Vitellaria paradoxa

Why are the seeds of this species difficult? This species has recalcitrant seeds, which have a high critical moisture content and will rapidly lose viability if they are dried.

Vitellaria paradoxa (Image: E. Vaes, RBG Kew)

Seed Storage

This species has Recalcitrant seeds which cannot be dried without causing a decline in viability. Do not place the seeds under sub-zero temperatures as they will suffer from freezing damage due to their high moisture content.

Researchers have found that the seeds have an initial seed moisture content of around 41%, and that the minimum safe moisture content after drying is around 30% mc (equivalent to 95-98% equilibrium relative humidity). Longevity in storage can be extended by keeping the seeds either fully or partially hydrated.

Germination Requirements

Germinate these seeds on sand or agar at 36ºC. Germination will not occur at temperatures below 11ºC.

The seeds of this species do not display dormancy.

Seed Morphology

The fruits (4-5 cm) are ellipsoidally-shaped berries, with a fleshy pulp and usually containing just one seed. The ovoid seeds (2.5-5 cm) are shiny and dark brown with a white scar on one side.

When ripe, the fruit epicarp turns green/yellow in colour.

See images of this species at VIRBOGA (The Virtual Botanic Garden) and the Digital Atlas of Economic Plants.

Taxonomy

Family: SAPOTACEAE

Accepted name: Vitellaria paradoxa C.F.Gaerter

Synonyms: Lucuma paradoxa (C.F.Gaertn.) A.DC., Butyrospermum mangifolium (Pierre ex A.Chev.) A.Chev., Butyrospermum paradoxum (C.F.Gaertn.) Hepper

Common name: shea-butter, karité

References and Links

Gaméné, C.S., Pritchard, H.W. and Daws, M.I. (2004). Effects of desiccation and storage on Vitellaria paradoxa seed viability. In M. Sacandé, D. Joker, M. Dulloo and K. Thompsen (eds) Comparative Storage Biology of Tropical Tree Seeds. IPGRI, Rome, Italy.
Janick, J. and Paull, R.E. (eds) (2008). The Encyclopedia of Fruit and Nuts. CAB International, UK.
Purseglove, J.W. (1968). Tropical Crops: dicotyledons. Longman Group Ltd., UK.

AFPD (African Flowering Plants Database) - Conservatoire et Jardin Botaniques de la Ville de Genève, Switzerland, and South African National Biodiversity Institute, Pretoria, RSA: Vitellaria paradoxa.
Forest & Landscape Denmark - University of Copenhagen, Denmark: seed leaflet on Vitellaria paradoxa.
PROTAbase (Plant Resources of Tropical Africa) - Wageningen, Netherlands: Vitellaria paradoxa.
SID (Seed Information Database) - Royal Botanic Gardens, Kew, UK: Vitellaria paradoxa.
Tropicos - Missouri Botanical Garden, USA: Vitellaria paradoxa.