Rhexia

Rhexia is a genus of flowering plants in the family Melastomataceae. Rhexia species are commonly called “meadow beauty” and 11 to 13 species of Rhexia have been recognized depending on different taxonomic treatments.[1][2][3]

Unlike other members of the same family showing pantropical distribution, Rhexia is mainly distributed in temperate region of southeastern part of North America; from Nova Scotia to Florida and the West Indies (Cuba, Hispaniola, and Puerto Rico) and west to eastern Texas.[4] The species of Rhexia are frequently found in wet meadows, coastal plain marshes, sandy wetlands and lake edges, pine woods, and road-side swales. Most Rhexia species successfully establish on open areas disturbed by recurrent burning or reclamation.[5]

Rhexia species are herbaceous perennials. Opposite leaves are simple, ovate to lanceolate and have the typical acrodromous venation (prominent arcuate nerves) characteristic of the Melastomataceae. Stems have four faces; one set is broader and convex, the other set is narrower, concave. Flowers are actinomorphic (radially symmetrical), 2–3 cm in diameter, pink-purple to white, (yellow in R. lutea), petals 4, sepals 4, stamens 8. Bright yellow anthers are long and curved counterclockwise. Seeds are cochleate (noncochleate in R. alifanus).[5]

The Melastomataceae is a large tropical plant family characterized by buzz pollination. Like other members of the family, it appears that flowers of Rhexia species are buzz pollinated. For example, Rhexia virginica is buzz pollinated by bumblebees and shows two representative features of the buzz pollination syndrome; bright yellow anthers and flower color changes after anthesis.[6]