Three new species of Tricalysia (Rubiaceae) from Atlantic Central Africa
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Keywords

Tricalysia
Rubiaceae
Coffeeae
new species
taxonomy
Central Africa
Gabon
Equatorial Guinea
Republic of Congo

How to Cite

Lachenaud, O., Stévart, T. and Sonké, B. (2020) “Three new species of Tricalysia (Rubiaceae) from Atlantic Central Africa”, Plant Ecology and Evolution, 153(2), pp. 257-266. doi: 10.5091/plecevo.2020.1670.

Abstract

Background and aims – The genus Tricalysia A.Rich. (Rubiaceae), regarded here in the strict sense (i.e., excluding Empogona Hook.f.), includes 77 species in tropical Africa, Madagascar and the Comoros. In the current paper, three new species from Atlantic Central Africa are described and illustrated; their conservation status is also assessed.
Material and methods – This paper is based on a study of herbarium collections from BR, BRLU, K, LBV, P, WAG and YA. Normal practices of herbarium taxonomy have been applied. The conservation status assessments follow the IUCN Red List criteria.
ResultsTricalysia lophocarpa O.Lachenaud & Sonké is endemic to Gabon and is best recognised by its fruits with 8–10 narrow longitudinal ribs. Tricalysia obovata O.Lachenaud & Sonké is endemic to Equatorial Guinea (Rio Muni) and may be recognised by its obovate leaves with rounded base, glabrous stems, and sessile flowers with included style and half-exserted anthers. Tricalysia wilksii O.Lachenaud & Sonké occurs in Gabon and southwestern Republic of Congo, and may be recognised by its glabrous stems and leaves, the latter with crypt domatia, its linear calyx teeth equalling or exceeding the tube in length, and its shortly pedicellate fruits. The three species are assessed respectively as Near-threatened (T. lophocarpa), Critically Endangered (T. obovata) and Vulnerable (T. wilksii).

https://doi.org/10.5091/plecevo.2020.1670
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References

Arriola A.H., Davis A.P., Davies N.M.J., Meve U., Liede-Schumann S., Alejandro G.J.D. (2018) Using multiple plastid DNA regions to construct the first phylogenetic tree for Asian genera of Coffeeae (Ixoroideae, Rubiaceae). Botanical Journal of the Linnean Society 188(2): 132–143. https://doi.org/10.1093/botlinnean/boy059

Bridson D.M., Verdcourt B. (2003) Flora Zambesiaca vol. 5, part 3: Rubiaceae (part 3). Kew, Royal Botanic Gardens, Kew.

Davis A.P., Chester M., Maurin O., Fay M.M. (2007) Searching for relatives of Coffea (Rubiaceae Ixoroideae): Circumscription and phylogeny of Coffeeae based on plastid sequence data and morphology. American Journal of Botany 94(3): 313–329. https://doi.org/10.3732/ajb.94.3.313

Govaerts R., Ruhsam M., Andersson L., Robbrecht E., Bridson D., Davis A., Schanzer I., Sonké B. (2019) World Checklist of Rubiaceae. The Board of Trustees of the Royal Botanic Gardens, Kew. Available at http://www.kew.org/wcsp/ [accessed: 23 Jul. 2019].

Hallé N. (1970) Flore du Gabon n°17: Rubiacées (2e partie). Paris, Muséum National d’Histoire Naturelle.

IUCN (2012) IUCN Red List Categories and Criteria, version 3.1. 2nd Edition. Gland & Cambridge, IUCN Species Survival Commission.

IUCN Standards and Petitions Subcommittee (2015) Guidelines for Using the IUCN Red List Categories and Criteria. Version 11 (November 2015). Prepared by the Standards and Petitions Subcommittee. Available at http://www.iucnredlist.org/documents/RedListGuidelines.pdf. [accessed 16 Nov. 2015].

Keay R.W.J. (1958) Notes on Rubiaceae for the “Flora of West Tropical Africa” – II. Bulletin du Jardin Botanique de l’Etat à Bruxelles 28(3): 291–298. https://doi.org/10.2307/3667091

Keay R.W.J. (1963) Rubiaceae. In: Hepper F.N. (ed.) Flora of West Tropical Africa 2nd Edition, vol. 2: 148–152. London, Crown Agents for Overseas Governments and Administrations.

Lachenaud O. (2019) Révision du genre Psychotria (Rubiaceae) en Afrique occidentale et centrale. Opera Botanica Belgica vol. 17. Meise, Botanic Garden Meise.

