The genus Ophioglossum belongs to the family of Adder’s Tongue Ferns (Ophioglossaceae), a cosmopolitan group. Their name derives from the shape of the spore-bearing structure of the family, which is shaped like a snake’s tongue. While there is nothing particularly remarkable about these plants, they do have some of the highest number of chromosomes in the living kingdom. For example, one species, Ophioglossum reticulatum has 1260 chromosomes.
Of late, news reports have appeared in the Indian media about the discovery of the world’s smallest land fern, one Ophioglossum malviae or Malvi’s Adder’s Tongue Fern in the Ahwa Forest of the Gujarat’s Dang District (Gujarat being a state along India’s western seaboard). The hills where the discovery was made are an extension of the Western Ghats, one of the world’s biodiversity hotspots. Given below is a report from The Hindu newspaper describing the discovery of this miniscule plant:
Indian researchers have discovered the world’s smallest land fern hiding in the Ahwa forests of the Western Ghats in Gujarat’s Dang district. According to a recent study in Scientific Reports, an international journal that publishes multidisciplinary research, the fingernail-sized fern belongs to a group known as the adder’s-tongue ferns, named after their resemblance to a snake’s tongue.
The size of the new Malvi’s adder’s-tongue fern Ophioglossum malviae – just one centimetre – is probably the reason why it remained hidden all along, said researcher Mitesh Patel of the Department of Biosciences at Surat’s Veer Narmad South Gujarat University, who stumbled across the plant during a botanical expedition in 2016. According to Mr. Patel, he was lying on his stomach and looking for other small Ophioglossum ferns in the Ahwa forest division when he came across the distinct fern.
Taking it back to the lab, Mr. Patel and his colleagues studied its morphology in detail to find that it differed from similar ferns in not just size (the most similar adder’s-tongue fern is 10 cm tall) but other complex fern features too. A look at the plant’s minuscule seeds (called spores) under a powerful electron microscope revealed it had a unique thick outer layer which similar species lacked. The researchers also analysed the plant’s DNA and found it to vary enough from its relatives to call it a new species.
Initial observations suggest that the ferns are seasonal and grow with the first monsoon rains, said Mr. Patel. “They last only for a few months and new plants are born through their spores next year,” he pointed out. The ferns are not very common even in the locality they are found in. In fact, the researchers uncovered only 12 of these plants in the Ahwa forest division, growing alongside mosses in grasslands near Jakhana village. Since locals use the grasslands as a burial ground, conserving the species is crucial, added Mr. Patel.
“It is fascinating that the fern has been found from one of the drier tracts of the Ghats,” said T. V. Ramachandra, Senior Scientist, Energy & Wetlands Research Group at CES of Bengaluru’s Indian Institute of Science, who was not involved in the study. “This also highlights the need for more field surveys across the Ghats, before many such unexplored patches are destroyed,” the scientist said.
Image Attribution: The image above, sourced from Wikimedia Commons, is the illustration of a related species – Ophioglossum vulgatum which happens to be cosmopolitan, found in North America, Europe, Africa and Asia. The illustration appeared in a book by Prof. Dr. Otto Wilhelm Thomé (Flora von Deutschland) in the year 1885, in Gera, Germany.
- Western Ghats Reveal World’s Smallest Land Fern (dated April 24, 2018 by Aathira Perinchery), The Hindu