It was business as usual in Pune’s Agharkar Research Institute when in 2015, Dr G Ramachandra Rao, an Assistant Professor at MES College of Arts, Commerce and Science, Bengaluru, approached Dr Ritesh Kumar Choudhary, a scientist at the institute. He held out a few samples of a grass-like plant with tiny flowers that he had collected from the Uttara Kannada district in Karnataka. Dr Choudhary immediately recognised that it was a kind of pipewort, but which one? That was a billion-dollar question!
Pipeworts, or Eriocaulon, are called taxonomists’ nightmare for good reasons—plants of different species of this genus are very similar to each other and hence, hard to tell apart. “Even the famous taxonomist, Sir Joseph Dalton Hooker, has expressed that Eriocaulon is one of the most difficult groups to identify, in his book The Flora of British India—the first comprehensive account of India’s plants,” shares Dr. Choudhary. “Indian taxonomists like R Ansari and N P Balakrishnan, who have divided this genus into 12 taxonomic sections, had also raised their concerns on the classification of these plants,” he adds.
However, this time, the researchers seem to have cracked it. In a recently published study in the journal Annales Botanici Fennici, Dr Choudhary along with his Ph.D. student Ms. Ashwini Darshetkar, and research colleagues Dr Rao, Dr. Mandar, Dr. Tamhankar and Dr Prabhukumar have described the specimen as a new species of pipeworts after studying the different parts of the plant and its DNA. The researchers have named the new species Eriocaulon karaavalense, after the Kannada work karaavali (ಕರಾವಳಿ), which translates to ‘the coast’.
Around the world, there are 471 species of pipeworts, and about a fourth of them are found in India. The mountains of the Western Ghats hosts about 60 species and a few are found in the northeastern states, where the flowers are used in bouquets. These plants prefer acidic soil to grow and some species act as indicators of heavy metal contamination in the soil. A Chinese pipewort species E. buergerianum is known to be anti-inflammatory, antimicrobial and has the potential to prevent nerve damage. Another species, E. cinereum (=E. sieboldianum), commonly found in India is known for its anti-cancerous properties.
When the researchers studied the tiny flowers and seeds of E. karaavalense under a microscope, they observed ribbon-like bands or appendages on the surface of the seeds. Besides, a small, gland-like structure was found on its petals. These two features helped to distinguish this plant from another closely resembling species, E. kanarense. They also amplified a portion of the DNA of this plant and compared it with the DNA sequences from other known species to ensure its uniqueness.
If not observed carefully, identification based on the appearance of different plant parts can be misleading at times. "Minor variations occur within a species, and one might go wrong and mark them as a new species if not studied carefully", explains Ms. Ashwini, who is conducting DNA-based studies that could ultimately help to correct such wrongly identified ‘species’.
The new species, E. karaavalense, germinates after monsoons with leaves appearing in June and flowers in August. The seeds of the plant, dispersed after rains, wait for the next monsoon before they germinate. The leaves look like grass blades and the flowers, which are borne on head-like structure on long stalks, helps to distinguish them from the grass. This discovery adds to the body of work these researchers are doing in the past five years. In 2017, they had described another species, E. parvicephalum, from the Western Ghats.
Apart from studying on how different species of pipeworts are related to each other and how they evolved, the researchers are also trying to barcode the DNA of these plants to identify a species by looking at a short DNA sequence. “Identifying these plants is difficult today because of its small size, or when the flower is absent. With barcodes, one would be able to recognise a plant with just a leaf”, explains Dr Choudhary, sharing the ambition of having a barcode for each species in India.
The discovery of more pipeworts from India seems to be in the pipeline. "I think there are some unexplored species in the North East, like those in Meghalaya and Nagaland, which need proper exploration,” concludes Dr Choudhary.
This article was published with support from the India Science Media Fellowship 2019 by the Wellcome Trust/DBT India Alliance and Nature India.
This article has been run past the researchers, whose work is covered, to ensure accuracy.