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| Ophioglossum trilokinathii B. L. Yadav, M. K. Meghvansi, K. Meena & C. B. Gena, in Yadav, Meghvansi, Meena & Gena, 2021. |
Abstract
Eusporangiate fern genus Ophioglossum L. is commonly known as Adder’s tongue fern as its fertile frond gives the appearance of snake tongue. A new species in this fern genus, O. trilokinathii belonging to Ophioglossaceae family has been discovered from the plateau region of Rajasthan State of northwestern India. The new species can be distinguished from other taxa of this genus by its smaller habit, subglobose-tuberous rhizome, basipetal emergence of young roots, aggregation of old decaying roots on rhizome apex, fertile stalk as well as spike short and thick, trophophylls in rosette, ovate or orbicular and a unique sporoderm sculpture pattern under SEM having broad reticulations with thick and raised muri enclosing large hexagonal or irregular areas on the distal and proximal faces of the spores hitherto unreported in any of the presently known taxa of Ophioglossum. In addition, comparative study of stomatal structure, foliar anatomy and nucleotide sequence data of its three chloroplast DNA markers (trnL-F, rbcL and psbA-trnH) was carried out. In view of all the attributes including habitat, ecology, morphology, foliar anatomy, stomatal features, palynology and molecular phylogenetic data, the present study suggests that the Ophioglossum specimen collected from plateau region of Rajasthan represents a hitherto undescribed species thereby warranting its establishment as O. trilokinathii sp. nov. A detailed comparative account of the new taxon with its allied species has also been provided.
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| Ophioglossum trilokinathii sp. nov. (A) Habitat. (B) Entire plant with aggregation of roots of previous season (older roots) at rhizome apex. (C) Rhizome showing basipetal emergence of roots. (D) Trophophyll-size, shape and venation. |
Ophioglossum trilokinathii B. L. Yadav, M. K. Meghvansi, K. Meena & C. B. Gena sp. nov.
Diagnosis: Ophioglossum trilokinathii sp. nov. is unique among the species of this genus in having basipetal emergence of roots, aggregation of old decaying roots at rhizome apex, trophophylls in rosette touching the substratum, peculiar broad reticulate spore wall ornamentation with thick and raised muri enclosing large hexagonal or irregular areas, granulose perine (perispore), differentiation of mesophyll cells into palisade and spongy tissues and elliptic stomata with thin and smooth inner margin of outer stomatal ledge.
Etymology: The specific epithet has been chosen in honour of Professor Triloki Nath Bhardwaja (Professor T. N. Bhardwaja), Former Vice-Chancellor, V. M. Open University, Kota, Rajasthan, India for his commendable work in the field of pteridology.
B. L. Yadav, Mukesh K. Meghvansi, Kanta Meena and C. B. Gena. 2021. Discovery of A New Species of Adder’s Tongue Fern from India with Comparative Analysis of Morphological and Molecular Attributes. Scientific Reports. 11; 24396. DOI :10.1038/s41598-021-03231-w
