Origin:
Native to Eurasia, but a serious turf problem in the United States from Texas to Florida, and in many other tropical regions of the world.
Biology:
This is a summer annual which spreads quickly to form wide, dense mats over turf. Reproduction is from seeds. Plants have a taproot and numerous smaller spreading roots, and may be difficult to pull from the soil.
Identification:
Numerous stems grow prostrate and spreading. The leaves are opposite and narrow, with dark green, shiny surfaces. Where they attach to the stems their stipules form a cup-like collar around the stem. Flowers emerge from the axils of the leaves, on long stalks and in groups of two or more. They are very small, white, and with the petals kept close together to form a tube.
Characteristicts Important to Control:
This weed appears to be tolerant of many herbicides. Physical removal of plants and use of a pre-emergent to stop germinating seeds can be effective. In turf a selective broadleaf herbicide will be needed.