Slender Threeseed Mercury (Acalypha gracilens) vs. One-Seeded Mercury (Acalypha monococca)
Updated October 8th, 2026These two species are easily confused in their small range of overlap from southeast MO and southern IL southwest to east TX. They are reliably distinguished by count of seeds per bract, and they have subtle differences in leaf margin serrations and leaf tips that can ID some plants as A. gracilens. A. monococca ranges farther northwest and prefers slightly sunnier, drier conditions, higher soil pH, and tends to occur on persistently-open sites. A. gracilens ranges farther east, tolerates more acidic soil, and is found on slightly richer sites on disturbed ground.
