GUM PLANT.
Grindelia robusta Nutt.
Range.—The gum plant (fig. 17) occurs in the States west of the Rocky Mountains.
Description.—The entire plant is covered with a resinous substance, which gives it a gummy, varnished appearance, whence its common name, gum plant, is derived.
This perennial of the aster family of plants has an erect habit of growth, and sends up a round, smooth stem about a foot and a half high, narrowly grooved and freely branching near the top, each branch terminating in a large yellow flower. The branches near the flower heads have a slightly reddish appearance.
The pale-green leaves are about an inch long, of a leathery texture, rather rigid, coated with resin, and show numerous translucent dots. The leaves are oblong-spatulate (having a gradually narrowed base below the broader rounded summit) and are more or less clasping at the base, the lower ones somewhat saw-toothed.
The yellow flowers are borne singly at the ends of the branches and measure about three-quarters of an inch across. The involucre (set of small leaves immediately beneath the flower) is very resinous and consists of numerous thick, overlapping scales, the tips of which are rolled forward.
Parts used and prices.—The flowering tops and leaves of this and of the scaly grindelia are collected indiscriminately, and bring from 5 to 12 cents per pound.
They are used in asthma and similar affections, and externally in cases of poisoning by poison ivy.