@article {102, title = {Yam genomics supports West Africa as a major cradle of crop domestication}, journal = {SCIENCE ADVANCES}, volume = {5}, year = {2019}, month = {1 May 2019}, pages = {1-8}, chapter = {1}, abstract = {

While there has been progress in our understanding of the origin and history of agriculture in sub-Saharan Africa,
a unified perspective is still lacking on where and how major crops were domesticated in the region. Here, we
investigated the domestication of African yam (Dioscorea rotundata), a key crop in early African agriculture. Using
whole-genome resequencing and statistical models, we show that cultivated yam was domesticated from a forest
species. We infer that the expansion of African yam agriculture started in the Niger River basin. This result, alongside
with the origins of African rice and pearl millet, supports the hypothesis that the vicinity of the Niger River
was a major cradle of African agriculture.

}, doi = {10.1126/sciadv.aaw1947}, author = {Nora Scarcelli and Philippe Cubry and Roland Akakpo and Anne-C{\'e}line Thuillet and Jude Obidiegwu and Mohamed N. Baco and Emmanuel Otoo and Bonaventure Sonk{\'e} and Alexandre Dansi and Gustave Djedatin and C{\'e}dric Mariac and Marie Couderc and Sandrine Causse and Karine Alix and H{\^a}na Cha{\"\i}r and Olivier Fran{\c c}ois and Yves Vigouroux} } @article {101, title = {Taxonomy and phylogenetics of Cuviera (Rubiaceae{\textendash}Vanguerieae) and reinstatement of Globulostylis with the description of three new species}, journal = {Botanical Journal of Linnean Society}, volume = {173}, year = {2013}, pages = {407-441}, chapter = {407}, abstract = {

Generic circumscriptions in tribe Vanguerieae (Rubiaceae) have been under discussion for a long time. Recent
molecular studies, while providing new insights, have not yet solved all the problems. In this study, the taxonomy
and phylogenetics of the genus Cuviera s.l. are investigated. On the basis of molecular and morphological evidence,
Cuviera is restricted to a group of ten West and Central African species. Globulostylis, previously included in
Cuviera, is reinstated as a distinct genus, with eight species from Central Africa. Both genera are revised; the
latter includes three new species (G. dewildeana, G. rammelooana and G. robbrechtiana) and two new combinations
(G. leniochlamys and G. uncinula). The close relationship of Cuviera s.s. and Globulostylis to Vangueriella is
shown. Six aberrant species (most from East Africa) are excluded from Cuviera, but further work is needed before
they can be confidently assigned to other genera.

}, author = {Brecht Verstraete and Olivier Lachenaud and Erik Smets and S. Dessein and Bonaventure Sonk{\'e}} } @article {99, title = {Morphology, molecular phylogenetics and biogeography of Impatiens akomensis (Balsaminaceae), a new species from Cameroon.}, journal = {Plant Ecology and Evolution}, volume = {148}, year = {2015}, pages = {397-408}, chapter = {397}, abstract = {

Background and aims \– A recent field expedition in the Campo-Ma\’an/Akom II region in Cameroon
resulted in the collection of a previously unknown Impatiens species, which resembles Impatiens macroptera
and Impatiens pseudomacroptera. This study aims to describe and infer the evolutionary history of this
novelty by using phylogenetics, biogeographic inference and dating estimation analyses.
Methods \– The new species was subject to a palynological, molecular phylogenetic and biogeographical
analysis. In addition, a thorough morphological comparison with its closely related species was conducted.
Key results \– Morphological comparison and molecular phylogenetics corroborate its status as a new
species, which is given the name Impatiens akomensis. Molecular data, based on ImpDEF1, ImpDEF2 and
ITS indicate that Impatiens akomensis is most closely related to the Cameroonian I. macroptera, whereas
the lineage towards I. macroptera and the novelty is sister to the Gabonese I. pseudomacroptera. Impatiens
akomensis differs from I. macroptera and I. pseudomacroptera in having very strongly asymmetric white
flowers, much thicker leaves, a narrowly elliptic leaf shape and a serrulate leaf margin, smaller lateral
united petals (23.1\–24.2 mm) and larger bracts (12\–20 mm). The new species qualifies for endangered
status under IUCN criteria B2 and probably B1.
Conclusions \– Dating analyses in combination with biogeographic inference, and ecological and
environmental interpretation of the novelty and its closely related species allows us to infer the putative
evolutionary history of Impatiens akomensis

