Lesser Swinecress (Note: This is a broadleaf weed, not a true grass)
Lepidium didymum (formerly Coronopus didymus) · Winter Annual; C3 photosynthesis; Broadleaf Herb (Not a true botanical grass)
Grass Family
Brassicaceae (Mustard Family)
Grass Category
Invasive/Weed common in turf and landscapes
Variety / Cultivar
None specified; wild-type species
Hardiness Zones
USDA Zones 5-11; very cold tolerant during winter rosette stage; dies back in high summer heat in warmer climates.
About This Grass
Low-growing, spreading herb often mistaken for a grass in its early stages. It forms a flat rosette and eventually decumbent branches with highly dissected leaves. It has a distinctive skunky or pungent odor when crushed.
Blade Characteristics
Leaves (not blades) are alternate, pinnately lobed or deeply divided; segments are narrow and may appear linear. Leaf texture is smooth, color is medium green; lacks grass-specific features like ligules or auricles.
Root System
Strong central taproot with smaller lateral fibrous roots; allows it to persist in compacted soils; low thatch tendency; establishes quickly in bare spots.
Growing Information
Origin Region
Native to South America; naturalized globally in temperate and subtropical regions
Growth Habit
Prostrate, mat-forming, spreading via decumbent stems from a central taproot
Sunlight & Water Needs
Full sun to partial shade; prefers moist, fertile soils but can withstand significant drought via its taproot; thrives in high-nitrogen environments.
Mowing & Maintenance
Extremely resistant to mowing due to prostrate growth habit (branches stay below blades). Managed via pre-emergent or broadleaf post-emergent herbicides.
Special Characteristics
High foot-traffic tolerance; highly invasive in lawns; distinctive pungent odor; easily identifies by its tiny, paired heart-shaped seed pods (silicles).
Ecological Information
Introduced/Invasive status in many areas; provides little wildlife value in turf; often indicates soil compaction or high nutrients; difficult to eradicate once seed bank is established.