Read the dictionary definition of horsemint. All definitions for this word.
1. a coarse Old World wild water mint having long leaves and spikelike clusters of flowers; naturalized in the eastern United States
2. tall erect perennial or annual having lanceolate leaves and heads of purple-spotted creamy flowers; many subspecies grown from eastern to southwestern United States and in Mexico
3. an annual horsemint of central and western United States and northern Mexico