}, author = {S.B. Janssens and Bonaventure Sonk{\'e} and O. Lachenaud and B. Lemaire and M. Simo-Droissart and E. Smets} } @article {98, title = {Le genre Oxyanthus (Rubiaceae) en Afrique de l{\textquoteright}Ouest: description d{\textquoteright}une nouvelle esp{\`e}ce.}, journal = {Candollea}, volume = {70}, year = {2015}, pages = {241-247}, chapter = {241}, abstract = {

A new species, Oxyanthus andjigae Sonk\é \& O. Lachenaud (Rubiaceae), from Ivory Coast and Sierra Leone, is described
and illustrated. It is closely related to Oxyanthus racemosus (Schumach. \& Thonn.) Keay and Oxyanthus setosus Keay, and
was previously confused with the latter species; however, it differs from both in the longer corolla tube (18-19.5 cm vs
(7-)11-15.5 cm) and the longer hairs on the twigs (1.5-2 mm long vs. \≤ 1 mm in Oxyanthus setosus and \≤ 0.5 mm in
Oxyanthus racemosus). From Oxyanthus setosus it is also separated by the distribution, the latter species occuring from
Nigeria to Gabon. The species is assessed as \“Endangered\” following IUCN Categories and Criteria. A new identification
key to West African species of Oxyanthus DC. is presented; Oxyanthus oliganthus K. Schum. is newly reported from
C\ôte d\’Ivoire and Ghana.

}, doi = {dx.doi.org/10.15553/c2015v702a10.}, author = {Olivier Lachenaud and Bonaventure Sonk{\'e}} } @article {96, title = {Morphometrics and molecular phylogenetics of Angraecum section Dolabrifolia (Orchidaceae, Angraecinae).}, journal = {Plant Syst Evol.}, volume = {302}, year = {2016}, pages = {1027-1045}, chapter = {1027}, abstract = {

Background and aims \– Recent molecular studies suggest the polyphyly of Angraecum and the
unnaturalness of some of its sections, as exemplified by sect. Pectinaria, which has species in two wellseparated
clades, one in Madagascar and the other in continental Africa. However, species delimitation
among the five continental African members remained problematic due to morphological variability. In
preparation for the taxonomic revision of this group, we used morphological and molecular data to re-assess
the circumscription of each species, and to evaluate their monophyly and relationships to one another.
Methods \– A total of 59 alcohol-preserved specimens were used to perform multivariate analyses on 37
morphological characters. DNA sequences from one nuclear (ITS-1) and five plastid regions (matK, rps16,
trnL\–F, trnC\–petN and ycf1) were analyzed using Parsimony and Bayesian methods.
Key results \– The morphometric study revealed five distinct morphospecies that correspond to the concepts
of the currently recognized species. Angraecum doratophyllum and A. subulatum are the most distinct
morphologically, whereas A. atlanticum, A. gabonense and A. pungens are most similar to one another.
Phylogenetic analyses using a combined data set of the six markers yielded highly resolved, congruent
trees with strong branch support. The polyphyly of A. sect. Pectinaria is confirmed, with continental
African members appearing to be most closely related to sect. Dolabrifolia, found exclusively in Africa.
The multiple accessions of A. doratophyllum, A. gabonense, A. pungens and A. subulatum each formed a
well-supported clade. Parsimony and Bayesian analyses placed A. atlanticum and A. pungens in a subclade
within which samples of A. pungens were nested but those of A. atlanticum formed a grade. These two
species can be easily distinguished morphologically by leaf dimensions and flower length, but broader
sampling in continental Africa is needed to test whether individuals recognized as A. atlanticum might
represent two distinct taxa.

