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Ctenitis arthrothrix (Hook.) Tardieu. —A. Portion of lamina. —B. Portion of rachis with pinna (pubescence not illustrated here). —C. Detail of portion of abaxial costa with ctenitoid hairs. —D. Portion of lower surface of pinna showing abundant ctenitoid hairs. A from lectotype, K-000351161; B–D drawn by C. Christensen and reproduced from Christensen (1932b: pl. 13, figs. 1, 2, 3, respectively).
Source publication
A taxonomic revision of Ctenitis (C. Chr.) C. Chr. (Dryopteridaceae) from Africa and the Western Indian Ocean was carried
out. Forty species are recognized, of which 12 are described as new, eight are transferred to Ctenitis from other genera, and one
is elevated from variety to species and transferred from Aspidium Sw. to Ctenitis. These 21 nomenc...
Citations
... Its distribution encompasses the Neotropics (ca. 50 species; Viveros and Salino 2015), the African and Indian Ocean regions (40 species according to Duan et al. 2017), and the Asiatic-Pacific region, with the exclusion of the southernmost areas (Australia, New Zealand, New Caledonia;Ching 1938Ching , 1965. Diversity estimates for this last region remain uncertain in the absence of a recent taxonomic treatment, apart from a study in China where 10 species were recognized (Dong and Christenhusz 2013). ...
The Hawaiian Islands are an emblematic field to study evolution, with their very high rates of endemism and spectacular cases of insular speciation. Nevertheless, many Hawaiian lineages still deserve investigation, such as in the fern lineage. In this study, we address the question of the origin of the fern genus Ctenitis, which is present in the archipelago with two endemic species, Ctenitis squamigera and C. latifrons. Using a taxonomic sampling covering the pan-tropical distribution of the genus and three chloroplast DNA regions, we provide evidence that the genus in the Hawaiian Islands originated from a single long-distance dispersal from the Neotropics. This area is less represented than Asia and the South Pacific in the origin of Hawaiian ferns, but a Neotropical origin may be explained by the transportation of spores by tropical storms originating near Central America. Furthermore, the colonization of the Hawaiian Islands is estimated to have occurred between 4 [9-2] and 3 [7-1] mya. This timing is consistent with the ages of all main and extant islands of the archipelago, which already provided habitats for the establishment of the initial Ctenitis colonizer. In turn, this relatively late arrival to the islands and the related potentially low availability of ecological niches may have hampered diversification of the genus beyond the two extant species. ARTICLE HISTORY
... Its distribution encompasses the Neotropics (ca. 50 species; Viveros and Salino 2015), the African and Indian Ocean regions (40 species according to Duan et al. 2017), and the Asiatic-Pacific region, with the exclusion of the southernmost areas (Australia, New Zealand, New Caledonia;Ching 1938Ching , 1965. Diversity estimates for this last region remain uncertain in the absence of a recent taxonomic treatment, apart from a study in China where 10 species were recognized (Dong and Christenhusz 2013). ...
The Hawaiian Islands are an emblematic field to study evolution, with their very high rates of endemism and spectacular cases of insular speciation. Nevertheless, many Hawaiian lineages still deserve investigation, such as in the fern lineage. In this study, we address the question of the origin of the fern genus Ctenitis, which is present in the archipelago with two endemic species, Ctenitis squamigera and C. latifrons. Using a taxonomic sampling covering the pantropical distribution of the genus and three chloroplast DNA regions, we provide evidence that the genus in the Hawaiian Islands originated from a single long-distance dispersal from the Neotropics. This area is less represented than Asia and the South Pacific in the origin of Hawaiian ferns, but a Neotropical origin may be explained by the transportation of spores by tropical storms originating near Central America. Furthermore, the colonization of the Hawaiian Islands is estimated to have occurred between 4 [9-2] and 3 [7-1] mya. This timing is consistent with the ages of all main and extant islands of the archipelago, which already provided habitats for the establishment of the initial Ctenitis colonizer. In turn, this relatively late arrival to the islands and the related potentially low availability of ecological niches may have hampered diversification of the genus beyond the two extant species.
... A few were not corroborated in previous studies (Lehtonen et al., 2010;Link-Pérez, Watson & Hickey, 2011;Labiak et al., 2014;PPG I, 2016;Huiet et al., 2018), whereas many were found to be the result of LDD (e.g. Prado et al., 2013;Almeida et al., 2016;Gasper et al., 2016;Bauret et al., 2017aBauret et al., , b, 2018Duan et al., 2017). ...
