Common: Narrowleaf Sumpweed
South Central US
- W Texas northeastward to central Arkansas
- Central Arkansas southward to SW Louisiana
- SW Louisiana westward to S and W Texas
- Local populations in NE Oklahoma, SE Kansas, and NW Florida
Narrowleaf marsh elder, also called narrowleaf sumpweed, is found in disturbed areas that are seasonally moist. It may form extensive mats that may reach 4 feet in height. The leaves are about 1 to 2 inches long and narrow, giving the species its name. The rather inconspicuous greenish flowers, occurring from early September through October, are located in the leaf axils above the long, narrow bracts. Although the flowers are wind-pollinated, this species is of rather modest importance in causing allergy.