80 
PLANTS OF YELLOWSTONE NATIONAL PARK 
Lupine (Lupinus). —The wild lupines are easily recognized, because 
they are the only members of the pea family in our flora with 
strictly palmate leaves and five or more leaflets. The different species, 
however, are often quite difficult to distinguish. The following 
species have been identified in the park: Lupinus argenteus , Z. 
Imrkei, Z. caespitosus , Z. candicans , Z. decmribens , Z. flexuosus , Z. 
laxiflorus, L. leucophyllus , L. macounii , L. montioola , Z. parviflorus , 
and Silky lupine (Z. sericeus). 
Vicia linearis and American vetch ( Vida americana ) are the only 
members of the pea family in our flora that climb by means of 
tendrils at the ends of the pin¬ 
nate leaves. The purple flowers 
are quite large and are borne, 3 
or 4 on a short stem, in the axils 
of the leaves. The former species 
has narrow linear or oblong 
leaves, while the latter has ovate 
or oval leaves. 
Hedysarum cinerascens grows 
1 to 2 feet high and the stems 
are covered with short, ashy 
hairs. The leaves have 9 to 13 
oblong leaflets and the flowers are 
borne on stems that are somewhat 
longer than the leaves. The flow¬ 
ers vary from rose color to lilac 
or purple. The pods are com¬ 
posed of several roundish, nearly 
Figure 58.—Lupine. Bluish purple. Smooth, Separable joints COn- 
Copynght, j. e. Haynes. nected in the middle. 
Hedysarum sulphurescens has bright yellow flowers. 
This genus is commonly known as sweetvetch. 
Glycyrrhiza lepidota is an upright plant with a large and sweet 
root and with creamy-white flowers borne in dense axillary spikes. 
The stems are 1 to 3 feet tall, and the leaves have 11 to 19 oblong 
or lance-shaped leaflets. The brown pods are thickly covered with 
hooked prickles. 
The genus is commonly called licorice. 
Milkvetch (Astragalus ).—The plants of this genus are all herbs 
with pinnate leaves and with flowers in spikes or racemes. The 
calyx is five-toothed. The corolla is long and narrow. The standard 
is as long or longer than the wings and keel and its sides are bent 
outward or backward. Nine of the stamens are united while the 