}, keywords = {Angraecoid orchid, Angraecum, Bayesian analyses, continental Africa, molecular phylogeny, monophyly, morphometric analyses, parsimony, sect. Pectinaria.}, doi = {10.1007/s00606-016-1315-5.}, author = {Murielle Simo-Droissart and Bonaventure Sonk{\'e} and Vincent Droissart and Claire Micheneau and Porter P. Lowry II and Olivier J. Hardy and Gregory M. Plunkett and Tariq St{\'e}vart} } @article {95, title = {Synoptic revision of the genus Cyrtorchis Schltr. (Angraecinae, Orchidaceae) in Central Africa, with the description of a new species restricted to submontane vegetation.}, journal = {Phytotaxa}, volume = {267}, year = {2016}, pages = {165-186}, chapter = {165}, abstract = {

As a preliminary step to the taxonomic revision of the genus Cyrtorchis, a synoptic revision of the species occurring in Central
Africa was undertaken. Based on a detailed examination of 1,039 herbarium specimens, including nomenclatural types,
we have recognized 14 species in Central Africa (one of which is divided into two subspecies), including one new species
that the study brought to light, described here as Cyrtorchis submontana. The new species closely resembles C. guillaumetii
and C. brownii in general aspect, but differs from them in having thinner, small elliptic leaves and shorter, fewer-flowered,
more lax inflorescences with shorter bracts. The species is restricted to submontane vegetation of Central Africa and is assessed
as Endangered following the IUCN Red List Categories and Criteria. Cyrtorchis latibracteata and C. subcylindrifolia
are lectotypified, and the latter is placed as a synonym under C. henriquesiana. Many new records are reported, and for each
taxon the distribution, habitat and ecology are given. An identification key for the Central African taxa is also provided.

}, doi = {dx.doi.org/10.11646/phytotaxa.267.3.1.}, author = {Laura Azandi and Tariq St{\'e}vart and Bonaventure Sonk{\'e} and Murielle Simo-Droissart and Marie-Louise Avana and Vincent Droissart} } @article {94, title = {Phylogenetics and diversification history of African rattans (Calamoideae, Ancistrophyllinae).}, year = {2016}, abstract = {

Even though African rain forests display high levels of local species diversity and endemism, their lower
continental species diversity when compared with the Neotropics and Asia is paradoxical. This disparity is
mainly thought to be linked to either important extinction events during the Pleistocene or at the Eocene\–
Oligocene boundary. African rattans or climbing palms are one of the most diverse clades of palms in Africa,
representing one-third of all known species. Here, we reconstruct the phylogeny and temporal evolution of
African rattans (Arecaceae: Calamoideae: Lepidocaryeae: Ancistrophyllinae) to test the two main hypotheses of
palm evolution in Africa. We constructed a near-complete, dated species-level phylogenetic tree for subtribe
Ancistrophyllinae using plastid and nuclear markers. The generic relationships between Ancistrophyllinae were
fully resolved and species-level relationships are well to weakly supported. Ancistrophyllinae diversified during
the Eocene with most species originating during the late Miocene after 10 Mya. This result is in agreement with
several other studies suggesting a pre\–Pleistocene origin of the extant African flora. Ancistrophyllinae display an
anti-sigmoidal lineage-through-time plot with a moderate overall extinction fraction. Our simulations suggest
important roles for an ancient extinction event at the Oligocene\–Eocene boundary. In contrast, the hypothesis of
an important extinction event in palms during the late Pliocene at 3 Mya is not supported. We suggest that the
evolutionary history of African rattans has undergone a constant diversification rate punctuated by one or
several important extinction events during the first part of the Cenozoic with most species diversity accumulating
during the late Miocene and Pliocene.

