American sicklepod
Senna obtusifolia (L.) H.S.Irwin & Barneby
Senna obtusifolia (L.) H.S.Irwin & Barneby is a subshrub in the legume family, Fabaceae, commonly known as American sicklepod. It is native to the Americas but has become naturalized in many tropical and subtropical regions around the world, including parts of Asia, Africa, and Oceania. This species is often considered a noxious weed due to its aggressive growth and ability to colonize disturbed areas. It is distinguished by its 6-leaflet leaves, yellow flowers, and linear legumes. The plant has a long history of taxonomic confusion, particularly with Senna tora, and has been the subject of several nomenclatural revisions.
Description
Senna obtusifolia is a subshrub with glabrous, inermous branches. The leaves are paripinnate, with 6 leaflets arranged oppositely, and obovate in shape. The venation is brochidodromous, and there is no translucid punctuation. The inflorescence is an axillary raceme, with zygomorphic, yellow flowers. Each flower has a calyx of 5 sepals and a corolla of 5 petals. The androecium is dialystaminous and heterodinamous, with poricidal anthers. The ovary is superior, stipitate, and pluriovulate. The fruit is a legume, sessile, linear, and cylindrical, with a straight margin and a glabrous, brown epicarp. The seeds are trapezoidal, flat, with a brown coat and a basal hilum.
Habitat
Senna obtusifolia is typically found in disturbed and open habitats, including roadsides, fields, and wastelands. It thrives in a wide range of environments, from semi-arid regions to moist tropical forests. The species is particularly common in the Americas, with a documented presence in various regions of Colombia, Brazil, and other countries. It is also found in conservation units such as the Parque Nacional Natural Macuira and Parque Nacional Natural Tayrona. The plant is well-adapted to a variety of soil types and can tolerate both dry and humid conditions.
Cultivation
While not typically cultivated for agricultural purposes, Senna obtusifolia can be grown in controlled environments for study or as a model plant in botanical research. It requires well-drained soil and full sun to partial shade. The plant is relatively drought-tolerant once established but benefits from regular watering during dry periods. Propagation is typically done through seeds, which should be sown in warm, moist conditions. Due to its aggressive growth and weedy nature, care should be taken to prevent its spread in cultivated areas.
Uses
Senna obtusifolia has been used in traditional medicine, particularly in parts of Asia and South America, where it is valued for its laxative properties. The plant contains anthraquinone glycosides, which are known to stimulate bowel movements. However, due to its toxic potential in high doses, its use is often limited to controlled applications. The plant is also used as a forage species in some regions, although its high tannin content can make it unpalatable to livestock. In addition, it is sometimes used in phytoremediation projects due to its ability to accumulate heavy metals from the soil.
Other common names
Java-beanSicklepodcoffee-weedAmerican sicklepodsicklepod sennaSlimming Plantarsenic weedblunt-leaved sennaChinese sennacoffeeweedfoetid sennasickle senna
Distribution
Complejo Humedales Hato Corozal. Cienaga Zapatosa · Amazonas, Antioquia, Atlántico, Bolívar, Boyacá, Caldas, Caquetá, Casanare, Cauca, Cesar, Chocó, Córdoba, Cundinamarca, Huila, La Guajira, Magdalena, Meta, Norte de Santander, Risaralda, Santander, Sucre, Tolima, Valle del Cauca · BR · Subregiones: Norte, Zona central · CO · Parque Nacional Natural Macuira Vía Parque Isla de Salamanca | Parque Nacional Natural Tayrona | Parque Nacional Natural Sierra de la Macarena | Parque Nacional Natural Tinigua | Parque Nacional Natural Los Katíos · MM · VU · ZA · HR · SA · Belgium · Flemish Region · WS · PW · SB · AI · France · The Netherlands · Great Britain · KH · BW · ET · Gavilán Finca Gavilán Sade · KM · FM · VN · MU · SG · Barrancabermeja | Bolívar | Cimitarra | Puerto Parra | Simacota | Tona
Synonyms
Cassia obtusifoliaSenna toroidesCassia toroidesCassia tora var. obtusifoliaCassia tora var. humilisCassia toroidesCassia rogeoniiSenna tora var. obtusifoliaCassia tora var. humilisEmelista obtusifolia
