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Summary: The genus Aerangis Schltr. (Orchidaceae, subfamily Epidendroideae, tribe Vandeae, subtribe Angraecinae) in Madagascar and adjacent archipelagos is revised. Twenty-seven species have been recorded from the region, all of them endemic. Twenty of these are endemic to Madagascar, three to the Comoros only, three to the Comoros and Madagascar and one to Madagascar and Réunion. A third of all Aerangis in the area were assessed to be immediately endangered with 15% Critically Endangered (CR) and 18.5% Endangered (EN). 37% are considered Vulnerable (VU), 15% Near Threatened (NT) and 11% are of Least Concern (LC). Section Microterangis (Schltr.) Hermans is newly established. All the species are described and their typification, history, identification, pollination, distribution and habitat are discussed. The nomenclature and identity of Aerangis citrata (Thouars) Schltr., A. cryptodon (Rchb.f.) Schltr., A. ellisii (B.S.Williams) Schltr., A. hildebrandtii (Rchb.f.) P.J.Cribb & Carlsward, A. ikopana Schltr., A. modesta (Hook.f.) Schltr., A. monantha Schltr., A. polyura (Sander ex Mast.) Hermans and A. rostellaris (Rchb.f.) H.Perrier, are reassessed. Conservation assessments, illustrations and distribution maps are included for all the species. A checklist of the sections, species and a key to their identification are provided. Aerangis bursiculata Hermans is described from the Comoros for the first time. [ABSTRACT FROM AUTHOR]

Summary: A new species from Madagascar, Bulbophyllum lanterna Hermans, is described and illustrated. It is compared with similar species from section Lichenophylax. A preliminary conservation assessment is provided. [ABSTRACT FROM AUTHOR]

Summary: A new species from Madagascar, Angraecum inflatum Hermans, is described and illustrated for the first time. It is compared with similar species from section Lemurangis. A preliminary conservation assessment is provided. [ABSTRACT FROM AUTHOR]

Summary: Five new species from Madagascar, Aerangis bovicornu (Vandeae: Angraecinae), Angraecopsis lemurelloides (Vandeae: Angraecinae), Didymoplexis stella-silvae (Gastrodieae), Habenaria crocodilium (Orchideae: Orchidinae) and Polystachya siederi (Vandeae: Polystachinae) are described and illustrated. A short summary of endemism and the history of description of orchids of Madagascar are given. [ABSTRACT FROM AUTHOR]

Summary: Six new species: Bulbophyllum caniceps, B. cochinealloides, B. fierenanaense, B. geminiflorum, B. oenanthum and B. rudolphus are described for the first time. The identity and nomenclature of Bulbophyllum cylindrocarpum is discussed and its var. andringitrense is recognised at species rank as B. jeanbosseri. Bulbophyllum aubrevillei and B. kieneri are compared with the latter becoming a synonym. The history and identities of Bulbophyllum pentastichum vs B. quadrifarium are clarified and the necessary taxonomic changes and type selections are made. A new sect. Inversiflora is formally described. [ABSTRACT FROM AUTHOR]

Summary: Three new species: Angraecum archangelicum, A. polyphemus and A. rotundifolium are described for the first time. Pectinariella is evaluated; a case is made to keep it at subgeneric level and the necessary two new combinations are made. Angraecum dasycarpum is neotypified. Finally A. ochraceum and A. setipes are compared with the latter being reduced to a synonym of the former. [ABSTRACT FROM AUTHOR]

Summary: Four new species, Cynorkis kiehnii, C. marianneae, C. marmorata and C. murex, are described for the first time. Cynorkis frappieri and C. raymondiana are compared, with the latter reduced to a synonym of the former. Cynorkis gaesiformis, C. galeata, C. nutans and C. stenoglossa are compared and considered one variable species, with the name C. nutans having priority. Additional information is provided about C. mammuthus following the discovery of living material in N Madagascar. [ABSTRACT FROM AUTHOR]

Background: Tropical orchids need more study with respect to their mycorrhizal associations. For researchers in distant countries who aspire to study these orchids augmenting their conservation, the great distances involved, coupled with limited funds, pose formidable challenges. These challenges are sometimes exacerbated by political unrest, delays in securing permits, unexpected hardships, and the risk that the biological samples collected (e.g., roots harboring mycorrhizal fungi) will not survive long-distance transport. Results: We describe a protocol for the collection and transport of root samples from Madagascar orchids to labs in the United Kingdom (Kew) and the United States (Illinois) where Rhizoctonia-like fungi were subsequently isolated. Three separate trips were made spanning 4 years (2012-2015), with emphasis on the collection of roots from epiphytic, lithophytic, and terrestrial orchids inhabiting the Itremo Massif of the Central Highlands. Collectively, the trips to Madagascar resulted in the isolation of all major groups of Rhizoctonia-like fungi ( Ceratobasidium, Tulasnella, Sebacina) from all three orchid growth forms (terrestrials, epiphytes and lithophytes). Sampling of terrestrial and epiphytes during the rainy season (January) yielded best results. Conclusions: Our study demonstrates that peloton-forming fungi in root samples can retain viability up to 3 weeks after collection. [ABSTRACT FROM AUTHOR]

Background: Lack of phenological information and efficient collecting methods are considered impediments for orchid seed collecting. This leads to opportunistic collecting as part of general seed collecting schedules that may last few weeks especially in remote areas. The study explored the feasibility of collecting near mature and immature seeds to support conservation action plans. Mature, near mature and immature seeds of orchids were collected from the wild in the Central Highlands of Madagascar (CHM). Seed capsules were collected in sterile culture medium in the wild, to prevent deterioration of seeds inside the capsule after collecting, later to be cultured under laboratory conditions. Results: Seed capsules collected by the in vitro collecting (IVC) method were kept in very good condition for up to 4 weeks before germination under in vitro conditions. Significantly faster and higher germination rate ( p < 0.001) than mature seeds was observed in a number of taxa collected during a 3 year-long study. In some taxa even immature seeds, with no apparent sign of testa covering the embryo, germinated following IVC where mature seeds failed to germinate. Conclusions: We propose that IVC method has potential to complement conventional seed collecting by increasing the germplasm that can be used in integrated conservation action plans. Improvements can be made in developing collections for taxa from biodiversity hotspots and remote areas where collecting requires considerable resources. This method can further be used on a wider selection of plants from different geographic areas and on embryo rescue programmes for economically important plants. [ABSTRACT FROM AUTHOR]