86 PLANTS OF YELLOWSTONE NATIONAL PAttK 
The leaves are more or less elliptic in shape, and entire. The upper 
surface appears shiny as if varnished, while the lower surface is 
lighter and somewhat hairy. The leaves are strongly three-ribbed 
and 2 to 4 inches long. The flowers are white and small but are 
borne in large, showy, axillary clusters. When this plant grows 
on travertine it is a spreading and somewhat prostrate shrub. 
Figure 64.—Snowbrush. White. Photograph by Joseph S. Dixon, National Park 
Service. 
MALLOW FAMILY (MALVACEAE) 
This family is extremely important, because it is the family to 
which the cotton plant belongs. It also contains many plants with 
beautiful flowers, and many of these are used as ornamental plants. 
The well-known hollyhock, the sharon rose, and the hibiscus are 
familiar examples. The members of the family can usually be recog¬ 
nized readily by the flowers which have a 5-parted calyx, 5 petals, 
and many stamens which are united to form a column around the 
style. The styles are united at the base but separate above. 
Sphaeralcea rivularis is a stout plant with much-branched stems, 
2 to 4 feet high, and heart-shaped leaves that are deeply 5- to 7-lobed 
and coarsely toothed. The flowers are clustered on short branches. 
The petals are pale purple or whitish and about an inch long. 
Scarlet globemallow (Sphaeralcea coccinea ).—A low, spreading, 
much-branched and somewhat silky-hairy plant. The leaves are 3- 
to 5-parted and the divisions 2- or 3-cleft. The flowers are copper- 
scarlet or brick-red. 
