240 LEGUMINOSAE (PULSE FAMILY) 
erect and some reclining on the ground for most of their length. 
The whole plant is densely covered with long, white, silky hair. 
Leaves alternate, odd pinnate, five to eight inches in length, com- 
posed of seventeen to twenty-nine leaflets, pointed-ovate, and 
about a half-inch long; petioles slender, with membranous pointed- 
ovate stipules united to their bases. The 
peduncles spring from the lower axils and are 
longer than the leaves, so that the short, 
dense spike of deep purple or violet flowers 
is held above them; each flower is a little 
more than a half-inch long, and has a tubular 
calyx with five nearly equal teeth, an erect, 
oblong standard, narrow wings, and a blunt 
keel. Like the rest of the plant, the flower 
is hairy; the pods, however, are smooth, 
dry, leathery, about three-fourths of an inch 
7 long, slightly incurved, grooved at the sutures, 
two-celled, each cavity containing a number 
of seeds, which have very long vitality when 
in the soil. (Fig. 171.) 
Means of control 
During the years 1881 to 1885 the State of 
Colorado paid a bounty of 21 dollars a ton, 
dry, “for any Loco or poison weed dug up not 
Fic. 171. — Woolly less than three inches below the surface of 
As aged sei the ground, during the months of May, June, 
‘ : and July.” After about two hundred thou- 
sand dollars had been spent, the law was repealed. But the ex- 
periment proved that if these plants are cut off at the root, well 
below the crown, when they are in full bloom, they never sprout 
again, but die. And a man with a sharp spade or a sharp and 
heavy hoe can destroy the plants very rapidly, cleansing a large 
extent of ground in a day. Dormant seeds may furnish another 
crop; but if successive germinations are cut off before developing 
seed, the ground will be cleansed in the course of two or three 
seasons at a much less expense than is now suffered in losses of 
live-stock in a single year. 
