Popcorn Senna
African Senna

Senna didymobotrya

African Senna, Senna didymobotrya, Kenya, photo © by Michael Plagens

Observed at the perimeter of pastureland near Eldoret, Kenya. January 2012.

FLOWERS: The spikes of bright yellow and brown pea-flowers at roadsides are conspicuous. Flower buds are brown-purple before opening.

flower detail of African Senna, photo © Michael Plagens SHRUB: The upper parts of the plant are herbaceous supported by woody stems below. Most plant are one to two meters tall.

LEAVES: Leaves are compound, smooth, and bright green. Each leaf has a dozen or more pairs of oblong-elyptic leaflets, plus a pair of stipules at the base of the petiole. When crushed or rubbed the leaves emit a strong, disagreeable odor. For some this odor suggests another common name, Peanut Butter Senna.

RANGE: This native plant is most abundant in agricultural areas because of disturbed soil and because grazing animals tend to avoid it.

FRUIT: An erect, flattened bean pod with many seeds.

UNARMED. No thorns.

Stipules, nectar glands (extra-floral nectaries) and Myrmicine ants of African Senna, Senna didymobotrya, Kenya, photo © by Michael Plagens

This enlarged view shows the leaf bases and stem of a plant found near Iten, Kenya, July 2014. The large dark green stipules clasp the stem but also have glandular tissue (extra-floral nectaries) that secretes a sugary substance that is highly attractive to ants. In this case the ants belong to the Myrmicinae subfamily. These ants repel other insects that migh damage the plant and can sting animals that might browse the already distasteful foliage. The ants and the plant have a survival alliance!

Fabaceae -- Bean Family -- Caesalpinioideae - Senna Sub-Family

More Information:

Kenya Natural History

Copyright Michael J. Plagens, Created on 21 September 2012,
updated 13 January 2015.