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| Talbotiella couteronii Sonké, M.Simo & Burgt, in Sonké, Simo-Droissart, Bidault, Ngoula et van der Burgt. 2024. |
Abstract
Background and aims – For some time now, the forests of the Sanaga basin in Cameroon have been threatened by the construction of numerous hydroelectric dams. In anticipation to this construction work, botanical surveys were carried out, resulting in the discovery of many species new to science. One of these certainly belongs to the genus Talbotiella in Leguminosae.
Material and methods – This study is based on morphological observations on herbarium specimens, through detailed examination of 28 specimens of the new tree species as well as specimens of existing species of Talbotiella.
Key results – Talbotiella couteronii is described and illustrated. The new species resembles Talbotiella batesii but has fewer leaflets, 5–10 pairs; an inflorescence usually with fewer flowers, 5–12; and flowers with longer pedicels, 10–20 mm long. Talbotiella couteronii is endemic to Cameroon, where it is restricted to the middle Sanaga basin in the Central Region and the Littoral Region. It occurs gregariously in periodically flooded riverine forests. Talbotiella couteronii is preliminarily assessed as Endangered following the IUCN Red List categories and criteria. The genus Talbotiella now consists of 10 species; of which six species are endemic to Cameroon. A comparative table summarizes the main vegetative characteristics of the 10 species. This treatment also includes an update of the description of T. bakossiensis.
Keywords: Cameroon, conservation, Endangered species, IUCN Red List assessment
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| Talbotiella couteronii. A. Flowering branch. B. Infructescence with two pods; two seeds. C. Flower with a single bract, two bracteoles, four sepals and 10 stamens. D. Stipule. E. Leaflet lower side, with two glands. F. Leaf upper side, with nine pairs of leaflets. A, E, F drawn from Sonké & Ngoula 7886 (K); B from Sonké & Ngoula 7889 (K); C from Sonké & Ngoula 7887 (K); D from Sonké & Ngoula 7888 (K). Drawing by Xander van der Burgt. |
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| Talbotiella couteronii. A. Opened flowers. B. Twig with inflorescences. C. Young leaves with stipules. D. Infructescence with two fruits. E. Immature fruits and five unripe seeds. A from Sonké & Ngoula 7888; B from Sonké & Ngoula 7886; C from Sonké & Ngoula 7895; D, E from Sonké & Ngoula 7889. |
Talbotiella couteronii Sonké, M.Simo & Burgt, sp. nov.
Diagnosis: This species closely resembles T. batesii, from which it differs by the number of bud scales (11–17 vs 3–5), narrower stipules (9–15 × 1–1.5 mm vs 13–15 × 2–2.5 mm) that are glabrous on both surfaces (vs pubescent outside along the midrib), usually fewer leaflets ((5–)6–9(–10) pairs vs 9–13 pairs), looser inflorescence with longer pedicels (10–20 mm vs 3–8.5 mm) and usually fewer flowers (5–12 vs 10–18), larger ovary (4–6 × 2–3 mm vs 1.5–3.5 × 1–1.3 mm), and larger seeds (14–21 × 10–15 × 2–3 mm vs 9–10 × 9–10 × 2–3 mm).
Etymology: This new species is named after Dr Pierre Couteron (Institut de Recherche pour le Développement, Montpellier, France) in recognition for his constant support to the first author.
Bonaventure Sonké, Murielle Simo-Droissart, Ehoarn Bidault, Fernandez Ngoula, Xander M van der Burgt. 2024. Talbotiella couteronii (Leguminosae: Detarioideae), A New gregarious Tree Species from Cameroon. Plant Ecology and Evolution. 157(3): 407-416. DOI: doi.org/10.5091/plecevo.133256
