Aconogonon davisiae is a species of flowering plant in the knotweed family known by the common name Davis' knotweed. Aconogonon davisiae is native to the western United States from Washington, Oregon, and central and northern California (northern Coast Ranges and northern Sierra Nevada). There are also isolated populations in central Idaho It grows in high mountain habitat, such as talus and fellfields. Aconogonon davisiae is a perennial herb producing a decumbent or upright stem from a woody caudex, growing to a maximum erect height near 40 centimeters (3 feet). The leaves are oval and pointed or widely-lance-shaped to somewhat triangular, yellowish or pale green and waxy, slightly hairy, or smooth in texture. At the base of each leaf is a thin reddish sheath formed from the leaf's stipules which is known as the ochrea. Flowers occur in clusters of 2 to 5 in the leaf axils. The flowers are yellowish, greenish, or purple-tinged and just a few millimeters wide.