Browsing by Author "Prado, J"

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    A worldwide phylogeny of Adiantum (Pteridaceae) reveals remarkable convergent evolution in leaf blade architecture
    (Taxon, 2018-06-01) Huiet, L; Li, F; Kao, T; Prado, J; Smith, AR; Schuettpelz, E; Pryeri, KM
    © International Association for Plant Taxonomy (IAPT) 2018, All rights reserved. Adiantum is among the most distinctive and easily recognized leptosporangiate fern genera. Despite encompassing an astonishing range of leaf complexity, all species of Adiantum share a unique character state not observed in other ferns: sporangia borne directly on the reflexed leaf margin or “false indusium” (pseudoindusium). The over 200 species of Adiantum span six continents and are nearly all terrestrial. Here, we present one of the most comprehensive phylogenies for any large (200+ spp.) monophyletic, subcosmopolitan genus of ferns to date. We build upon previous datasets, providing new data from four plastid markers (rbcL, atpA, rpoA, chlN) for 146 taxa. All sampled taxa can be unequivocally assigned to one of nine robustly supported clades. Although some of these unite to form larger, well-supported lineages, the backbone of our phylogeny has several short branches and generally weak support, making it difficult to accurately assess deep relationships. Our maximum likelihood-based ancestral character state reconstructions of leaf blade architecture reveal remarkable convergent evolution across multiple clades for nearly all leaf forms. A single unique synapomorphy—leaves once-pinnate, usually with prolonged rooting tips—defines the philippense clade. Although a rare occurrence in Adiantum, simple leaves occur in three distinct clades (davidii, philippense, peruvianum). Most taxa have leaves that are more than once-pinnate, and only a few of these (in the formosum and pedatum clades) exhibit the distinct pseudopedate form. Distributional ranges for each of the terminal taxa show that most species (75%) are restricted to only one of six major biogeographical regions. Forty-eight of our sampled species (nearly one-third) are endemic to South America.
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    Are there too many fern genera?
    (Taxon, 2018-06-01) Schuettpelz, E; Rouhan, G; Pryer, KM; Rothfels, CJ; Prado, J; Sundue, MA; Windham, MD; Moran, RC; Smith, AR
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    Phylogeny and relationships of the neotropical Adiantum raddianum group (Pteridaceae)
    (Taxon, 2016-12-01) Hirai, RY; Schuettpelz, E; Huiet, L; Pryer, KM; Smith, AR; Prado, J
    © International Association for Plant Taxonomy (IAPT) 2016. With more than 200 species, the maidenhair fern genus Adiantum is among the top ten most diverse fern genera. Adiantum is pantropical in distribution and, due to the presence of a unique synapomorphy (sporangia borne on indusia rather than laminae), perhaps the most easily recognized fern genus. Many of its members, including numerous cultivars derived from A. raddianum, are grown as ornamentals. Because of its size, a comprehensive taxonomic study of Adiantum is difficult and the genus is perhaps better approached through a series of narrower studies. Here, we focus specifically on A. raddianum and putative allies. We find a newly defined A. raddianum group to be strongly supported as monophyletic and segregated from other maidenhair ferns on the basis of genetic as well as morphological characteristics. Bayesian inference and maximum likelihood analyses of plastid atpA, chlL, chlN, rbcL, and rpoA sequences support the A raddianum clade as sister to A poiretii and its allies. We identify round-reniform indusia to be a characteristic of the A.raddianum group (vs. lunate in the A.poiretii group). Additionally, we find species in the Apoiretii group to differ in having a unique 66 nucleotide deletion in our chlN gene alignment. The neotropical Araddianum group comprises at least 17 species (14 studied here), some widely distributed; one was recently described (A. alan-smithii).