Astragalus, Tourn. Pea Family.
Herbs, or sometimes plants woody at base. Leaves.—Alternate; with stipules; unequally pinnate. Flowers.—Rather small; chiefly in simple axillary spikes or racemes, upon a commonly elongated peduncle; papilionaceous. Calyx.—Five-toothed. Corolla and its slender-clawed petals usually narrow. Keel not pointed. Stamens.—Nine united; one free. Ovary.—One-celled; sometimes apparently two-celled. Pod.—Very various; commonly inflated. Seeds.—Few to many on slender stalks; generally small for the size of the pod.
The genus Astragalus is a very large one, comprising many species in most parts of the world, save Australia and South Africa. About two hundred species are native of North America, most of which are found in the region west of the Mississippi River. Of these several are known as "loco-weed," and are poisonous to sheep and cattle.
Very few species of this genus have any economic value. A. gummifer and some other similar species of Western Asia, low, spiny shrubs, yield the gum tragacanth of commerce.
Œnothera, L. Evening-Primrose Family.
Herbs, or plants sometimes woody at the base. Leaves.—Alternate. Flowers.—Axillary or in spikes or racemes. Calyx-tube.—More or less prolonged above the ovary with four reflexed segments.
Petals.—Four; obcordate to obovate; sessile; yellow to white, often tinged with red or turning red in fading. Stamens.—Eight; equal; or those opposite the petals shorter. Anthers perfect; two-celled; versatile. Ovary.—Four-celled; many ovuled. Style filiform. Stigma four-lobed or capitate. Fruit.—A capsule with the seeds in one or two rows in each cell.
The name Œnothera is from two Greek words, meaning wine and a hunt, or pursuit. Mr. Gray tells us that it was given in ancient times to some plant whose roots were eaten to provoke a relish for wine.
This is a large genus, containing a hundred or more species, which are mostly confined to America, about a quarter of them being Californian. Many of them are very beautiful and have long been favorites in gardens. The flowers are yellow or white, and are commonly designated as "evening primroses," as many of them open upon the edge of evening.