Three new records of cheilanthoid ferns for Vietnam

Three new records of cheilanthoid ferns for Vietnam, i.e., Aleuritopteris sichouensis, A. formosana, and Cheilanthes fragilis are reported. Illustrations and notes on geographical distribution, habitat and taxonomy are also provided.

Indian Cheilanthoid fern - A numerical taxonomic approach

Twenty one species belonging to five genera (viz. Aleuritopteris F?e, Cheilanthes Sw., Doryopteris J. Sm., Notholaena R. Brown, Pellaea Link.) of the Indian cheilanthoid ferns were studied to develop the new data set of micromorphological details viz. epidermal cells, stomatal morphotypes, venation pattern and spore ultrastructre. Cluster analysis was performed by using the two- state of multiple characters that separate the genus Aleuritopteris from Cheilanthes at the Eucladian distance of 5.1, though completely linked with other closely related genera, viz. Doryopteris, Notholaena and Pellaea. The taxonomic conundrum lies within these genera was resolved with numerical taxonomic study.Bangladesh J. Plant Taxon. 23(2): 133-142, 2016 (December)

A study of chromosome and gametophyte development in Pellaea connectens C. Chr.

Pellaea connectens C. Chr., a cheilanthoid fern species, is rare and endemic to West Sichuan, China, and has an ambiguous taxonomical status. Recent molecular phylogenetic work has supported that it is a member of the genus Argyrochosma. In this research, we studied chromosome number and gametophyte development of this species to further elucidate its phylogenetic placement. We found that Pellaea connectens is a sexual tetraploid species with 64 spores per sporangium and with a base chromosome number of x = 27, which is consistent with Argyrochosma and different from other cheilanthoid ferns. We also found that the spore germination pattern of Pellaea connectens is of the Vittaria type and subsequent gametophyte development process is of the Ceratopteris type. All of the above concur with the characteristics of Argyrochosma nivea. Most of the gametophytes of Pellaea connectens reach an adult stage with a cordate symmetric shape, with a few developed as irregularly lobed prothalli. We conclude that cytology and gametophyte development characters support the previous taxonomic treatment of removing Pellaea connectens from Pellaea to Argyrochosma.

Identifying the generic limits of the Cheilanthoid genus Doryopteris

Morphology-based delimitation of genera in the Cheilanthoid ferns has proved to be problematic and understanding of the phylogeny and relationships amongst Cheilanthoid ferns based on morphological characters has posed even further difficulties, owing perhaps in large part to adaptation by many taxa to xeric habitats, as well as convergent evolution. It is only now with the application of DNA sequence data that relationships of species and genera are becoming clear. Here, we present results of cpDNA sequence data from species that have been traditionally placed in the genus Doryopteris and, based on both these results, and morphological and distribution data, this study helps clarify the concept of the genus Doryopteris its position within the Cheilanthoid ferns and the status of Lytoneuron. As a result, three genera are redefined: Doryopteris, Lytoneuron and Ormopteris.

Silver Ferns of Bangladesh and the exclusion of reported Aleuritopteris grisea (Blanf.) Panigrahi (Pteridophyta, Pteridaceae)

The three species of Aleuritopteris ("Silver Ferns") present in Bangladesh are discussed, A. bicolor (Roxb.) Fraser-Jenk, A. anceps (Blanf.) Panigrahi and A. subdimorpha (C.B.Clarke & Baker) Fraser-Jenk., correcting some previous erroneous reports. Aleuritopteris grisea (Blanf.) Panigrahi has recently been reported from the Chittagong Hills, S.E. Bangladesh. But that species is well known to be a high Himalayan Sino-Himalayan species of the Tibetan subtype, confined to the main Himalayan ranges and occurring from c. 2900 - 4000 m altitude. The specimen misreported as it from Bangladesh belongs to the low-altitude species, A. anceps (Blanf.) Panigrahi, which occurs from c. 300-750 m altitude and is a S.E. Asian (Malesian) element in the flora of the Indian subcontinent. This species was first knowingly collected in Bangladesh in the same District in 2003 by the present author, but unfortunately Bangladesh was then inadvertently omitted from its range in his monographic summary of Indian subcontinental cheilanthoid ferns. DOI: http://dx.doi.org/10.3329/bjb.v42i2.18020 Bangladesh J. Bot. 42(2): 195-206, 2013 (December)