Lachenaud O., Séné O. (2012) A new species of Multidentia (Rubiaceae) from central Africa. Plant Ecology and Evolution 145(1): 132–137. https://doi.org/10.5091/plecevo.2012.673

Lachenaud O., Zemagho L. (2015) Two new anisophyllous species of Sabicea Aubl. (Rubiaceae) from Gabon. Candollea 70(2): 219–229. https://doi.org/10.15553/c2015v702a7

Ntore S., Lachenaud O., Janssens S., Dessein S. (2010) Four new Pauridiantha species (Rubiaceae) reflect the richness of Gabon’s rainforests. Belgian Journal of Botany 142(2): 177–193. https://doi.org/10.2307/41427185

Ranarivelo-Randriamboavonjy T., Robbrecht E., Rabakonandrianina E., De Block P. (2007) Revision of the Malagasy species of the genus Tricalysia (Rubiaceae). Botanical Journal of the Linnean Society 155(1): 83–126. https://doi.org/10.1111/j.1095-8339.2007.00688.x

Robbrecht E. (1979) The African genus Tricalysia A. Rich. (Rubiaceae - Coffeeae): 1. A revision of the species of subgenus Empogona. Bulletin du Jardin Botanique National de Belgique 49(3/4): 239–360. https://doi.org/10.2307/3668089

Robbrecht E. (1982) The African genus Tricalysia A. Rich. (Rubiaceae - Coffeeae): 2. Ephedranthera, a new section of subgenus Tricalysia. Bulletin du Jardin Botanique National de Belgique 52(3/4): 311–339. https://doi.org/10.2307/3667886

Robbrecht E. (1983) The African genus Tricalysia A. Rich. (Rubiaceae): 3. Probletostemon revised as a section of subgenus Tricalysia. Bulletin du Jardin Botanique National de Belgique 53(3/4): 299–320. https://doi.org/10.2307/3667793

Robbrecht E. (1987) The African genus Tricalysia A. Rich. (Rubiaceae): 4. A revision of the species of sectio Tricalysia and sectio Rosea. Bulletin du Jardin Botanique National de Belgique 57(1/2): 39–208. https://doi.org/10.2307/3668317

Robbrecht E. (1988a) Tricalysia. In: Bridson D., Verdcourt B. (eds) Flora of Tropical East Africa: Rubiaceae (Part 2): 540–566. Kew, Royal Botanic Gardens, Kew.

Robbrecht E. (1988b) Tropical woody Rubiaceae. Characteristics, features and progressions. Contribution to a new subfamilial classification. Opera Botanica Belgica vol. 1. Meise, National Botanic Garden of Belgium.

Sonké B., Cheek M., Nambu D.M.., Robbrecht E. (2002a) A new species of Tricalysia A. Rich. (Rubiaceae) from western Cameroon. Kew Bulletin 57(3): 681–686. https://doi.org/10.2307/4110999

Sonké B., Kenfack D., Robbrecht E. (2002b) A new species of the Tricalysia atherura group (Rubiaceae) from southwestern Cameroon. Adansonia 24(2): 173–177.

Sonké B., Lachenaud O. (2016) Two new species of Oxyanthus DC. (Rubiaceae) from Central Africa. Candollea 71(2): 173–180. https://doi.org/10.15553/c2016v712a2

Sonké B., Bidault E., Droissart V. (2015) Synopsis of the genus Massularia (Rubiaceae) with a new species from Central Africa. Phytotaxa 203(3): 263–270. https://doi.org/10.11646/phytotaxa.203.3.5

Taedoumg H., Sonké B., Hamon P., De Block P. (2017) Craterispermum capitatum and C. gabonicum (Rubiaceae): two new species from the Lower Guinean and Congolian Domains. Phyto­Keys 83: 103–118. https://doi.org/10.3897/phytokeys.83.13623

Thiers B. (continuously updated) Index Herbariorum: A global directory of public herbaria and associated staff, New York Botanical Garden’s Virtual Herbarium. Available at http://sweetgum.nybg.org/ih/ [accessed 18 Oct. 2018].

Tosh J., Davis A.P., Dessein S., De Block P., Huysmans S., Fay M.F., Smets E., Robbrecht E. (2009) Phylogeny of Tricalysia (Rubiaceae) and its relationships with allied genera based on plastid DNA data: resurrection of the genus Empogona. Annals of the Missouri Botanical Garden 96(1): 194–213. https://doi.org/10.3417/2006202

White F. (1979) The Guineo-Congolian Region and its relationship to other phytochoria. Bulletin du Jardin Botanique National de Belgique 49(1/2): 11–55. https://doi.org/10.2307/3667815

White F. (1983) The Vegetation of Africa. A descriptive memoir to accompany the Unesco/AETFAT/UNSO, vegetation map of Africa. Natural Resources Research UNESCO 20. Paris, UNESCO.

White F. (1993) The AETFAT chorological classification of Africa: history, methods and applications. Bulletin du Jardin Botanique National de Belgique 62(1/4): 225–281. https://doi.org/10.2307/3668279

Zemagho L., Lachenaud O., Dessein S., Liede-Schumann S., Sonké B. (2014) Two new Sabicea Aubl. (Rubiaceae) species from West Central Africa: Sabicea bullata and S. urniformis. Phytotaxa 173(4): 285–292. https://doi.org/10.11646/phytotaxa.173.4.3

Zemagho L., Liede-Schumann S., Lachenaud O., Dessein S., Sonké B. (2017) Taxonomic revision of Sabicea subgenus Anisophyllae (Ixoroideae, Rubiaceae) from Tropical Africa, with four new species. Phytotaxa 293(1): 1–68. https://doi.org/10.11646/phytotaxa.293.1.1

Zemagho, Lachenaud O., Sonké B. (2018) Four new species of Sabicea (Rubiaceae) from tropical Africa, with additional notes on the genus. Candollea 73(2): 277–293. https://doi.org/10.15553/c2018v732a12

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