Delaware officials say the saturation of wet weather on the Delmarva peninsula has contributed to the increased growth of buttercups.
Despite the flowers' gentle, yellow hue, WMDT-TV reports that the plants are poisonous, and can cause serious health issues for horses and other livestock.
The Delaware Department of Agriculture says accidental consumption while grazing could cause skin twitching, paralysis and pain. Delaware Deputy State Veterinarian Karen Lopez says ingestion could even prove fatal.
Officials advise using weed killers or removing the plants by hand.