''Polygonum paronychia'' is a species of flowering plant in the
knotweed family known by the common names dune knotweed, black knotweed, and beach knotweed.
[ It is native to the coastline of western North America from ]British Columbia
British Columbia (commonly abbreviated as BC) is the westernmost province of Canada, situated between the Pacific Ocean and the Rocky Mountains. It has a diverse geography, with rugged landscapes that include rocky coastlines, sandy beaches, ...
to California
California is a state in the Western United States, located along the Pacific Coast. With nearly 39.2million residents across a total area of approximately , it is the most populous U.S. state and the 3rd largest by area. It is also the m ...
, where it grows in sandy coastal habitat such as beaches, dunes, and scrub.
Description
''Polygonum paronychia'' is a small prostrate or upright shrub producing multibranched brown stems up to a meter (40 inches) long. The stems may root at nodes that come in contact with moist substrate. The leaves are alternately arranged on the stems but are mostly located bunched around the tips of the stem branches. The leaves are linear to lance-shaped with rolled edges and bristly midribs on the undersides. Each leaf has a large stipule
In botany, a stipule is an outgrowth typically borne on both sides (sometimes on just one side) of the base of a leafstalk (the petiole). Stipules are considered part of the anatomy of the leaf of a typical flowering plant, although in many speci ...
which forms a wide, membranous ochrea
An ochrea (Latin ''ocrea'', greave or protective legging), also spelled ocrea, is a plant structure formed of stipules fused into a sheath surrounding the stem, and is typically found in the Polygonaceae
The Polygonaceae are a family of flow ...
. The ochrea is up to 2 centimeters (0.8 inches) long and is persistent, fraying into fibrous, silvery shreds that remain on the plant through the seasons. Flowers occur in the leaf axils. Each is up to a centimeter (0.4 inches) wide with five narrow white or pinkish corolla lobes.[Flora of North America, ''Polygonum paronychia'' Chamisso & Schlechtendal, 1828. Beach or black or dune knotweed ]
/ref>
Uses
The plant has been made into a poultice to treat whitlow infections.
References
External links
Jepson Manual TreatmentCalphotos Photo gallery, University of California
paronychia
Paronychia is an inflammation of the skin around the nail, which can occur suddenly, when it is usually due to the bacterium ''Staphylococcus aureus'', or gradually when it is commonly caused by the fungus ''Candida albicans''. The term is fro ...
Flora of the West Coast of the United States
Flora of British Columbia
Plants described in 1828
Flora without expected TNC conservation status
{{Polygonaceae-stub