... LDD is a key subject in biogeographical studies of ferns and lycophytes (Tryon, 1986;Barrington, 1993), and it appears to have a major impact in the current distribution of species-level lineages, as has been evidenced from this and other recent phylogenetic hypotheses, whereas vicariance probably had a major role in building biogeographical patterns over deep evolutionary scales for these plants (e.g. Lehtonen et al., 2010;Chao et al., 2014;Sundue et al., 2014;Labiak et al., 2015;Almeida et al., 2016;Hennequin et al., 2017;Vicent, Gabriel y Galán & Sessa, 2017;Bauret et al., 2018). Divergence times of most extant fern species from South America and African floras are younger than the Gondwana split and the separation of Africa and South America, so that at the specific level, the current disjunctions should reflect LDD rather than vicariance (e.g. ...
The epiphytic fern genus Microgramma (Polypodiaceae) comprises 30 species occurring mainly in the Neotropics, but with one species in Africa, an example of trans-Atlantic disjunction. Morphologically and ecologically, Microgramma presents a wide range of variation that is not seen in the most closely related genera. Recent studies have changed the circumscription of Microgramma to better conform with phylogenetic evidence, but no comprehensively sampled study has addressed the evolution of this lineage. The present study aimed to investigate phylogenetic relationships, ecology and morphological evolution and to test the role of long-distance dispersal in Microgramma. Sequences from five plastid regions were used to infer the phylogenetic relationships and estimate divergence times. Our results show five clades in Microgramma that do not corroborate any previously proposed infrageneric classification system. Several morphological traits appear to be homoplastic, including leaf dimorphism. Tuber-like myrmecodomatia are suggested to be synapomorphic for one clade, although ant-plant associations appear in two lineages. Microgramma lycopodioides in the Neotropics and M. mauritiana in Africa, once thought to be conspecific, are not closely related, with the African species nested in an Atlantic Forest clade, indicating a long-distance dispersal event estimated to have occurred c. 15 Mya from South America to Africa, followed by speciation.
... A few were not corroborated in previous studies (Lehtonen et al., 2010;Link-Pérez, Watson & Hickey, 2011;Labiak et al., 2014;PPG I, 2016;Huiet et al., 2018), whereas many were found to be the result of LDD (e.g. Prado et al., 2013;Almeida et al., 2016;Gasper et al., 2016;Bauret et al., 2017aBauret et al., , b, 2018Duan et al., 2017). ...
... LDD is a key subject in biogeographical studies of ferns and lycophytes (Tryon, 1986;Barrington, 1993), and it appears to have a major impact in the current distribution of species-level lineages, as has been evidenced from this and other recent phylogenetic hypotheses, whereas vicariance probably had a major role in building biogeographical patterns over deep evolutionary scales for these plants (e.g. Lehtonen et al., 2010;Chao et al., 2014;Sundue et al., 2014;Labiak et al., 2015;Almeida et al., 2016;Hennequin et al., 2017;Vicent, Gabriel y Galán & Sessa, 2017;Bauret et al., 2018). Divergence times of most extant fern species from South America and African floras are younger than the Gondwana split and the separation of Africa and South America, so that at the specific level, the current disjunctions should reflect LDD rather than vicariance (e.g. ...
The epiphytic fern genus Microgramma (Polypodiaceae) comprises 30 species occurring mainly in the Neotropics, but with one species in Africa, an example of transAtlantic disjunction. Morphologically and ecologically, Microgramma presents a wide range of variation that is not seen in the most closely related genera. Recent studies have changed the circumscription of Microgramma to better conform with phylogenetic evidence, but no comprehensively sampled study has addressed the evolution of this lineage. The present study aimed to investigate phylogenetic relationships, ecology and morphological evolution and to test the role of long-distance dispersal in Microgramma. Sequences from five plastid regions were used to infer the phylogenetic relationships and estimate divergence times. Our results show five clades in Microgramma that do not corroborate any previously proposed infrageneric classification system. Several morphological traits appear to be homoplastic, including leaf dimorphism. Tuber-like myrmecodomatia are suggested to be synapomorphic for one clade, although ant-plant associations appear in two lineages. Microgramma lycopodioides in the Neotropics and M. mauritiana in Africa, once thought to be conspecific, are not closely related, with the African species nested in an Atlantic Forest clade, indicating a long-distance dispersal event estimated to have occurred c. 15 Mya from South America to Africa, followed by speciation. ADDITIONAL KEYWORDS: ant-fern association-biogeography-ferns-frond dimorphism-homoplasy-long-distance dispersal.
