Field burrweed is a low-growing invasive winter annual species that is native to South America (Hickman 1993). Leaves are pinnate, leaflets +/- palmate and are softly short hairy and narrowly lanceolate; stems are many, often (but not always) purple-spotted or dark-coloured (Hickman 1993). Plants grow to 2 inches in height and 6 inches wide, though they are generally less than 25 cm diameter (Hickman 1993). Throughout its range, this species tends to establish in disturbed grassy areas, including hard-packed paths, where it out-competes lawn grasses. Field burrweed was first collected in British Columbia by Frank Lomer on May 18, 1996 at Ruckle Point Provincial Park, Saltspring Island, where it grew in a large patch "with many hundreds of small, more or less prostrate plants". (Lomer 1997).
Synonyms and Alternate Names:
Soliva daucifolia Nutt.
Soliva pterosperma (Juss.) Less.
Lomer, Frank. 1997. Six New Introduced Species in British Columbia. Botanical Electronic News 163. April 19, 1997.
Washington State Noxious Weed Control Board. 2010. Lawnweed (Soliva sessilis). Washington State Noxious Weed Control Board. Online. Accessed March 8, 2010.