Ludwigia octovalvis (Jacq.) P.H.Raven

  • Authority

    Acevedo-Rodríguez, Pedro & collaborators. 1996. Flora of St. John, U.S. Virgin Islands. Mem. New York Bot. Gard. 78: 1-581.

  • Family

    Onagraceae

  • Scientific Name

    Ludwigia octovalvis (Jacq.) P.H.Raven

  • Description

    Species Description - Erect herb or subshrub, 0.3-1 m tall; twigs puberulent, slightly angled, becoming glabrous and cylindrical with age. Leaves alternate; blades 2.5-11 x 0.7-2.2 cm, narrow-elliptic to linear, chartaceous, puberulent, usually with cystoliths, the apex obtuse or acute, the base attenuate, the margins entire, ciliate; petioles 3-5 mm long. Flowers solitary in leaf axils; pedicel 1-1.5 mm long, with a pair of opposite bracteoles at base of hypanthium. Hypanthium club-shaped, 4-angled, 3-3.5 mm long, crowned by 4 green, ovate to lanceolate sepals, 5.5-10 mm long; petals 4, yellow, 7-12 mm long, with a few cystoliths, spreading, obovate with a shallowly emarginate apex; stamens 8, the epipetalous ones shorter, the filaments 1-4 mm long; disk pubescent; ovary 4- locular with numerous ovules, the style 1.5-3.5 mm long, the stigma nearly globose, 4-lobed. Capsule cylindrical, 2.7-4.5 cm long, turning from green to brown, with 8 longitudinal ribs, irregularly dehiscent, crowned by the persistent spreading sepals. Seeds numerous, rounded, brown, ca. 0.6 mm long.

    Distribution and Ecology - A common weed of wet ditches along roadsides. Road to Bordeaux (A 1890). Also on St. Croix, St. Thomas, and Tortola; widespread throughout the tropics.