This section is from the book "Handbook Of Hardy Trees, Shrubs, And Herbaceous Plants", by W. Botting Hemsley. Also available from Amazon: Handbook of hardy trees, shrubs, and herbaceous plants.
Annual or perennial herbs, glabrous and glaucescent. Leaves much divided into linear segments. This genus is distinguished by the sepals of its calyx cohering in the form of a cap, which is pushed off by the expanding petals. Capsule linear. Named after a botanist. The four or five species are all natives of Northwestern America.
1. E. Galifomica. - This species was the first introduced. It is a straggling much-branched plant with large vase-shaped flowers, bright yellow in the typical form; but varieties with white, pinkish, paler yellow, and other tints are known.
2. E. tenuifolia. - A much smaller plant, with the segments of the leaves almost thread-like. Both are hardy and pretty, especially the former, and continue in flower for a long period.