Revision of the genus Sirodotia Kylin (Batrachospermales, Rhodophyta) with description of four new species Author Rossignolo, Natalia L. São Paulo State University, Zoology and Botany Department, Cristóvão Colombo, 2265, 15054 - 000 São José Rio Preto, São Paulo (Brazil) Author Vis, Morgan L. Ohio University, Department of Environmental and Plant Biology, OH (United States) Author Paiano, Monica O. University of Hawaï, School of Life Sciences, Honolulu, HI (United States) Author Eloranta, Pertti Sinkilätie 13, Jyväskylä FI- 40530 (Finland) Author West, John A. School of Biosciences 2, University of Melbourne, Parkville VIC 3010 (Australia) Author Ganesan, E. K. Oceanographic Institute, Universidad de Oriente, Cumaná (Venezuela) Author Yasmin, Farishta Nowgong College, Botany Department, Nagaon, 782001, Assam (India) Author Lim, Phaik-Eem Institute of Ocean and Earth Sciences (IOES), University of Malaya (Malaysia) Author Necchi, Orlando Jr São Paulo State University, Zoology and Botany Department, Cristóvão Colombo, 2265, 15054 - 000 São José Rio Preto, São Paulo (Brazil) o. necchi @ unesp. br (corresponding author) necchi@unesp.br text Cryptogamie, Bryologie 2021 2021-06-04 20 8 93 127 http://dx.doi.org/10.5252/cryptogamie-algologie2021v42a8 journal article 10.5252/cryptogamie-algologie2021v42a8 12297c54-d5a9-4834-8ffd-96de1009b1b1 1776-0992 7828571 Sirodotia cryptica Necchi, N.L.Rossignolo & M.O.Paiano , sp. nov. ( Fig. 4 F-J) TYPE . — F . R . Borges, 15.IV.2014 , ( SJRP [ SJRP 32575]). TYPE LOCALITY . — Brazil , Goiás , Highway GO-070, between the municipalities of Jussara and Itaberaí ; 16°00’32.7”S , 48°55’55.9”W . ADDITIONAL SPECIMENS EXAMINED. — SJRP 31923 and SJRP 31925 ( Appendix 1 ). ETYMOLOGY. — The species epithet indicates that the alga is cryptic with another species described in this study ( S. amazonica Necchi, N.L.Rossignolo & M.O.Paiano , sp. nov. ). DISTRIBUTION. — South America, Brazil (midwestern). REPRESENTATIVE DNA SEQUENCES. — COI-5P (KF010488, KF010491, MW053463,), rbc L (KC951865, KC951869, MW053479) and LSU (MW053494, MW053495, MW053498). Description Plants monoecious or dioecious; whorls 223-559 µm in diameter; primary fascicles (4-)5-10(-11) cells; proximal cells cylindrical or ellipsoidal; distal cells spherical, ellipsoidal or obovoidal; secondary fascicles abundant, covering the entire internode; spermatangia spherical or obovoidal, 1-3 in a group, few or abundant on primary or secondary fascicles, 6-9 µm in diameter; carpogonial branches composed of 1-4 disc- or barrel shaped cells, arising from periaxial, proximal or median cells of primary fascicles, rarely on the secondary fascicles or cortical filaments, short, 10-25 µm long; carpogonia with sessile, elongate cylindrical (with wavy margins), elongate-conical or fusiform trichogynes, sometimes with anomalous shapes (bent end), (24-)26-58 µm in length, 9-13(-15) µm in diameter; gonimoblast initial developing from the protuberant side of the carpogonium; gonimoblast filaments prostrate with erect branches of 2-5 cells; carposporangia subspherical, ellipsoidal or obovoidal, 10-17 µm in length, (7-)8-11 µm in diameter. Remarks This species is morphologically indistinguishable from S. amazonica Necchi, N.L.Rossignolo & M.O.Paiano , sp. nov. that also occurs in Brazil , but is genetically divergence and thus, it is here described as a new species.