Alternanthera philoxeroides is a perennial herbaceous plant native to South America. It is commonly referred to as alligator weed, pigweed or washer woman. The plant has gained notoriety for its invasive tendencies, spreading quickly and crowding out native vegetation. In addition to its negative ecological impact, Alternanthera philoxeroides has also been used for medicinal purposes in some cultures. Other synonyms for the plant include Alternanthera triandra, Alternanthera pungens, Alternanthera ficoidea, and Achyranthes philoxeroides. Despite its problematic nature, some gardeners appreciate the plant for its attractive red and green foliage, which adds a splash of color to landscaping projects.