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| Vepris teva Cheek, in Langat, Kami & Cheek, 2022. DOI: 10.7717/peerj.13926 |
Abstract
Continuing a survey of the chemistry of species of the largely continental African genus Vepris, we investigate a species previously referred to as Vepris sp. 1 of Congo. From the leaves of Vepris sp. 1 we report six compounds. The compounds were three furoquinoline alkaloids, kokusaginine (1), maculine (2), and flindersiamine (3), two acridone alkaloids, arborinine (4) and 1-hydroxy-3-methoxy-10-methylacridone (5), and the triterpenoid, ß-amyrin (6). Compounds 1–4 are commonly isolated from other Vepris species, compound 5 has been reported before once, from Malagasy Vepris pilosa, while this is the first report of ß-amyrin from Vepris. This combination of compounds has never before been reported from any species of Vepris. We test the hypothesis that Vepris sp. 1 is new to science and formally describe it as Vepris teva, unique in the genus in that the trifoliolate leaves are subsessile, with the median petiolule far exceeding the petiole in length. Similar fleshy-leathery four-locular syncarpous fruits are otherwise only known in the genus in Vepris glaberrima (formerly the monotypic genus Oriciopsis Engl.), a potential sister species, but requiring further investigation to confirm this phylogenetic position. We briefly characterise the unusual and poorly documented Atlantic coast equatorial ecosystem, where Vepris teva is restricted to evergreen thicket on white sand, unusual in a genus usually confined to evergreen forest. This endemic-rich ecosystem with a unique amphibian as well as plants, extends along the coastline from the mouth of the Congo River to southern Rio Muni, a distance of about 1,000 km, traversing five countries. We map and illustrate Vepris teva and assess its extinction risk as Endangered (EN B1ab(iii)+B2ab(iii)) using the IUCN, 2012 standard. Only three locations are known, and threats include port and oil refinery construction and associated activities, with only one protected location, the Jane Goodall Institute’s Tchimpounga Reserve. Initial evidence indicates that the seeds of Vepris teva are dispersed by chimpanzees, previously unreported in the genus.
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| Vepris teva Cheek sp. nov. Shrub with mature (yellow) and immature (green) fruits. Note the sessile leaves. From Mpandzou et al., 1198 (IEC, K). Photo by M. Cheek. |
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| Vepris teva Cheek sp. nov. (A) Habit, fruiting stem; (B) detail of leaflet blade showing oil gland dots and nervation, lower surface of blade in foreground; (C) detail of male inflorescence; (D) male flower, side view; (E) as (D), two petals removed to show stamens; (F) pistil of male flower, four-lobed, viewed from above; (G) male flower, two petals and three stamens removed to show pistil; (H) mature fruit, side view (seed on right); (I) fruit, plan view; (J) fruit, transverse section, showing four locules, three aborted and one with seed. (A and H–J) from Mpandzou et al., 1198, (B and G) from Kami, T. et al 1356; (C–F) from Kami, T. et al., 1227. Drawn by Juliet Williamson, CC-BY-NC-ND. |
Vepris teva Cheek sp. nov.
Diagnosis: differs from all known trifoliolate species of Vepris in the median petiolule far exceeding the petiole in length (usually by a factor of 2–4 times) on reproductive stems, especially near the stem apex (vs petiole exceeding petiolule in length in all other species). Most similar to Vepris glaberrima (Engl.) J.B.Hall ex D.J. Harris in the soft, leathery-fleshy, four-loculed, and slightly lobed, subverrucate syncarpous fruit, differing in the inflorescences exceeding the petiole in length (vs shorter than the petioles), the secondary nerves (10–)11–16(–18) on each side of the midrib (vs 20–30), the leaflet apices shortly rounded-acuminate (vs long, acutely acuminate) and other characters shown in Table 1 above.
Etymology. Named for Teva Kami, lead collector of the type specimen, who played a key role in the discovery of this species and further research upon it concerning interactions with chimpanzees (see below).
Moses K. Langat, Teva Kami and Martin Cheek. 2022. Chemistry, Taxonomy and Ecology of the potentially Chimpanzee-dispersed Vepris teva sp.nov. (Rutaceae) endangered in Coastal Thicket in the Congo Republic. PeerJ. 10:e13926. DOI: 10.7717/peerj.13926
