Field Madder (Note: This is a broadleaf weed, not a true grass)
Sherardia arvensis · Cool-season, Annual broadleaf (C3 metabolism)
Grass Family
Rubiaceae (Madder Family), not Poaceae
Grass Category
Invasive/Weed Grass mimic; commonly found in lawns and pastures
Variety / Cultivar
None (Wild type species)
Hardiness Zones
USDA Zones 5-10; thrives in cool, moist spring conditions and may die back in extreme summer heat.
About This Grass
A low-growing, herbaceous annual that forms a dense, circular mat. While it superficially resembles a fine-textured grass from a distance, it features whorled leaves and tiny, pale lilac to pinkish-white flowers at the tips of the stems.
Blade Characteristics
Leaves are not true blades; they are lanceolate, arranged in whorls of 4-6 around the stem, roughly 5-10mm long, with pointed tips and tiny prickles on the margins. Color is a medium to bright green.
Root System
Slender, branched taproot that is relatively shallow; easy to pull manually, but forms a dense surface mat that outcompetes turf seedlings.
Growing Information
Origin Region
Native to Europe, North Africa, and Southwest Asia; naturalized throughout North America
Growth Habit
Prostrate, spreading mat-former; stems branch from the base and creep locally
Sunlight & Water Needs
Full sun to partial shade; prefers moist, well-drained soils but highly adaptable to poor, sandy, or disturbed ground.
Mowing & Maintenance
Grows very low to the ground (1-3 inches), often escaping mower blades. Maintenance involves broadleaf herbicide application or improved turf density to crowd it out.
Special Characteristics
High tolerance for low mowing heights; highly effective at colonizing bare soil spots in lawns; easily identified by square stems and whorled leaf patterns.
Ecological Information
Introduced species in North America; can be invasive in disturbed habitats; provides nectar for small pollinators despite its status as a common turf weed.