... These 10 high-elevation species of Polystichum demonstrate that the karst terrains at high elevations in subtropical areas are species-rich and deserve special conservation attention. Right now much attention has been paid to tropical forests (e.g., Aedo 2016, 2017, Alejandro et al. 2016, Lucas et al. 2016, Mello-Silva & Sasaki 2016, O'Leary & Thode 2016, Duan et al. 2017, Morales et al. 2017, Szlachetko & Kolanowska 2018 Diagnosis:-Polystichum deltatum is most similar to P. crassirachis in having toothed upper pinna margins, but the former often has pinnae deltoid and pinna apex acute, while the latter has pinnae deltoid to oblong and pinna apex rounded. Plants perennial, evergreen, (19-)30-43 cm tall. ...
Eight new fern species of Polystichum subg. Haplopolystichum sect. Haplopolystichum (Dryopteridaceae) are described and illustrated from Guizhou Province, southwestern China. These eight species include P. anshunense, P. asperrimum, P. confusum, P. kropfii, P. libingii, P. macrodon, P. perditum, and P. yifanii. Each of these eight species was discovered from only 1–2 limestone caves showing extremely narrow distributions. Therefore, all are classified as Critically Endangered (CR) following IUCN Red List criteria.
... C.Chr., Dryopteridaceae;hennequin et al. 2017). Such a biogeographical approach requires accurate and updated taxonomy for local species (e.g., Duan et al. 2017 for Ctenitis). With at least 23 or 20 species, the hymenophyllaceae or filmy ferns represent one of the most diverse fern famillies in the Mascarenes, after Dryopteridaceae (43 species), Pteridaceae (40 species), and with almost the same number of species as Polypodiaceae and aspleniaceae (23 species for each family) (Tardieu-Blot 2008;Grangaud 2010;hennequin et al. 2014). ...
We here explore the diversity and ecology, and update the taxonomy of the fern family hymenophyllaceae, which forms one of the most diverse and emblematic fern assemblages in rainforests of the Mascarene archipelago in western Indian Ocean. Since 1999, we extracted data from floras, literature, and field investigations conducted, and from an exhaustive examination of the collections at P, ReU, and MaU. Our checklist recognizes 26 taxa involving 23 species, 2 local varieties and 1 new forma. We reconsider area of distribution in Mascarene hymenophyllaceae and at least 3 species appear to be restricted to the archipelago. We discuss the updated taxonomy and discrimination of each taxon (including a new nomenclatural proposition for Hymenophyllum tenellum here renamed as H. fumarioides) and provide a dichotomous key. We present and discuss the ecology and elevational distribution of each species, in addition to the local endemicity. Finally, we emphasize the importance of threatened lowland rainforests and of wet ravines in semi-dry forests, which host a high level of diversity in the context of local conservation of habitats.
... C.Chr., Dryopteridaceae;hennequin et al. 2017). Such a biogeographical approach requires accurate and updated taxonomy for local species (e.g., Duan et al. 2017 for Ctenitis). With at least 23 or 20 species, the hymenophyllaceae or filmy ferns represent one of the most diverse fern famillies in the Mascarenes, after Dryopteridaceae (43 species), Pteridaceae (40 species), and with almost the same number of species as Polypodiaceae and aspleniaceae (23 species for each family) (Tardieu-Blot 2008;Grangaud 2010;hennequin et al. 2014). ...
We here explore the diversity and ecology, and update the taxonomy of the fern family hymenophyllaceae, which forms one of the most diverse and emblematic fern assemblages in rainforests of the Mascarene archipelago in western Indian Ocean. Since 1999, we extracted data from floras, literature, and field investigations conducted, and from an exhaustive examination of the collections at P, ReU, and MaU. Our checklist recognizes 26 taxa involving 23 species, 2 local varieties and 1 new forma. We reconsider area of distribution in Mascarene hymenophyllaceae and at least 3 species appear to be restricted to the archipelago. We discuss the updated taxonomy and discrimination of each taxon (including a new nomenclatural proposition for Hymenophyllum tenellum here renamed as H. fumarioides) and provide a dichotomous key. We present and discuss the ecology and elevational distribution of each species, in addition to the local endemicity. Finally, we emphasize the importance of threatened lowland rainforests and of wet ravines in semi-dry forests, which host a high level of diversity in the context of local conservation of habitats.
