Contribution to the study of Orchidaceae from Madagascar. XXXVIII. Two new species and one new combination for the genus Pectinariella Szlach. Mytnik & Grochocka in Madagascar

Before passing away, Jean Bosser (23rd of December 1922-6th of December 2013) worked on describing two species of Angraecopsis Kraenzl. The manuscript has never been submitted for publication, we thus undertook to complete his work using specimens we collected in Eastern Madagascar. The study of these specimens allowed us to determine that the two species belong to the genus Pectinariella Szlach. Mytnik & Grochocka and that one of these two species was not a novelty but corresponded rather to Pectinariella pterophylla (H. Perrier) Verlynde & Ramandimbisoa, comb. nov. for which we redefine morphological delimitation. We publish the second species under Pectinariella edmundi Bosser ex Verlynde & Ramandimbisoa, sp. nov. Finally, Pectinariella scroticalcar Verlynde & Ramandimbisoa, sp. nov. a third species, endemic to the eastern forests of Madagascar and possessing novel floral characteristics for the genus, is described. For each species, we provide conservation status, illustrations as well as ecological and distribution notes. A determination key of the six species of Pectinariella found in Madagascar is given.SCOPUS: ar.jinfo:eu-repo/semantics/publishe

Diversity and distribution of Orchidaceae in one of the world's most threatened plant hotspots (Madagascar)

Introduction. In recent decades, Madagascar has become one of the most important plant hotspots in the world. The country's remaining forests and vegetation are disappearing at an alarming rate, while dozens of new species are discovered each year. Amongst the plant families that have long been studied, Orchidaceae appear as one of the most charismatic, diverse and of high conservation concern. Based on a reviewed, comprehensive herbarium dataset, we have compiled a curated checklist of all orchid species occurring in Madagascar. Based on this complete dataset, we then compiled sampling effort, species diversity distribution and some general statistics on their ecology and IUCN conservation status.Methods. We compiled and standardised a global dataset using five public databases as the main data sources, supplemented by the most recent publications. The database contains ~ 10,000 geolocated records collected between 1816 and 2021. We used GIS software and rarefaction methods to examine sampling and diversity patterns.Results. According to our dataset, there are currently 913 orchid species collected in Madagascar, of which 759 orchid species (83.1%) are endemic. Doubling the sampling effort could lead to the discovery of around 100 more species, bringing the total estimated number of orchid species in Madagascar to between 986 and 1048. About one-third (297 species) of all orchid species are known only by type specimens (189 species) or have not been collected in Madagascar for more than 50 years (214 species). Although the raw data show that the Andasibe-Moramanga area would have the highest orchid species concentration, our analysis of the data, adjusted for bias, shows that the centres of orchid diversity in Madagascar are in the Tsaratanàna Strict Nature Reserve and the Ranomafana National Park. Life-form statistics show that 55.0% of orchid species are strict epiphytes. The main flowering period of orchids in Madagascar is between November and March. To date, 84% of the 226 Malagasy orchid species listed in the IUCN Red List are threatened with extinction (CR, EN or VU).Conclusion. Despite geographically uneven coverage, the biodiversity of Malagasy orchids appears to be already well documented. We provide maps corrected for sampling bias that indicate priority areas for future surveys. Upcoming efforts should also focus on rediscovery and conservation of rare and/or threatened species and ensure that the protected area network is well aligned with the distribution of priority species for conservation. Finally, the conservation status of 75% of the orchid species found in Madagascar is not yet known and the inclusion of these species must be a top priority in the coming years

Supplementary material 2 from: Droissart V, Verlynde S, Ramandimbisoa B, Andriamahefarivo L, Stévart T (2023) Diversity and distribution of Orchidaceae in one of the world`s most threatened plant hotspots (Madagascar). Biodiversity Data Journal 11: e106223. https://doi.org/10.3897/BDJ.11.e106223

Global dataset of orchid specimens collected to date in Madagasca

Supplementary material 1 from: Droissart V, Verlynde S, Ramandimbisoa B, Andriamahefarivo L, Stévart T (2023) Diversity and distribution of Orchidaceae in one of the world`s most threatened plant hotspots (Madagascar). Biodiversity Data Journal 11: e106223. https://doi.org/10.3897/BDJ.11.e106223

Checklist of Orchidaceae collected in Madagascar between 1816 and 202

Diversity and distribution of Orchidaceae in one of the world’s most threatened plant hotspots (Madagascar)