}, doi = {10.1111/boj.12454.}, author = {Adama Faye and Jean-Christophe Pintaud and William J. Baker Fls and Yves Vigouroux and Bonaventure Sonk{\'e} and Thomas L. P. Couvreur} } @article {93, title = {Phylogenetics of tribe Sabiceeae (Ixoroideae, Rubiaceae) revisited, with a new subgeneric classification for Sabicea.}, journal = {Botanical Journal of Linnean Society}, volume = {182}, year = {2016}, pages = {551-580}, chapter = {551}, abstract = {

Tribe Sabiceeae (Ixoroideae, Rubiaceae) has undergone recent taxonomical changes with the incorporation of the
related genera Ecpoma, Pseudosabicea and Stipularia into the type genus Sabicea. We use phylogenetic analysis
and morphological data to verify the relationships among members of the tribe, including the most
comprehensive taxon sampling of the tribe to date with 74 of 145 species. Sequence data from the nuclear
internal transcribed spacer (ITS) and three plastid markers (petD, rps16, trnT\–F) were used to infer relationships
among the members of the tribe. Individual analyses using maximum likelihood, parsimony and Bayesian
approaches reveal several supported clades: the former genus Stipularia is resolved as a monophyletic unit, but
Ecpoma is monophyletic only if Sabicea urbaniana and Sabicea xanthotricha are included (corresponding to
Sabicea subgenus Stipulariopsis sensu Wernham). Pseudosabicea is biphyletic, with one clade corresponding to
section Anisophyllae of Halle (1964) and the other one to the other sections (Floribundae and Sphaericae) of the
genus. Eleven morphological characteristics were recorded for all species studied and seven have been mapped
onto the phylogenetic tree to study their evolution in the group and assess their value for the classification of
Sabicea s.l. Finally, our study shows that a combination of diagnostic characteristics should be used to
differentiate each group and we propose to recognise four subgenera in Sabicea.

}, doi = {10.1111/boj.12475.}, author = {Lise Zemagho and Sigrid Liede-Schumann and Bonaventure Sonk{\'e} and Steven Janssens and Olivier Lachenaud and Brecht Verstraete and Steven Dessein} } @article {92, title = {A taxonomic revision of Angraecum section Dolabrifolia (Orchidaceae, Angraecinae), with the description of a new species from Gabon.}, journal = {Phytotaxa}, volume = {280}, year = {2016}, pages = {81{\textendash}115}, chapter = {81}, abstract = {

Despite a paucity of material available from continental Africa, previous morphological and molecular phylogenetic studies
have suggested that Angraecum, the largest genus of the angraecoid orchids, is polyphyletic. A recent study based on
broad sampling from the region confirmed the monophyly of section Dolabrifolia and a clear delimitation of four of its five
members, one of which represents a new species. Based on these results, a comprehensive taxonomic revision of Angraecum
sect. Dolabrifolia is presented here. It includes an identification key and a detailed description of each species, along with
color photographs, distribution maps, information on habitat and phenology, and a preliminary risk of extinction assessment
according to the IUCN Red List categories and criteria. Species richness in the section is highest in Atlantic Central Africa
and around the Albertine Rift. The new species, A. biteaui, is described and illustrated with line drawings. It most closely
resembles A. aporoides in general aspect but differs in both foliar and floral characters, and is only known from lowland
forests in Gabon.

}, doi = {doi.org/10.11646/phytotaxa.280.2.1}, author = {Murielle Simo-Droissart and Bonaventure Sonk{\'e} and Vincent Droissart and Daniel Geerinck{\textdagger} and Porter P. Lowry II and Tariq St{\'e}vart} } @article {87, title = {Guinea yam (Dioscorea spp., Dioscoreaceae) wild relatives identified using whole plastome phylogenetic analyses. }, year = {2018}, abstract = {

The genus Dioscorea (Dioscoreaceae) contains several economically important species for human consumption,
medical and pharmaceutical uses. The phylogeny of this genus is not yet fully resolved. As a result, the relationships between
cultivated yams and their wild relatives are not well understood and this negatively affects the understanding of the evolution
of cultivated yams. Here, we reconstructed the phylogenetic relationships of the main African cultivated species with all West
African species in order to better circumscribe the crop wild relatives of African yams. Complete plastomes of 57 individuals
representing all 17 known Dioscorea species from West Africa were reconstructed. Tree topologies generated using maximum
parsimony and maximum likelihood approaches were highly congruent. Six monophyletic groups were obtained. All the
species were distinct except within the cultivated clade, where it was not possible to separate the two main cultivated species
(D. cayenensis, D. rotundata) from their closest West African wild relatives (D. abyssinica, D. praehensilis, D. sagittifolia).
Dioscorea baya formed a monophyletic group closely related to the cultivated clade. We therefore suggest it is included within
the yam crop\–wild relative complex.

