Nematostylis Hook. f. (Rubiaceae) is a genus of semi-succulent shrubs endemic to Madagascar, mostly found growing on rocky outcrops in the Northern, Central, and Southern Highlands. This paper provides a revision of the genus in which three species are recognized: N. anthophylla (A. Rich. ex DC.) Baill. and the newly described N. citriflora Kainul. and N. incarnata Kainul. An identification key of the genus is presented, as well as a distribution map, field pictures, line drawings, and species risk of extinction assessments. A neotype is designated for N. anthophylla and a lectotype for N. loranthoides Hook. f. Résumé KAINULAINEN, K. (2023). Révision taxonomique du genre Nematostylis (Rubiaceae) endémique de Madagascar, avec la description de deux nouvelles espèces. Candollea 78: 177 -188. En anglais, résumés anglais et français.

Hopkins, H.C.F. & J. Wajer (2023). Variation in the colour and shape of capitula in Parkia bicolor (Leguminosae) illustrated by two watercolours from southern Nigeria painted by Dorothy Amaury Talbot (1871–1916). Candollea 78: 125–138. In English, English abstract. DOI: http://dx.doi.org/10.15553/c2023v782a3 As currently circumscribed, Parkia bicolor A. Chev. (Leguminosae, Caesalpinioideae, mimosoid clade) includes all the African material of this genus in which the red or reddish capitula have a well-developed fringe formed by long staminodial filaments that extend from the basal sterile flowers; the fertile flowers in each capitulum form a large apical ball, which is either spherical or ellipsoidal. Capitula of different shapes and colours in this widely circumscribed species are illustrated in two watercolour paintings at the Natural History Museum (NMH) in London, both labelled “Mr. & Mrs. P. A. Talbot 1912, 1913. Southern Nigeria”. Each painting appears to be a composite based on more than one collection. The Talbots' plant specimens (c. 4,000 numbers) and paintings and sketches (c. 1,000) at the NHM have sometimes been attributed to either Percy Amaury Talbot entirely, or to both Percy and his wife Dorothy together. However, sources including correspondence between the Talbots and botanists at the NHM make clear that Dorothy was responsible for all the artwork and for the majority of their herbarium collections. Descriptions and photographs in addition to Dorothy's artwork suggest that variation in the shape of the capitula is potentially of greater taxonomic significance than differences in colour, but we refrain from drawing any taxonomic conclusions until a comprehensive morphological analysis of P. bicolor has been carried out. Received on May 13, 2023. Accepted on August 16, 2023. First published online on September 13, 2023.

Andriamiarisoa, R.L., M.N. Rabarimanarivo & S. Porembski (2023). Une nouvelle espèce de Linderniella (Linderniaceae) des inselbergs granitiques du centre de Madagascar. Candollea 78: 11–15. En anglais, résumés anglais et français. Une plante rupicole, reviviscente, spécialistes des inselbergs est nouvellement décrite et illustrée. Linderniella porembskii Andriamiar. & Rabarim. (Linderniaceae) est restreinte aux inselbergs granitiques du centre de Madagascar, dans la Région d'Amoron'i Mania. Elle se distingue des autres espèces malgaches du genre par son port herbacé avec des tiges richement ramifiées et touffues, décombantes et dressées, des plantes glabres à glabrescentes et sa capsule obovoïde-acuminée. Une description détaillée de l'espèce est fournie, accompagnée d'illustrations et d'une clé d'identification des espèces malgaches du genre. La nouvelle espèce est considérée comme “En danger” selon les Catégories de la Liste rouge de l'UICN.

Stone, R.D. (2022). Traitement révisé de Memecylon section Buxifolia (Melastomataceae) à Madagascar. Candollea 77: 173–191. En anglais, résumés anglais et français. Memecylon sect. Buxifolia R.D. Stone (Melastomataceae, Olisbeoideae) est un groupe d'arbustes et de petits arbres forestiers distribué de l'Afrique de l'Est tropicale (Kenya et Tanzanie) à l'Est de l'Afrique du Sud avec une occurrence disjointe dans l'ouest et le nord de Madagascar. Dans un traitement précédent, trois espèces de cette section étaient reconnues endémiques de Madagascar: M. amplifolium R.D. Stone, M. buxifolium Blume (= M. perrieri Danguy) et M. multinode Jacq.-Fél. Dans ce travail, six nouvelles espèces malgaches appartenant à cette section sont décrites et illustrées: M. ambilobense R.D. Stone, M. angustatum R.D. Stone, M. leptophyllum R.D. Stone, M. minutifolium R.D. Stone, M. oblanceolatum R.D. Stone et M. reductum R.D. Stone. Avec ces révisions, la flore de Madagascar comprend actuellement neuf espèces dans Memecylon sect. Buxifolia. Nous en proposons un traitement taxonomique, avec une clef d'identification. Pour chaque espèce, le statut de conservation est évalué selon les Catégories et Critères de la Liste rouge de l'UICN.

