Taxonomic Studies of Diospyros (Ebenaceae) from the Malagasy Region. VII. Revision of Diospyros sect. Forbesia in Madagascar and the Comoro Islands

A recent molecular phylogenetic study revealed that Diospyros L. sect. Forbesia F. White, originally circumscribed to encompass two species from Africa and several from the Mascarene Islands (White, 1980), also includes a group of species endemic to Madagascar. The taxonomy of the Malagasy members of the section has not been examined since Perrier de la Bâthie’s 1952 treatment in the Flore de Madagascar et des Comores, and in the intervening seven decades, numerous specimens have been collected that cannot be identified based on the key provided. This revision presents a significantly updated taxonomy of Diospyros sect. Forbesia in the Malagasy region in which 18 species are recognized, 14 of which are newly described and illustrated, including one new species restricted to Mayotte Island in the Comoro archipelago. An identification key is provided as well as IUCN risk of extinction assessments, which indicate that two species are Critically Endangered, four are Endangered, and seven are Vulnerable, while one is Near Threatened and four are Least Concern. A full description is provided for each species, along with color photos; each of the new species is also illustrated with a line drawing.

Taxonomic revision of Phyllanthus (Phyllanthaceae) in Madagascar and the Comoro Islands IV: subgenus Anisonemoides section Pseudogomphidium and incertae sedis

SummaryThis paper is the fourth part of the taxonomic revision of the genus Phyllanthus in Madagascar and the Comoro Islands. Here we treat Pseudogomphidium Ralim. & Cable sect. nov. consisting of nine species that we misplaced in the subgenus Gomphidium (Baill.) G.L.Webster in our previous paper. Two species are new to science: Phyllanthus razakamalalae Ralim. & Cable, sp. nov. and P. ankirindrensis Ralim. & Cable, sp. nov. We also treat three unplaced species: P. analamerae Leandri, P. coluteoides Müll.Arg. and P. vergens Baill. An identification key, descriptions, distribution maps and IUCN Red List assessments are provided.

Correction to: Malaxideae (Orchidaceae) in Madagascar, the Mascarenes, Seychelles and Comoro Islands

The original version of this article unfortunately contains an error. Figure 6 on page 28 and Figure 64 on page 140 were missing from the published version of the papers.

Malaxideae (Orchidaceae) in Madagascar, the Mascarenes, Seychelles and Comoro Islands

Summary. The tribe Malaxideae (Orchidaceae, subfamily Epidendroideae) (sensu Pridgeon et al. 2005: 453) in Madagascar and adjacent archipelagos is revised. In this region it comprises the four genera: Liparis, Malaxis, Oberonia and Stichorkis. All of the species are described and their typification, history, identification, distribution and habitat are discussed. Conservation assessments and distribution maps are included. A checklist of the genera and species and a key to their identification are provided. Six new species: Liparis bemarahensis, L. bosseri, L. chantaliae, L. laurentii, L. magnifica and L. superclareae are described.

Age and architecture of the largest African Baobabs from Mayotte, France

The volcanic Comoro Islands, located in the Indian Ocean in between mainland Africa and Madagascar, host several thousand African baobabs (Adansonia digitata). Most of them are found in Mayotte, which currently belongs to France, as an overseas department. Baobabs constitute a reliable archive for climate change and millennial specimens were recently used as proxies for paleoclimate reconstructions in southern Africa. We report the investigation of the largest two baobabs of Mayotte, the Big baobab of Musical Plage and the largest baobab of Plage N’Gouja. The Big baobab of Musical Plage exhibits a cluster structure and consists of 5 fused stems, out of which 4 are common stems and one is a false stem. The baobab of Plage N’Gouja has an open ring-shaped structure and consists of 7 partially fused stems, out of which 3 stems are large and old, while 4 are young. Several wood samples were collected from both baobabs and analyzed via radiocarbon dating. The oldest dated sample from the baobab of Musical Plage has a radiocarbon date of 275 ± 25 BP, which corresponds to a calibrated calendar age of 365 ± 15 yr. On its turn, the oldest sample from Plage N’Gouja has a radiocarbon date of 231 ± 20 BP, corresponding to a calibrated age of 265 ± 15 yr. These results indicate that the Big baobab of Musical Plage is around 420 years old, while the baobab of Plage N’Gouja has an age close to 330 years. In present, both baobabs are in a general state of deterioration with many broken or damaged branches, and the Baobab of Plage N’Gouja has several missing stems. These observations suggest that the two baobabs are in decline and, most likely, close to the end of their life cycle.

Age and architecture of the largest African Baobabs from Mayotte, France

The volcanic Comoro Islands, located in the Indian Ocean in between mainland Africa and Madagascar, host several thousand African baobabs (Adansonia digitata). Most of them are found in Mayotte, which currently belongs to France, as an overseas department. We report the investigation of the largest two baobabs of Mayotte, the Big baobab of Musical Plage and the largest baobab of Plage N’Gouja. The Big baobab of Musical Plage exhibits a cluster structure and consists of 5 fused stems, out of which 4 are common stems and one is a false stem. The baobab of Plage N’Gouja has an open ring-shaped structure and consists of 7 partially fused stems, out of which 3 stems are large and old, while 4 are young. Several wood samples were collected from both baobabs and analyzed via radiocarbon dating. The oldest dated sample from the baobab of Musical Plage has a radiocarbon date of 275 ± 25 BP, which corresponds to a calibrated calendar age of 365 ± 15 yr. On its turn, the oldest sample from Plage N’Gouja has a radiocarbon date of 231 ± 20 BP, which translates into a calibrated age of 265 ± 15 yr. These results indicate that the Big baobab of Musical Plage is around 420 years old, while the baobab of Plage N’Gouja has an age close to 330 years. In present, both baobabs are in a general state of deterioration with many broken or damaged branches, and the Baobab of Plage N’Gouja has several missing stems. These observations suggest that the two baobabs are in decline and, most likely, close to the end of their life cycle.

Descriptive skeletal anatomy of Blommersia transmarina (Amphibia: Anura: Mantellidae) from the Comoro Islands

Mantellid frogs present an extensive adaptive radiation endemic to Madagascar and Comoros, being the subfamily Mantellinae the most morphologically and ecologically diverse. The Mantellinae present key innovative evolutionary traits linked to their unique reproductive behavior, including the presence of femoral glands and a derived vomeronasal organ. In addition, previous studies pointed to size differentiation in playing an important role in species’ dispersal capacities and shaping of their geographic ranges. Despite the high phenotypic variation observed in this clade, to date an exhaustive morphological analysis of their anatomy has still not been performed, much less in relation to internal structures. Here, we present a comprehensive skeletal description of a mantellid species, Blommersia transmarina, from the island of Mayotte in the Indian Ocean, which has potentially undergone a process of moderate gigantism compared to other Blommersia species. We describe its intraspecific skeletal variation utilizing non-destructive volume renderings from μCT-scans, and characterize the presence of sexual dimorphism and size covariation in skeletal structures. Notably, we found numerous signs of hyperossification, a novel structure for mantellids: the clavicular process, and the presence of several appendicular sesamoids. Our findings suggest that skeletal phenotypic variation in this genus may be linked to biomechanical function for reproduction and locomotion.