The Lycophytes were one of the first groups of Vascular Plants to emerge in the Silurian, and remained one of the dominant Plant groups throughout the Palaeozoic. Lycophytes reproduce by means of spores, have vascular tissue, unlike True Mosses, Hornworts, and Liverworts (although this is arranged in a different way to all other Vascular Plants), but unlike other Vascular Plants lack true leaves, instead having microphylls, short flattened stems which form a scale-leaf with unbranching veins. The most notable fossil members of this group are the giant Lepidodendrales trees which dominated the coal forests of the Carboniferous. Today this group is represented by only a few species of Clubmosses, Spikemosses, and similar forms. The genus Selaginella has a fossil record dating back to the Late Carboniferous, and is the sole surviving genus of Spikemoss, with representatives found in tropical forests around the world.
In a paper published in the journal PhytoKeys on 7 June 2023, Shao-Li Fang of the School of Ecology and Environmental Science & School of life Sciences at Yunnan University, Bo Xu of the Key Laboratory of Mountain Ecological Restoration and Bioresource Utilization and the Ecological Restoration and Biodiversity Conservation Key Laboratory of Sichuan Province at the Chengdu Institute of Biology, Liang Zhang of the Key Laboratory for Plant Diversity and Biogeography of East Asia at the Kunming Institute of Botany, and Zhao-Rong He and Xin-Mao Zhou, also of the School of Ecology and Environmental Science & School of life Sciences at Yunnan University, describe a new species of Selaginella from Medog County in southern Tibet.
Medog County is located in the southeast of Tibet, forming part of the Eastern Himalaya Biodiversity Hotspot, along with Bhutan, most of Nepal, and parts of north and northeast India. The county is considered to be one of the most biodiverse in China, with more species discovered there in 2020 than any other county in the country.
During fieldwork in June 2015 and October 2017, specimens of a Spikemoss which did not conform to any known species were collected from a broad-leaved evergreen forest, at an elevation of 1600 m, close to the township of Beibeng. These were later confirmed to be a new species by DNA analysis. The new species is named Selaginella densiciliata, where 'densiciliata' means densely ciliated, in reference to the sterile (non-spore bearing) microphylls of the Plant, which have a dense covering of cilia.
Selaginella densiciliata is a terrestrial evergreen herbaceous Plant reaching 7-15 cm in height. The main stem is unbranching for 0.5-3.5 cm, then produces 6-13 pairs of pinately dividing branches. Four rows of sterile microphylls are present from the base to the middle of the stem.
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