}, doi = {doi.org/10.12705/675.4}, author = {acqueline Magw{\'e}-Tindo and J, Jan J. Wieringa and Bonaventure Sonk{\'e} and Louis Zapfack and Yves Vigouroux and Thomas L.P. Couvreur and Nora Scarcelli} } @article {86, title = {Two new species of Raphia (Palmae/Arecaceae) from Cameroon and Gabon}, journal = {PhytoKeys}, volume = {111}, year = {2018}, pages = {17-30}, chapter = {17}, abstract = {

Raphia (Arecaceae, Calamoideae) is the most diverse genus of African palms with around 20 species.
Two new species from Cameroon and Gabon, Raphia gabonica Mogue, Sonk\é \& Couvreur, sp. nov. and
Raphia zamiana Mogue, Sonk\é \& Couvreur, sp. nov. are described and illustrated. Their affinities are
discussed and the conservation status of each species is assessed. For both species, distribution maps are
provided. Raphia gabonica is restricted to two small populations from central Gabon, where it occurs on
hillsides on tierra firme soil, and close to small streams. Its preliminary IUCN status is Endangered, being
amongst the five most threatened palm species in Africa. Raphia gabonica potentially belongs to the moniliform
section. Raphia zamiana is largely distributed from south Cameroon to south Gabon and is very
common. It is also a multi-used palm, from which wine, grubs and construction material are extracted and
sold. It generally occurs in large stands in a wide range of ecosystems such as swamps, coastal forests on
partially inundated sandy soils and inundated savannahs. Its large stature, hard to access habitat (swamps)
and abundant presence might have discouraged botanists to collect it until now. Raphia zamiana belongs
to the taxonomically complex raphiate section.

}, doi = {doi: 10.3897/phytokeys.111.27175 http://phytokeys.pensoft.net}, author = {Suzanne Mogue Kamga and Raoul Niangadouma and Fred W. Stauffer and Bonaventure Sonk{\'e} and Thomas L.P. Couvreur} } @article {84, title = {Complete plastome sequences of 14 African yam species (Dioscorea spp.).}, year = {2019}, author = {Jacqueline Magw{\'e}-Tindo and Jan J. Wieringa and Bonaventure Sonk{\'e} and Louis Zapfack and Yves Vigouroux and Thomas L. P. Couvreur and Nora Scarcelli} } @article {83, title = {Mine versus Wild: a plant conservation checklist of the rich Iron-Ore Ngovayang Massif Area (South Cameroon)}, journal = {Plant Ecology and Evolution}, volume = {152}, year = {2019}, pages = {8-29}, chapter = {8}, abstract = {

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Background and aims \– The rapid expansion of human activities in South Cameroon, particularly mining in mountainous areas, threatens this region\’s exceptional biodiversity. To comprehend the effects of land-use change on plant diversity and identify conservation priorities, we aim at providing a first comprehensive plant checklist of the Ngovayang Massif, focusing on the two richest plant families, Orchidaceae and Rubiaceae.

Location \– The Ngovayang Massif Area (NMA) is located in the South Region of Cameroon. It is covered by lowland and submontane rainforest (100 to 1110 m elevation).

Methods \– We compiled a dataset of 6116 georeferenced herbarium specimens, of which 2787 belong to Rubiaceae and Orchidaceae. We used rarefaction methods to explore sampling and diversity patterns, and investigated the altitudinal distribution of rare and/or threatened taxa.

