Polygonum davisiae
Encyclopedia
Polygonum davisiae is a species of flowering plant in the knotweed family
known by the common name Davis' knotweed.
to the Sierra Nevada, where it grows in high mountain habitat, such as talus
and fellfield
s.
, growing to a maximum erect height near 40 centimeters. 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 stipule
s 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.
Polygonaceae
Polygonaceae is a family of flowering plants known informally as the "knotweed family" or "smartweed family"— "buckwheat family" in the United States. The name is based on the genus Polygonum and was first used by Antoine Laurent de Jussieu in 1789 in his book, Genera Plantarum. The name refers...
known by the common name Davis' knotweed.
Distribution
It is native to the western United States from Washington and IdahoIdaho
Idaho is a state in the Rocky Mountain area of the United States. The state's largest city and capital is Boise. Residents are called "Idahoans". Idaho was admitted to the Union on July 3, 1890, as the 43rd state....
to the Sierra Nevada, where it grows in high mountain habitat, such as talus
Scree
Scree, also called talus, is a term given to an accumulation of broken rock fragments at the base of crags, mountain cliffs, or valley shoulders. Landforms associated with these materials are sometimes called scree slopes or talus piles...
and fellfield
Fellfield
A fellfield or fell field comprises the environment of a slope, usually alpine or tundra, where the dynamics of frost and of wind give rise to characteristic plant forms in scree interstices.-Soil dynamics:...
s.
Description
Polygonum davisiae is a perennial herb producing a decumbent or upright stem from a woody caudexCaudex
A caudex is a form of stem morphology appearing as a thickened, short, perennial stem that is either underground or near ground level . It may be swollen for the purpose of water storage, especially in xerophytes...
, growing to a maximum erect height near 40 centimeters. 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 stipule
Stipule
In botany, stipule is a term coined by Linnaeus which refers to outgrowths borne on either side of the base of a leafstalk...
s which is known as the ochrea
Ochrea
Ochrea, commonly spelled ocrea, is a structure formed of stipules fused into a sheath surrounding the stem. It is a diagnostic character in the Polygonaceae.In palms it denotes an extension of the leaf sheath beyond the petiole insertion....
.
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.