Three new fossil records of Equisetum (Equisetaceae) from the Neogene of south-western China and northern Vietnam Author Aung, Aye Thida Author Huang, Jian Author Do, Truong Van Author Song, Ai Author Liu, Jia Author Zhou, Zhe-Kun Author Su, Tao text PhytoKeys 2020 138 3 15 http://dx.doi.org/10.3897/phytokeys.138.38674 journal article http://dx.doi.org/10.3897/phytokeys.138.38674 1314-2003-138-3 70E33E044DB551A7A3994CC1BB33ABA6 Equisetum yongpingense A.T.Aung, T.Su & Z.K. Zhou sp. nov. Holotype. XTBGYP0748 (Fig. 3A ). Paratypes. XTBGYP0747 (Fig. 3B ), XTBGYP1014 (Fig. 3C ), XTBGYP1015 (Fig. 3D ), XTBGYP0750 (Fig. 3E ), XTBGYP0749 (Fig. 3F ). Figure 3. Equisetum yongpingense A.T.Aung, T.Su & Z.K.Zhou, sp. nov. Specimen numbers: A XTBGYP0748 B XTBGYP0747 C XTBGYP1014 D XTBGYP1015 E XTBGYP0750 F XTBGYP0749. Scale bars: 1cm. Locality. Sanying Formation, Longmen Village, Yongping County, western Yunnan Province, south-western China ( 25.518N , 99.519E ). Age. The late Pliocene. Repository. Paleoecology Collections, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences. Etymology. The species name ' yongpingense ' means that fossils are from Yongping County, south-western China. Diagnosis. Rhizomes with internodes and round nodes; fibrous roots on most nodes; two to four bunches of tubers arranged in a whorl on a node (Fig. 3A ); tubers cylindrical in shape, one to two tubers on each bunch (Fig. 3A-B ); longitudinal ridges not observed on the surface of tuber; the tip of tuber mucronate (Fig. 3A ). Description. Rhizomes have both internodes and nodes (Fig. 3A ). The internode is ~0.5 to 0.8 cm wide, the length is up to 5.1 cm (Fig. 3A ). The node is round and ~0.7 to 1.0 cm in diameter (Fig. 3A-B ). Most nodes have fibrous roots ~ 0.1 to 0.2 cm wide. Two to six bunches of tubers attach on one node and are arranged in a whorl (Fig. 3A-B ). One to two tubers are preserved on each bunch (Fig. 3A-B ). Tubers are cylindrical, ~ 1.5 to 3.4 cm long and 0.6 to 1.2 cm wide (Fig. 3A-F ). Ridges were not observed on the surface of each tuber (Fig. 3A-B, E ). The tip of tuber is mucronate (Fig. 3A ).