... C.Chr., Dryopteridaceae;hennequin et al. 2017). Such a biogeographical approach requires accurate and updated taxonomy for local species (e.g., Duan et al. 2017 for Ctenitis). With at least 23 or 20 species, the hymenophyllaceae or filmy ferns represent one of the most diverse fern famillies in the Mascarenes, after Dryopteridaceae (43 species), Pteridaceae (40 species), and with almost the same number of species as Polypodiaceae and aspleniaceae (23 species for each family) (Tardieu-Blot 2008;Grangaud 2010;hennequin et al. 2014). ...
We here explore the diversity and ecology, and update the taxonomy of the fern family hymenophyllaceae, which forms one of the most diverse and emblematic fern assemblages in rainforests of the Mascarene archipelago in western Indian Ocean. Since 1999, we extracted data from floras, literature, and field investigations conducted, and from an exhaustive examination of the collections at P, ReU, and MaU. Our checklist recognizes 26 taxa involving 23 species, 2 local varieties and 1 new forma. We reconsider area of distribution in Mascarene hymenophyllaceae and at least 3 species appear to be restricted to the archipelago. We discuss the updated taxonomy and discrimination of each taxon (including a new nomenclatural proposition for Hymenophyllum tenellum here renamed as H. fumarioides) and provide a dichotomous key. We present and discuss the ecology and elevational distribution of each species, in addition to the local endemicity. Finally, we emphasize the importance of threatened lowland rainforests and of wet ravines in semi-dry forests, which host a high level of diversity in the context of local conservation of habitats.
... These 10 high-elevation species of Polystichum demonstrate that the karst terrains at high elevations in subtropical areas are species-rich and deserve special conservation attention. Right now much attention has been paid to tropical forests (e.g., Aedo 2016, 2017, Alejandro et al. 2016, Lucas et al. 2016, Mello-Silva & Sasaki 2016, O'Leary & Thode 2016, Duan et al. 2017, Morales et al. 2017, Szlachetko & Kolanowska 2018 Diagnosis:-Polystichum deltatum is most similar to P. crassirachis in having toothed upper pinna margins, but the former often has pinnae deltoid and pinna apex acute, while the latter has pinnae deltoid to oblong and pinna apex rounded. Plants perennial, evergreen, (19-)30-43 cm tall. ...
Eight new fern species of Polystichum subg. Haplopolystichum (Dryopteridaceae) are described and illustrated from Guangdong and Yunnan provinces, southern and southwestern China, respectively. These eight species include P. deltatum, P. gejiuense, P. malipoense, P. oblongipinnarum, P. pingbianense, P. rectum, and P. superum from Yunnan, and P. hanmengqii from Guangdong. Four of the eight species are described from high elevations (around 2000 m) demonstrating that the limestone areas at high elevations in subtropical areas are species-rich and deserve special conservation attention. All eight species are so far known only from single caves; they are all classified as Critically Endangered (CR) following IUCN Red List criteria.
... Chr.) C. Chr. (e.g., Duan et al., 2017), Polystichum Roth (e.g., Han et al., 2016). This hypothesis is partially supported by the fact that there are limited number of morphological characters available for taxonomy in Hymenasplenium (Wu, 1999;Lin and Viane, 2013). ...
... Interestingly, higher species diversity in Hymenasplenium is found in subtropical areas other than in tropical areas, contrasting general patterns that tropical forest supports higher plant diversity in general (e.g., Aedo, 2016, 2017, Alejandro et al., 2016, Faria and Araujo, 2016, Lucas et al., 2016, Mello-Silva and Sasaki, 2016, O'Leary and Thode, 2016, Duan et al., 2017, Morales et al., 2017. ...
The fern genus Hymenasplenium (Aspleniaceae) is one of the two genera in the family. It is generally recognized among modern pteridologists. However, its infrageneric relationships and species diversity have been unclear and controversial. The molecular studies so far have had small taxon and character sampling. In the present study, DNA sequences of six plastid markers of 158 accessions representing ca. 40 out of ca. 50 known species of Hymenasplenium, and 16 species of Asplenium were used to infer a phylogeny with maximum likelihood, Bayesian inference, and maximum parsimony approaches. Our major results include: (1) Hymenasplenium as currently defined is strongly supported as monophyletic; (2) three major clades representing early splits in Hymenasplenium are identified, with the Old World species being strongly supported as monophyletic; it is ambiguous if the New World species are monophyletic; (3) extensive cryptic speciation in the Old World is discovered demonstrating the complexity of evolution of the genus; and (4) six strongly or moderately supported subclades in the Old World clade are revealed, differing from one another in molecular, morphological, and geographical features.
