122 
PLANTS OF YELLOWSTONE NATIONAL PARK 
brush and may be mistaken for it but their leaves are always brighter 
green in color, and the yellow flowers are much more showy. 
Chrysothamnus pumilis has numerous, erect, slender branches, 4 to 
12 inches high. The stems are very leafy and the bark is whitish. 
The leaves are linear and two-nerved. 
Chrysothamnus glaucus is similar, but it grows 20 to 40 inches high, 
and the leaves are lance-shaped. 
Chrysothamnus nauseosus differs from the other two species in 
having the stem and leaves covered with short white hairs. 
Chrysothamnus viscidiflorus has also been reported in the park but 
probably includes some of the above species. 
Pyrrocoma integrifolia is a perennial herb with alternate leaves 
and rather showy yellow heads containing both ray and disk flow¬ 
ers. It has several stems, 6 
to 10 inches high, and the 
heads are borne in the axils 
of the upper leaves, 1 to 
3 in each axil. The basal 
leaves are 3 to 6 inches 
long, while the stem leaves 
are smaller and lance-shaped 
or linear. The pappus is 
composed of rather rigid, 
yellowish or reddish-brown 
bristles. 
Geyser-daisy ( Pyrrocoma 
uniflora) is similar, but 
each stem bears only 5 or 6 or fewer leaves and usually only one head. 
Pyrrocoma lanceolata has stems that are more leafy and each stem 
bears 3 to 15 heads. 
Stenotus caespitosus is a low, smooth herb with a number of stems 
branching off from a somewhat woody base. The leaves are mostly 
basal but there are usually 3 or 4 on each stem. They are narrowly 
lance-shaped or linear and three-nerved. The heads contain both 
ray and disk flowers and both are yellow. The pappus is composed 
of bristles and is white. 
Stenotus acaulis is similar but more or less hairy. The genus is 
known as mountain-gold. 
Townsendia parryi is a low herb with a short, stout basal stem 
and upright flowering stems 2 to 4 inches high. It blooms very 
early in the season. The leaves are all on the lower parts of the 
stems, and both stems and leaves are covered with short white hairs. 
Figure 97. —Rabbitbrush. Yellow. Photograph 
by Dr. Harvey E. Stork. 