Introduction. In recent decades, Madagascar has become one of the most important plant hotspots in the world. The country’s remaining forests and vegetation are disappearing at an alarming rate, while dozens of new species are discovered each year. Amongst the plant families that have long been studied, Orchidaceae appear as one of the most charismatic, diverse and of high conservation concern. Based on a reviewed, comprehensive herbarium dataset, we have compiled a curated checklist of all orchid species occurring in Madagascar. Based on this complete dataset, we then compiled sampling effort, species diversity distribution and some general statistics on their ecology and IUCN conservation status. Methods. We compiled and standardised a global dataset using five public databases as the main data sources, supplemented by the most recent publications. The database contains ~ 10,000 geolocated records collected between 1816 and 2021. We used GIS software and rarefaction methods to examine sampling and diversity patterns. Results. According to our dataset, there are currently 913 orchid species collected in Madagascar, of which 759 orchid species (83.1%) are endemic. Doubling the sampling effort could lead to the discovery of around 100 more species, bringing the total estimated number of orchid species in Madagascar to between 986 and 1048. About one-third (297 species) of all orchid species are known only by type specimens (189 species) or have not been collected in Madagascar for more than 50 years (214 species). Although the raw data show that the Andasibe-Moramanga area would have the highest orchid species concentration, our analysis of the data, adjusted for bias, shows that the centres of orchid diversity in Madagascar are in the Tsaratanàna Strict Nature Reserve and the Ranomafana National Park. Life-form statistics show that 55.0% of orchid species are strict epiphytes. The main flowering period of orchids in Madagascar is between November and March. To date, 84% of the 226 Malagasy orchid species listed in the IUCN Red List are threatened with extinction (CR, EN or VU). Conclusion. Despite geographically uneven coverage, the biodiversity of Malagasy orchids appears to be already well documented. We provide maps corrected for sampling bias that indicate priority areas for future surveys. Upcoming efforts should also focus on rediscovery and conservation of rare and/or threatened species and ensure that the protected area network is well aligned with the distribution of priority species for conservation. Finally, the conservation status of 75% of the orchid species found in Madagascar is not yet known and the inclusion of these species must be a top priority in the coming years.SCOPUS: ar.jinfo:eu-repo/semantics/publishe

Diversity and distribution of Orchidaceae in one of the world's most threatened plant hotspots (Madagascar)

Introduction. In recent decades, Madagascar has become one of the most important plant hotspots in the world. The country's remaining forests and vegetation are disappearing at an alarming rate, while dozens of new species are discovered each year. Among the plant families that have long been studied, Orchidaceae appear as one of the most charismatic, diverse and of high conservation concern. Based on a reviewed, comprehensive herbarium dataset, we have compiled a curated checklist of all orchid species occurring in Madagascar. Based on this complete dataset, we then compiled sampling effort, species diversity distribution, and some general statistics on their ecology and IUCN conservation status.Methods. We compiled and standardised a global dataset using five public databases as the main data sources, supplemented by the most recent publications. The database contains ~10 000 geolocated records collected between 1816 and 2021. We used GIS software and rarefaction methods to examine sampling and diversity patterns.Results. According to your dataset, there are currently 917 orchid species collected in Madagascar, of which 766 orchid species (83.5%) are endemic. Doubling the sampling effort could lead to the discovery of around 100 more species, bringing the total estimated number of orchid species in Madagascar to between 986 and 1056. About one-third (297 species) of all orchid species are known only by type specimens (190 species) or have not been collected in Madagascar for more than 50 years (213 species). Although the raw data show that the Andasibe-Moramanga area would have the highest orchid species concentration, our analysis of the data adjusted for bias shows that the centres of orchid diversity in Madagascar are in the Tsaratanàna Strict Nature Reserve and the Ranomafana National Park. Life form statistics show that 55.0% of orchid species are strict epiphytes. The main flowering period of orchids in Madagascar is between November and March. To date, 84% of the 226 Malagasy orchid species listed in the IUCN Red List are threatened with extinction (CR, EN or VU).Conclusion. Despite geographically uneven coverage, the biodiversity of Malagasy orchids appears to be already well documented. We provide maps corrected for sampling bias that indicate priority areas for future surveys. Upcoming efforts should also focus on rediscovery and conservation of rare and/or threatened species, and ensure that the protected area network is well aligned with the distribution of priority species for conservation. Finally, the conservation status of 75% of the orchid species found in Madagascar is not yet known, and the inclusion of these species must be a top priority in the coming years

Diversity and distribution of Orchidaceae in one of the world's most threatened plant hotspots (Madagascar)

