Non-grass Plant (Sicklepod / Coffee Senna / Coffeeweed)
Senna obtusifolia (syn. Cassia obtusifolia) · Summer Annual, Broadleaf Herb (C3 Dicot)
Grass Family
Fabaceae (Legume family), Subfamily Caesalpinioideae
Grass Category
Agricultural Weed / Forage Weed / Native Pioneer Plant
Variety / Cultivar
Wild type / Naturally occurring species
Hardiness Zones
USDA Zones 7-11; dies back at first frost; seeds persist in soil for many years.
About This Grass
An upright, herbaceous plant reaching 1-6 feet. Features alternate, pinnately compound leaves and distinct curved seed pods (sickle-shaped). It is not a grass, but a broadleaf legume frequently found in pastures.
Blade Characteristics
Leaves are compound with 2-3 pairs of leaflets; leaflets are obovate (teardrop-shaped), rounded at the tip, and lack parallel venation characteristic of grasses.
Root System
Strong, deep taproot; lacks fibrous grass-like roots; difficult to pull once established.
Growing Information
Origin Region
Native to the Americas (Southeastern US to South America); pantropical distribution
Growth Habit
Erect, branching herb with a woody base; Taprooted (No rhizomes or stolons)
Sunlight & Water Needs
Full sun; drought-tolerant; thrives in disturbed Soils, sandy loam, and agricultural fields.
Mowing & Maintenance
Resistant to mowing; can regrow from the base if cut early; typically managed with broadleaf herbicides or pulling.
Special Characteristics
Produces yellow flowers; seeds are toxic to livestock (cattle, horses) causing muscle degeneration (myopathy).
Ecological Information
Native pioneer species; fixes nitrogen; seeds are consumed by some birds but generally considered a nuisance in managed turf and pastures.