Key results \– The NMA, which houses about 1500 vascular plant taxa, is the richest documented area for Rubiaceae in Atlantic Central Africa (ACA) and the fifth for Orchidaceae, with respectively 281 and 111 taxa. Among these taxa, 178 (45\%) are endemic to ACA and 67 (17\%) are considered globally threatened according to IUCN categories and criteria. We show that higher elevation areas (\> 750 m), which are also the main areas targeted for mining, are the richest in endangered and/or rare species. Three new records for Cameroon are reported here.

Conclusion \– The NMA represents an Important Plant Area of Cameroon as confirmed by its exceptional plant diversity (\> 20\% of the total Flora of Cameroon), by the concentration of many threatened and/or restricted range species (10 taxa are strict endemics of the massif) as well as by the threat on rare habitats (i.e. the submontane vegetation above ~750 m elevation). A management plan involving in situ and ex situ conservation actions is urgently needed to reduce the potential threats of future mining activities.

}, keywords = {Biodiversity, endangered species, Important Plant Area, iron and gold exploitation, new records, orchids, Rubiaceae, submontane forest}, doi = {doi.org/10.5091/plecevo.2019.1547}, author = {Vincent Droissart and Olivier Lachenaud and Gilles Dauby and Steven Dessein and Gysl{\`e}ne Kamdem and Charlemagne Nguembou K. and Murielle Simo-Droissart and Tariq St{\'e}vart and Hermann Taedoumg and Bonaventure Sonk{\'e}} } @article {82, title = {Four new species of Sabicea (Rubiaceae) from tropical Africa, with additional notes on the genus. }, journal = {Candollea}, volume = {73}, year = {2018}, month = {23 November 2018}, pages = {277-293}, chapter = {277}, abstract = {

Four new species of Sabicea (Rubiaceae) from tropical Africa are described and illustrated: S. desseinii from Cameroon, Gabon and Equatorial Guinea, S. ezangae from Gabon, S. jongkindii from Liberia and Ghana, and S. uniflora from Gabon. Their affinities are discussed, and the conservation status of each species is assessed. Sabicea speciosissima K.Schum. is excluded from the genus and synonymised with Rothmannia octomera (Hook.) Fagerl. Three other species are sunk into synonymy: Sabicea gigantea Wernham with S. dewevrei De Wild., S. arachnoidea Hutch. \& Dalziel with S. discolor Stapf, and S. neglecta Hepper with S. speciosa K.Schum.

}, keywords = {Africa, Cameroon, Equatorial Guinea, Gabon, Ghana, Liberia, new species, Rubiaceae, Sabicea, taxonomy}, author = {Lise Zemagho and Olivier Lachenaud and Bonaventure Sonk{\'e}} } @book {81, title = {Taxonomic revision of Sabicea subgenus Anisophyllae (Ixoroideae, Rubiaceae) from Tropical Africa, with four new species. Phytotaxa 293(1): 68 p. doi.org/10.11646/phytotaxa.293.1. Magnolia Press, Auckland, New Zealand.}, year = {2017}, abstract = {

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A taxonomic revision of Sabicea subgenus Anisophyllae (Rubiaceae), a group restricted to Central and East Africa, is presented here. This work, based on a study of herbarium specimens and field observations in Cameroon and Gabon, includes a survey of the morphological features of the group, a key to the species, descriptions of all the taxa, and IUCN conservation status assessments. Fifteen species are recognised, four of which are described as new (Sabicea mapiana, S. ndjoleensis, S. parmentierae, S. sciaphilantha), while three former varieties are raised to species rank (S. crystallina, S. jacfelicis, S. tersifolia) and one species previously sunk into synonymy is restored (S. bequaertii). Two new infraspecific taxa are also described, Sabicea crystallina subsp. engongensis and S. sciaphilantha subsp. hirsuta. The group has its center of diversity in Gabon, where 10 of the 15 species occur, three of them being endemic to the country.

}, author = {Lise Zemagho and Sigrid Liede-Schumann and Olivier Lachenaud and Steven Dessein and Bonaventure Sonk{\'e}} }