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| Afzelia corallina A.Bianchi, S.Orsenigo & Baldesi, in Bianchi, Baldesi, Calzoni, Delledonne, Focaia, Luke, Khamis, Tomasi et Orsenigo, 2026. |
Abstract
Afzelia corallina A.Bianchi, S.Orsenigo & Baldesi (Fabaceae: Detarioideae) is described from the coral rag forests of the Tondooni Peninsula in the Ngezi–Vumawimbi Forest Reserve on Pemba Island, Zanzibar, Tanzania. Morphologically distinct from all known members of the genus, this large, emergent tree shows the closest affinities to Afzelia quanzensis but differs in several vegetative and floral characters, including its falcate leaflets, highly branched terminal inflorescences, petal colour, the colour of stamens, and the number of extra staminodes. The species is currently known only from a restricted coastal limestone habitat, indicating a micro-endemic distribution. An updated diagnostic key to East African Afzelia species is provided. This discovery highlights the botanical uniqueness and conservation importance of Pemba’s remaining forest ecosystems.
Key words: Afzelieae, Detarioideae, new species, Ngezi, taxonomy, Vumawimbi
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| Afzelia corallina. a. Flower close-up showing two rudimentary subulate petals; b. Single flower; c. Inflorescence. Pictures by: Andrea Bianchi. |
Afzelia corallina A.Bianchi, S.Orsenigo & Baldesi sp. nov.
Diagnosis. This species is similar to Afzelia quanzensis but can be distinguished by paniculate inflorescence (vs. racemose or one-forked inflorescence), number of flowers per inflorescence (up to 150 vs. 4–12), colour of the large petal (white and red, with a white median stripe vs. entirely green outside and red inside, occasionally mottled with white or greenish-white), the shape of small petals (subulate vs. clavate), the colour of stamen and staminodes that are crimson red in A. corallina and green, often with a red base, in A. quanzensis. Moreover, A. corallina shows a bigger style (40–50 mm vs 25 mm) and ovary (7 × 2.2–2.7 vs. 3.5 × 1.5 mm) compared to A. quanzensis. Finally, pods are thinly woody and 1–4 seeded (vs. thickly woody and 5–13 seeded in A. quanzensis), and seeds have much smaller aril (4–5 vs. 8–13 mm long) (Table 1).
Etymology. The epithet corallina (from the Latin ‘corallium’, coral) refers to this species’ habit of growing on coral rag, a rubbly limestone composed of ancient coral reef material. Furthermore, the colourful and dense inflorescence may resemble a coral head, as does the red marking on the large petal.
Andrea Bianchi, Giacomo Baldesi, Daniela Calzoni, Massimo Delledonne, Riccardo Focaia, Quentin Luke, Khamis A. Khamis, Laura Tomasi and Simone Orsenigo. 2026. Afzelia corallina (Fabaceae), A New micro-endemic Tree from Pemba Island, Zanzibar, Tanzania. PhytoKeys. 273: 55-69. DOI: doi.org/10.3897/phytokeys.273.186903 [9 Apr 2026]
