1916] NELSON & MACBRIDE—WESTERN PLANTS I51 
CHAENACTIS MAINSIANA Nels. and Macbr. Bor. Gaz. 56:478. 
1913.—In the recent treatment of this genus in the North American 
Flora, the above species is reduced to C. pumila Greene (34:73. 
1914). The latter is described as having the leaves ‘broadly 
obovate in outline,” but in the key (l.c. 66) it is placed under the 
subdivision “leaves oblanceolate or ellipitic in outline.”” The sub- 
division parallel to this reads “leaves obovate cuneate or flabelli- 
form in outline.” Under this heading are placed C. nevadensis 
and C. Evermannii. The latter is scarcely more than a variety of 
the former, and in our publication we compared C. Mainsiana to 
these species, and according to the key referred to, it would have 
to be placed with these species because it has flabelliform leaves. 
But admitting that the key is fallacious (witness the disposition of 
»C. pumila), let us compare C. Mainsiana with that species. C. 
pumila Greene, Leaflets 2:221 (not 223 as in North American 
Flora) 1912, has “densely glandular-hirsute involucres’’ and 
“densely glandular peduncles” which are only 2-4 cm. long. 
These are characters which belong to C. alpina in greater or less 
degree, but are absolutely at variance with the characters of C. 
Mainsiana. The latter species, even when young, is greenish gray 
with a lepidote tomentum which is sprinkled with resinous atoms 
as in Artemisia atomifera Piper, and the peduncles, which usually 
bear more than one head, rise 5-10 cm. above the leaves. It is 
evident, therefore, that the nearest relative of this species is 
C. nevadensis, the species to which we originally compared it (J.c.); 
and it is very much more distinct from C. nevadensis than is C. 
Evermannii Greene, maintained in the North American Flora. 
Evax breviflora (Gray), n. comb.—E. caulescens (Benth.) Gray, 
var. brevifolia Gray, Syn. Fl. 1:229. 1888; Hesperevax brevifolia 
Greene, Fl. Fran. 402. 1897.—JEPSON has raised the var. sparsi- 
_ flora Gray to specific rank, and it seems to us that the above variety 
deserves equal recognition. E. brevifolia has the heads in terminal 
clusters as in the species, but the leaves resemble those of E. sparsi- 
flora. Asa result, the aspect of the plant is distinctive. Further- 
more, each species is confined to its own range; E. brevifolia grows 
in northern California and southwestern Oregon, and is the north- 
ernmost species of this group of curious composites. 
