Melanthera angustifolia, commonly known as Everglades squarestem, is a herbaceous perennial plant native to the southeastern United States, particularly Florida, and parts of the Caribbean. This species is a member of the Asteraceae family, which includes daisies and sunflowers, and it plays a role in its native ecosystems. Everglades squarestem typically grows as an upright to sprawling shrub, reaching heights of 1 to 3 feet. Its stems are square in cross-section, a characteristic feature that gives rise to the common name "squarestem." The leaves are arranged oppositely along the stem and are typically lance-shaped to ovate, with serrated or toothed margins. They are usually green and can be somewhat rough to the touch. The plant produces numerous small, daisy-like flower heads, characteristic of the Asteraceae family. These flowers are typically white or cream-colored, with ray florets surrounding a central disk of tubular florets. The flowering period generally occurs from late spring through fall. Following flowering, small, dark achenes, which are the fruits of the plant, develop. These achenes are typically crowned with a pappus, a structure that aids in wind dispersal. This species is found in a variety of moist to wet habitats within its native range. It thrives in areas such as marshes, ditches, the edges of ponds and lakes, and other low-lying, poorly drained soils. Everglades squarestem is well-adapted to these wetland environments. While it is not widely cultivated, it can be grown in suitable conditions, preferring full sun to partial shade and consistently moist to wet soil. Its tolerance for wet conditions makes it a potential candidate for rain gardens or naturalistic plantings in appropriate climates. Ecologically, Melanthera angustifolia serves as a food source and habitat for various native insects and wildlife. Its flowers attract pollinators, and its seeds may be consumed by birds. While not extensively documented for ornamental, agricultural, or medicinal uses, its presence in native plant communities contributes to biodiversity. A notable characteristic of Everglades squarestem is its ability to colonize moist, disturbed areas, often forming dense stands. This growth habit can be beneficial in stabilizing soil in wetland environments. The plant's resilience and adaptation to wet conditions are key to its survival and spread in its natural habitat.