Physcomitrium eurystomum Sendtn. (Funariaceae): a rare species recorded for Assam, India

In this study, distributional record of the moss Physcomitrium eurystomum Sendtn. for the state of Assam is established for the first time. Taxonomic description and illustration of the same, based on specimens collected from Kamrup and Morigaon districts of the state are provided.

The moss genus Physcomitrium (Brid.)Brid.(Funariales: Funariaceae) has 80 species spread across wet and cool areas of the world (Bansal & Srivastava 2017) and 13 species belonging to this genus were reported from India (Dandotiya et al. 2011).Eastern India and the Gangetic Plains have been reported to be home to seven different species of this genus (Gangulee 1974).Six species within the genus were found in Eastern Himalaya and Punjab (Gangulee 1974;Lal 2005), followed by the Gangetic Plains and western Himalaya with five species each (Gangulee 1974;Alam 2013;Schwarz 2016), four species from the Western Ghats (Daniels 2010;Schwarz 2016;Bansal & Srivastava 2017).Five species of the genus-Physcomitrium acuminatum, P. brevinervis, P. japonicum, P. pulchellum, and P. repandum-were reported from the state of Assam (Dandotiya et al. 2011).
Physcomitrium eurystomum Sendtn.was reported from eastern Himalaya by Lal (2005), but the precise location of its occurrences was not specified.Manju et al. (2023) reported this rare species from the Western Ghats of Kerala stated "It is also known to occur in Lower Bengal and Assam in northeastern India and Parasnath Wildlife Sanctuary in Jharkhand in central India (Saha & Singh 2020)".However, Saha & Singh (2020) never reported the species from Assam.In India, the species is known from Hoogli & Burdwan in West Bengal, Kumaon in Uttarakhand (Gangulee 1974), Jharkhand (Saha & Singh 2020), Kerala (Manju et al. 2023), Banswara (Rana 2020), and Manipur (Dandotiya et al. 2011;Govindapyari et al. 2012;Asthana et al. 2021).Though Schwarz (2016)  In the present communication, detailed illustrated description of the species is provided with notes on its habitat and distribution within and outside.

Materials and Methods
Extensive bryofloristic exploration in the Kamrup district since 2020 till 2023 was conducted.The sporophyte-bearing plants of Physcomitrium eurystomum were collected from the study area, where these species grew abundantly from November to February.The specimens were collected and field observations were recorded based on the methodology provided by Glime (2017) and digital photographs of the habit and habitat were taken using a digital camera (Nikon, D-5600).The parts of the plant were dissected using a Stereo Zoom dissecting microscope, and further study was carried out using compound light microscope, and their size were measured using an Ocular micrometer (ERMA) by calibrating with a known scale provided by a Stage micrometer (ERMA) to ensure the accuracy of the measurement.Taxonomic literature (Rana 2020;Saha & Singh 2020;Manju et al. 2023) were consulted to determine the identity of the species.Voucher specimens were prepared following Glime & Wagner (2017).One set of the specimens are kept in the Herbarium of the Department of Botany, University of Delhi (DUH) and the duplicates in the Herbarium of the Department of Botany, Cotton University.
Habitat: The species was observed in shady, moist, muddy soil in association with grasses, and herbs.
listed this species from Assam, but without any specific locality and literature or specimen reference.The present collection of Physcomitrium eurystomum from the Cotton University campus and the vicinity of Chandubi lake of Kamrup and Ahatguri of Morigaon district of Assam, therefore, for the first time authentically establishes its record from the state.SHORT COMMUNICATION Abstract: In this study, distributional record of the moss Physcomitrium eurystomum Sendtn.for the state of Assam is established for the first time.Taxonomic description and illustration of the same, based on specimens collected from Kamrup and Morigaon districts of the state are provided.