Robert, Y., H. Thomas, J.M. Tamon & G. Rouhan (2021). Discovery in La Reunion Island of Elaphoglossum multisquamosum (Dryopteridaceae), known so far as endemic to Madagascar. Candollea 76: 99–104. In French, English and French abstracts.A species of the fern genus Elaphoglossum Schott ex J. Sm. (Dryopteridaceae) has been discovered in La Réunion. It is ascribed to Elaphoglossum multisquamosum Bonap., described and known so far as endemic to Madagascar. Taking advantage of this new record, Elaphoglossum multisquamosum is reinstated as a species distinct from the Malagasy endemic Elaphoglossum poolii (Baker) Christ. Morphologically close to Elaphoglossum poolii that is often observed in sympatry in Madagascar, Elaphoglossum multisquamosum has often been treated as a variety of Elaphoglossum poolii or even placed in synonymy of the latter species. We provide a novel, fully detailed description of Elaphoglossum multisquamosum, all critical characters supporting it as distinct from Elaphoglossum poolii, and a comparative map of distribution for the two species in Madagascar and La Réunion. Finally, the name Elaphoglossum multisquamosum is lectotypified.

The identity of the long-overlooked Ronabea morindoides and Patabea tenuiflora, synonymous with a species of Appunia (Rubiaceae). Candollea 76: 83-92. In English, English abstract. The identity of Ronabea morindoides A. Rich. has long been unclear and is here investigated. Two sheets of original material corresponding to this name are deposited in the General Herbarium of the National Museum of Natural History of Paris (P), and represent a mixed collection; one part of this material corresponds better with the description of this taxon and is more unambiguously identifiable, and is here designated the lectotype. With this typification, Ronabea morindoides represents a species of Appunia Hook. f. The identity of Patabea tenuiflora DC. has also remained uncertain since its description and is here clarified by studying the holotype in the Candolle Herbarium (G-DC); this is an additional synonym of R. morindoides. Taxonomic review of this group in the Guianas also finds that Ronabea morindoides is an older name for Appunia brachycalyx (Bremek.) Steyerm. and Appunia surinamensis Bremek. (Morindeae). Therefore, the new combination Appunia morindoides (A. Rich.) Delprete, C.M. Taylor & T. McDowell is here published. Received: August 15, 2020; Accepted: December 1, 2020; First published online: February 1, 2021

Atalahy, A.M., F. Rakotonasolo, M. Rabarimanarivo, H.L.T. Ranarijaona & S.G. Razafimandimbison (2021). New species of the genus Pyrostria (Rubiaceae, Vanguerieae) from Madagascar. Candollea 76: 1–12. In French, English and French abstracts.In the course of a taxonomic revision of the genus Pyrostria Comm. ex Juss. (Rubiaceae, Vanguerieae) in Madagascar, we describe five new species endemic from the Island: Pyrostria ambohitantelensis Atalahy, Rakotonas. & Razafim., Pyrostria ambrensis Atalahy, Rakotonas. & Razafim., Pyrostria betsomangensis Atalahy, Rakotonas. & Razafim., Pyrostria coriacea Atalahy, Rakotonas. & Razafim. and Pyrostria longicorollata Atalahy, Rakotonas. & Razafim. Each new species is provided with line drawings, a discussion on its morphological affinities and a risk of extinction assessment based on the IUCN Red List criteria.

Beentje, H. & O. Lachenaud (2020). The inclusion of Akeassia in Grangea (Asteraceae) and description of a new species from Gabon: Grangea ogoouensis. Candollea 75: 311 – 319. In English, English and French abstracts.The discovery of a new Gabonese species of Asteraceae leads us to reevaluate the distinction between the genera Grangea Adans. and Akeassia J.-P. Lebrun & Stork. The differences between the two genera proving unreliable, Akeassia is included in Grangea, resulting in the new combination Grangea grangeoides (J.-P. Lebrun & Stork) Beentje & O. Lachenaud. A key to the ten species of Grangea is presented, as well as complete morphological descriptions for the three species occurring in Gabon: Grangea grangeoides, Grangea maderaspatana (L.) Desf., and and the new species Grangea ogoouensis O. Lachenaud & Beentje. The new species differs from Grangea grangeoides by its pinnatifid lower leaves and more numerous pappus-bristles, and from Grangea maderaspatana by its free pappus bristles and smaller phyllaries. It appears to be endemic to Gabon, and its conservation status is assessed as “Vulnerable”.