and Bessey (no. 4891). It differs from Z. Howard, its 
nearest relative, in being a smaller plant, and in its oblanceolate 
leaves, its spreading pubescence and its smaller flowers. A plant 
of alpine or subalpine distribution in northern Colorado, Wyoming © 
and western Montana to eastern Oregon. 
Specimens have been examined as follows : 
Cotorapo: Alpine Ridges, Middle Park, 1861, C. €. Parry ; 
Gray’s Peak, 1 1,000—14,000 ft. alt., 1885, A. WV. Patterson, ro9. 
Wyomine: Head of Big Goose Creek, Big Horn Mountains, 
1893, Frank T: weedy, 43; Dome Lake, 1896, Aven Nelson, 2433. 
Montana: Belt Mountains, 9,000 ft. alt., 1883, 7. L. Scribner, 
773 ; ©-7,000 ft. alt., 1887, R. S. Williams, 1078. Park county, 
1889, Frank T, weedy. Spanish Basin, Gallatin county, 5—6,000 ft. 
alt., 1897, kydberg & Bessey, 4891. Old Hollowtop, near Pony, 
— about 9,000 ft. alt., 1897, Rydberg & Bessey, 4890. Bald Mountain, 
10,000 ft. alt., 1880, Sereno Watson, 245. 
