Lady's Thumb (Smartweed)
Persicaria maculosa · Warm-season, Annual, C3-C4 intermediate
AI-generated identification · may be incorrect
Grass Category
Invasive/Weed Grass
Hardiness Zones
USDA Zones 3 through 9, highly adaptable
Grass Family
Polygonaceae
Variety / Cultivar
Wild type
About This Grass
An annual herbaceous plant often mistaken for grass due to its slender stems and narrow leaves, featuring distinctive pink to purplish flower spikes and swollen joints with ocreae.
Blade Characteristics
Lanceolate leaves with smooth margins, pointed tips, medium width, medium green often with a dark blotch in the center, rolled vernation, membranous ochrea instead of a traditional ligule
Root System
Shallow fibrous root system, fast establishment, low thatch, poor drought tolerance
Growing Information
Origin Region
Europe and Asia, widely naturalized globally in temperate regions
Growth Habit
Stoloniferous and erect, forming loose clumps
Sunlight & Water Needs
Full sun to partial shade, high water needs, low drought tolerance, prefers moist to wet soils with slightly acidic to neutral pH
Mowing & Maintenance
Not a turfgrass, controlled via pulling or broadleaf herbicides, high maintenance weed
Special Characteristics
Low wear tolerance, susceptible to common broadleaf herbicides, highly invasive in wet soils, excellent indicator of damp compaction
Ecological Information
Introduced species, provides minor food source for waterfowl and upland birds, aggressive weed in agricultural and turf settings