Ongokea is a genus of flowering plants, with one species Ongokea gore (Boleko).[1] In the APG IV system, the genus is placed in the family Olacaceae.[3][1] Other sources place it in the segregate family Aptandraceae.[4]

Ongokea
Scientific classification Edit this classification
Kingdom: Plantae
Clade: Tracheophytes
Clade: Angiosperms
Clade: Eudicots
Order: Santalales
Family: Olacaceae
Genus: Ongokea
Pierre[1]
Species:
O. gore
Binomial name
Ongokea gore
(Hua) Pierre[1]
Synonyms[1][2]

Genus synonymy

  • Schoepfianthus Engl. ex De Wild.

Species synonymy

  • Aptandra gore Hua
  • Ongokea kamerunensis Engl.
  • Ongokea klaineana Pierre
  • Schoepfianthus zenkeri Engl. ex De Wild.

Its native range is Western Tropical Africa to Angola,[1] and is notable for the seeds of its edible fruits containing an industrially-useful oil that can undergo explosive polymerization reactions at elevated temperatures.[5] This oil is curious for being rich in diacetylenic and hydroxy-diacetylenic fatty acids, primarily isanic and bolekic acid - that is, instead of a typical single-bonded fatty acid backbone, these acids contain multiple (thermally unstable) triple bonds.[6]

Description edit

Ongokea gore is a medium to large size tree that can reach 40 m tall with a diameter than reach 1.2 m and often has basal root swellings.[7] It has a fairly open crown that is usually in the upper canopy of the forest. The bark is thick, dark brown, grey or black in color, it is commonly smooth but sometimes scaly and generally fissured and lenticellate.[7] The slash is yellowish in color and scented.[7]

The leave are mid shade green in color and the petiole is 6-10 mm long.[7] The leaflets are elliptic to ovate in shape, about 4-8 cm long and 2-5 cm wide with a base that is cuneate to rounded and an apex that is acuminate. The inflorescence is axillary and paniculate, the flowers are green in color. [7] The fruit is sometimes called Isano by locals, it is drupe like, up to 4 cm in diameter and 1 seeded.[8]

Ecology edit

Oribatid mites is a dominant inhabitant within suspended soil that has accumulated on branches of the Ongokea gore tree in the rain forest of Gabon, other inhabitants include tectocepheus mites.[9]

Distribution edit

Occurs in West and Central Africa, in evergreen and semi-deciduous forest environments.[7]

Chemistry edit

Oil obtained from the seeds of Ongokea gore contains the fatty acid group, dia-acetylenic and has isanic, isanolic, hydroxy acetylenic and bolekic acids.[8]

Uses edit

The seed oil and stem bark extracts are sometimes used as part of a purgative decoction.[10]

References edit

  1. ^ a b c d e f "Ongokea". Plants of the World Online. Royal Botanic Gardens, Kew. Retrieved 16 February 2024.
  2. ^ "Ongokea gore". Plants of the World Online. Royal Botanic Gardens, Kew. Retrieved 16 February 2024.
  3. ^ Angiosperm Phylogeny Group (2016). "An update of the Angiosperm Phylogeny Group classification for the orders and families of flowering plants: APG IV". Botanical Journal of the Linnean Society. 181 (1): 1–20. doi:10.1111/boj.12385.
  4. ^ Stevens, P.F. "Aptandraceae". Angiosperm Phylogeny Website. Retrieved 2021-07-18.
  5. ^ Vegetable Oils: Tropical Resources of Africa 14. 2007. p. 127. ISBN 9789057821912.
  6. ^ "Fatty Acids: Acetylenic and Allenic - crepenynic - plants, animals, mosses - composition and biochemistry".
  7. ^ a b c d e f Voorhoeve, A.G. Liberian high forest trees : a systematic botanical study of the 75 most important or frequent high forest trees, with reference to numerous related species (PhD thesis). Wageningen University.
  8. ^ a b Vossen, H. A. M. van der, ed. (2007). Vegetable oils. Plant resources of tropical Africa. Wageningen: PROTA. p. 128. ISBN 978-90-5782-192-9.
  9. ^ Basset, Yves, ed. (2003). "Fauna of suspended soils in an Ongokea gore tree in Gabon". Arthropods of tropical forests: spatio-temporal dynamics and resource use in the canopy (1. publ ed.). Cambridge: Cambridge Univ. Press. ISBN 978-0-521-82000-4.
  10. ^ Jerz, Gerold; Waibel, Reiner; Achenbach, Hans (2005). "Cyclohexanoid protoflavanones from the stem-bark and roots of Ongokea gore☆". Phytochemistry. 66 (14): 1698–1706. doi:10.1016/j.phytochem.2005.04.031.