Introduction. In recent decades, Madagascar has become one of the most important plant hotspots in the world. The country's remaining forests and vegetation are disappearing at an alarming rate, while dozens of new species are discovered each year. Amongst the plant families that have long been studied, Orchidaceae appear as one of the most charismatic, diverse and of high conservation concern. Based on a reviewed, comprehensive herbarium dataset, we have compiled a curated checklist of all orchid species occurring in Madagascar. Based on this complete dataset, we then compiled sampling effort, species diversity distribution and some general statistics on their ecology and IUCN conservation status.Methods. We compiled and standardised a global dataset using five public databases as the main data sources, supplemented by the most recent publications. The database contains ~ 10,000 geolocated records collected between 1816 and 2021. We used GIS software and rarefaction methods to examine sampling and diversity patterns.Results. According to our dataset, there are currently 913 orchid species collected in Madagascar, of which 759 orchid species (83.1%) are endemic. Doubling the sampling effort could lead to the discovery of around 100 more species, bringing the total estimated number of orchid species in Madagascar to between 986 and 1048. About one-third (297 species) of all orchid species are known only by type specimens (189 species) or have not been collected in Madagascar for more than 50 years (214 species). Although the raw data show that the Andasibe-Moramanga area would have the highest orchid species concentration, our analysis of the data, adjusted for bias, shows that the centres of orchid diversity in Madagascar are in the Tsaratanàna Strict Nature Reserve and the Ranomafana National Park. Life-form statistics show that 55.0% of orchid species are strict epiphytes. The main flowering period of orchids in Madagascar is between November and March. To date, 84% of the 226 Malagasy orchid species listed in the IUCN Red List are threatened with extinction (CR, EN or VU).Conclusion. Despite geographically uneven coverage, the biodiversity of Malagasy orchids appears to be already well documented. We provide maps corrected for sampling bias that indicate priority areas for future surveys. Upcoming efforts should also focus on rediscovery and conservation of rare and/or threatened species and ensure that the protected area network is well aligned with the distribution of priority species for conservation. Finally, the conservation status of 75% of the orchid species found in Madagascar is not yet known and the inclusion of these species must be a top priority in the coming years

Revision of <i>Angraecum</i> sect. <i>Perrierangraecum</i> (Orchidaceae; Epidendroideae; Vandeae) for the Mascarenes, with a description of a new endemic species for Mauritius

While revising the genus Angraecum (Orchidaceae) for the Mascarenes, a new taxon endemic to Mauritius was identified and it is here described as Angraecum baiderae. More than 300 Angraecum specimens, including types, collected in the Mascarenes and Madagascar, and available at DBEV, G, K, KM, L, MARS, MAU, MO, P, REU, SEY, TEF, and TAN were studied to confirm the taxonomic status of this new taxon. Its conservation status was assessed as Endangered. Furthermore, this paper presents detailed descriptions, conservation status, and a key to all species of Angraecum sect. Perrierangraecum occurring in the Mascarenes

The impact of chromosome number changes on the diversification of angraecoids in tropical Africa (Epidendroideae: Vandeae: Angraecinae)

International audienceThe impact of the widespread occurrence of polyploidisation anddescending dysploidy on lineage diversification has never been explicitly tested, to our knowledge, in Orchidaceae. Angraecoids (Vandeae: Angraecinae) present a diverse rangeof chromosome numbers which makes them a good study system to understand karyotype evolution and its role in cladogenesis. Within Angraecinae, two major clades are recognised: one mostly confined to Madagascar, where only x= 19 is reported; and the Afroneotropical clade, which apparently presents a rare example of ascending dysploidy in the orchid family, with c. 90% of its species inferred to have x = 25. In this study, we aimed to trace the evolution of the chromosome number in the Afroneotropical cladeand to test, for the first time, the likely impact of chromosome changes on diversification in Orchidaceae. By using a near-comprehensive phylogenetic tree of angraecoids at the genus level, including 280 species, we mapped the chromosome counts of 116 species in 35 genera. Accordingly, we inferred the ancestral haploid number of most Afroneotropical angraecoid genera, starting from x = 19, and we identified a total of three first step ascending dysploid events in Conchograecum(x= 21), Dendrophylax(x = 22) and in the ‘Aerangidinae’ (x= 25); and a single first-step descending dysploidy occurrence in Calyptrochilum(x = 17). Within the Aerangidinae clade nine independent second step descending dysploid events were identified, which define new generic and suprageneric synapomorphies, namely in Ancistrorhynchusand Microcoelia(x= 24); and in the Cyrtorchis-Tridactyleclade (x= 23). Furthermore, two secondary and one tertiary dysploid events were identified in Aerangisand Summerhayesia, respectively. Finally, nine neopolyploid events were identified in eight genera. These findings have allowed us to test whether there was a significant contribution of chromosome number evolution to the radiation of angraecoids in tropical Afric