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Senna occidentalis
Fabaceae FAMILY Least Concern

Senna occidentalis

Senna occidentalis

Edibility
2/5
Medicinal
3/5

Safety & Hazards

The foliage is poisonous and generally avoided by livestock[1]. The seeds contain compounds that damage the liver, vascular system, heart and lungs of domestic livestock[2].

Cultivation Details

HabitAnnual/Perennial
Growth—

Coffee senna has a wide native range from the subtropics of S. America through to southern N. America and the Caribbean. It grows mainly at lower elevations. It favours moister areas in the tropics, in Puerto Rico it grows in areas where the mean annual rainfall is within the range 1,000 - 2,200mm[1]. Prefers a deep, well-drained, moderately fertile sandy loam and a position in full sun[3]. Originally native of the Americas, the plant is widely cultivated through the tropics and subtropics and is commonly naturalized in many areas[4]. While coffee senna can be a weed of cultivated fields and plantations, it is principally a problem because it accumulates in heavily grazed pastures[1]. The plant flowers throughout the year in non-seasonal climates[4]. The plant has a characteristic foetid odour when bruised or crushed[5, 2]. There are conflicting reports on whether or not this tree has a symbiotic relationship with certain soil bacteria, so it is unclear as to whether this tree fixes atmospheric nitrogen[6].

Propagation

Like many species within the family Fabaceae, once they have been dried for storage the seeds of this species may benefit from scarification before sowing in order to speed up and improve germination. This can usually be done by pouring a small amount of nearly boiling water on the seeds (being careful not to cook them!) and then soaking them for 12 - 24 hours in warm water. By this time they should have imbibed moisture and swollen - if they have not, then carefully make a nick in the seedcoat (being careful not to damage the embryo) and soak for a further 12 hours before sowing[PFAF]. Some 95% of scarified seeds sown in potting mix germinated between 5 and 36 days after sowing[1]. Cite as: Tropical Plants Database, Ken Fern. tropical.theferns.info. 2026-02-20. <tropical.theferns.info/viewtropical.php?id=Senna+occidentalis>

Pollinators

Insects

References

  1. [1]Wildland Shrubs of the United States and its Territories: Thamnic Descriptions — Francis J.K. (Editor) · USDA; Forest Service International Institute of Tropical Forestr · 2000 · http://www.fs.fed.us/global/iitf/wildland_shrubs.htm ↩︎An excellent series of papers, in PDF format, from various authors giving quite detailed information on a range of shrubs growing in the United States and its Territories. It can be downloaded from the Internet.
  2. [2]IUCN Red List of Threatened Species — http://www.iucnredlist.org/ ↩︎A list of plants under threat and facing possible extinction, usually with brief details of the threats and information on habitat.
  3. [3]The New RHS Dictionary of Gardening. 1992. — Huxley. A. · MacMillan Press · 1992 · ISBN 0-333-47494-5 ↩︎Excellent and very comprehensive, though it contains a number of silly mistakes. Readable yet also very detailed.
  4. [4]Flora Malesiana Series 1 — Various · Nationaal Herbarium Nederiand, Universiteit Leiden branch · http://www.archive.org ↩︎A massive treatment of the plants of the Malaysian Archipelago. Much of it has been made available to download from the Internet
  5. [5]Flora of Guatemala — Standley P.C. & J. A. Steyermark · 1946 - 1976 · http://www.archive.org/ ↩︎A superb reference, though somewhat dated. Gives lots of plant uses as well as information on plant habit and habitat. The entire flora (13 volumes) can now be downloaded from http://www.archive.org/
  6. [6]Nodulation Plants in GRIN Taxonomy — United States Department of Agriculture · http://www.ars-grin.gov/~sbmljw/cgi-bin/taxnodul.pl?language=en ↩︎An online database listing plants that have either positive or negative reports on root and stem nodulation with nitrogen-fixing bacteria.
  7. [7]Dictionary of Economic Plants. — Uphof. J. C. Th. · Weinheim · 1959 · ISBN - ↩︎An excellent and very comprehensive guide but it only gives very short descriptions of the uses without any details of how to utilize the plants. Not for the casual reader.
  8. [8]Medicinal Plants of the Guianas — DeFilipps, R. A.; Maina, S. L.; & Crepin, J. · Smithsonian Museum · http://botany.si.edu/bdg/medicinal/index.html ↩︎A down-loadable PDF document of a book in pre-publication awaiting illustration. An excellent, if rather terse, guide to the traditional medicinal uses of the plants of the region
  9. [9]Cornucopia II — Facciola. S. · Kampong Publications, California. · 1998 · ISBN 0-9628087-2-5 ↩︎The second edition of an excellent guide to the edible uses of plants, though it does not give any details of cultivation etc.
  10. [10]Edible Wild Plants of Tanzania — Ruffo, C.K.: Birnie, A. & Tengnas, B. · Regional Land Management Unit; Nairobi. · 2002 · ISBN 9966-896-60-0 ↩︎A very well presented, simple guide to growing and utilizing wild food plants in Tanzania, with line drawings of each plant, a description, habitat and range, non-food as well as food uses, plus basic information on growing the plants.
  11. [PFAF]Plants for a Future — pfaf.org ↩︎