Scientific name

Senna bicapsularis (L.) Roxb.

Synonyms

Cassia bicapsularis L.; C. augusti Harms; C. emarginataL.

Common names

Rambling cassia, moneybush, Christmas bush, yellow candlewood

Family

Fabaceae (Leguminosae): sub-family Caesalpinioideae

Origin

Northern South America, from Panama south to Venezuela and Colombia, and also the Caribbean.

Naturalised distribution (global)

Locations within which Senna bicapsularis is naturalised include coastal areas in the Galápagos Islands and New Caledonia.

Introduced, naturalised or invasive in East Africa

Senna bicapsularis is invasive in parts of Tanzania (Henderson 2002) and Uganda (A.B.R. Witt pers. obs.) and in Kenya (East African Herbarium plants database, 2011) where it has been recorded in the Rift Valley, Nairobi, Western and Nyanza, and Coast floral regions.

Habitat

Roadsides and disturbed areas, wooded grasslands, fallow land and riparian zones (banks of watercourses).

Description

Senna bicapsularis  is a shrub, often spreading, scrambling or climbing 1.5-9 m high which flowers plentifully in racemes of bright yellow flowers, with some flowers also occurring in leaf axils.

The leaves are 2.5-9 cm long, paripinnately compound. Leaf petiole eglandular, rachis with a prominent clavate or subglobose gland between the lowest pair of leaflets. Stipules very small, caduceus, up to 0.6 mm wide. Leaflets opposite in 2-4 pairs, wide rounded at apex, glabrous.

The inflorescence is a raceme, or some arrangement or racemes. The flowers are often asymmetric, 5 petals, similar to each other, yellow, or rarely white. The flowers do not produce nectar, but are insect pollinated and offer pollen as a reward to pollinators. The pedicels lack bracteoles. The stamens may be as few as 4, but usually there are 10. When 10, they occur in 3 sets. The 3 adaxial stamens are staminodial. The 4 medial stamens are smaller than the 3 abaxial stamens. The anthers are basifixed and open by two terminal pores or short slits.

The gynoecium is often deflected laterally to the right or left. This makes the flower asymmetric, but the perianth and the androecium may be asymmetrical as well. The fruit is a pod, indehiscent or tardily dehiscent.

Reproduction and dispersal

Reproduces by seed, which is released when pods open.

Similar species

Senna obtusifolia; which is distinguished by the fruit, a slender, sickle-shaped pod.

S. pendula var. glabrata is distinguished from S. bicapsularis which has 3 pairs of leaflets on each leaf and flower stalks that are 8-13 mm long, while S. pendula has 4-7 pairs of leaflets on each leaf and flower stalks that are 5mm or longer.

Economic and other uses

A useful food plant for butterfly larvae and butterfly farming and a garden ornamental. However, these uses cannot compensate for this plant's overall negative impacts.

Environmental and other impacts

Senna bicapsularis can invade native vegetation and farmland. It has been listed as a Category 3 invader in South Africa (no further planting is allowed - except with special permission - nor is trade in propagative material. Existing plants must be prevented from spreading).

Management

The precise management measures adopted for any plant invasion will depend upon factors such as the terrain, the cost and availability of labour, the severity of the infestation and the presence of other invasive species.

The best form of invasive species management is prevention. If prevention is no longer possible, it is best to treat the weed infestations when they are small to prevent them from establishing (early detection and rapid response). Controlling the weed before it seeds will reduce future problems. Control is generally best applied to the least infested areas before dense infestations are tackled. Consistent follow-up work is required for sustainable management.

The editors could not find any specific information on the control of this species.

Legislation

Not listed as a noxious weed by the state or governments in Kenya, Tanzania and Uganda.

References

International Legume Database and Information Service (ILDIS) (2005): Senna bicapsularis. http://www.ildis.org/. Accessed May 2011.

Germplasm Resources Information Network (GRIN). www.ars-grin.gov/npgs/index.html. National Germplasm Resources Laboratory, National Genetic Resources Program, Agricultural Research Service (ARS), United States Department of Agriculture (USDA), Beltsville, Maryland, USA. Accessed March 2011.

Henderson, L. (2001).  Alien weeds and invasive plants. A complete guide to declared weeds and invaders in South Africa.  Plant Protection Research Institute Handbook No. 12, 300pp. PPR, ARC South Africa.

Pacific Island Ecosystems at Risk (PIER). Senna bicapsularis (L.) Roxb., Fabaceae (Leguminosae): plant threats to Pacific ecosystems. www.hear.org/pier/species/senna_bicapsularis.htm. Institute of Pacific Islands Forestry, Hawaii, USA. Accessed March 2011.

Wikipedia contributors. "Senna bicapsularis." Wikipedia, The Free Encyclopedia. Accessed January 2011.

Editors

Agnes Lusweti, National Museums of Kenya; Emily Wabuyele, National Museums of Kenya, Paul Ssegawa, Makerere University; John Mauremootoo, BioNET-INTERNATIONAL Secretariat - UK.

Acknowledgments

This fact sheet is adapted from The Environmental Weeds of Australia by Sheldon Navie and Steve Adkins, Centre for Biological Information Technology, University of Queensland. We recognise the support from the National Museums of Kenya, Tropical Pesticides Research Institute (TPRI) - Tanzania and Makerere University, Uganda. This activity was undertaken as part of the BioNET-EAFRINET UVIMA Project (Taxonomy for Development in East Africa).

Contact

BioNET-EAFRINET Regional Coordinator: [email protected]