hogweed is a poisonous and actively spreading plant on the ground

flower plant summer green nature hogweed giant wild beautiful heracleum floral large botany leaf flora bloom white dangerous weed blossom blooming danger season natural grass toxic herb burn outdoor wildflower stem invasive field closeup meadow poison foliage harmful spring mantegazzianum poisonous background ecology petal growth allergen deadly actively spreading ground umbellate cow parsnip flowering day ripening seeds