Taxonomic notes on some Cosmarium species (Desmidiaceae, Zygnematophyceae) from Brazil Author Ramos, Geraldo José Peixoto 0000-0003-2089-0461 Programa de Pós-Graduação em Botânica, Universidade Estadual de Feira de Santana, Av. Transnordestina, s / nº, Novo Horizonte, 44036 - 900, Feira de Santana, BA, Brazil. & geraldojpr @ gmail. com; https: // orcid. org / 0000 - 0003 - 2089 - 0461 geraldojpr@gmail.com Author Santos, Maria Aparecida Dos 0000-0001-9354-7192 Programa de Pós-Graduação em Botânica, Universidade Estadual de Feira de Santana, Av. Transnordestina, s / nº, Novo Horizonte, 44036 - 900, Feira de Santana, BA, Brazil. & maria. asbio @ hotmail. com; https: // orcid. org / 0000 - 0001 - 9354 - 7192 maria.asbio@hotmail.com Author Moura, Carlos Wallace Do Nascimento 0000-0001-6904-6603 Programa de Pós-Graduação em Botânica, Universidade Estadual de Feira de Santana, Av. Transnordestina, s / nº, Novo Horizonte, 44036 - 900, Feira de Santana, BA, Brazil. & wallace @ uefs. br; https: // orcid. org / 0000 - 0001 - 6904 - 6603 wallace@uefs.br text Phytotaxa 2021 2021-02-12 483 3 291 299 http://dx.doi.org/10.11646/phytotaxa.483.3.9 journal article 10.11646/phytotaxa.483.3.9 1179-3163 5420996 Cosmarium heptangulare Lacoste de Díaz (1972:212) ( Figs 3 , 22–26 ) Cell dimensions: 18–22 μm long, 18,5–22 μm wide, isthmus 6–7 μm wide. Material examined :— BRAZIL . Pantanal dos Marimbus , Andaraí, Bahia State . Sample: HUEFS 241798 . Habitat: —This taxon was found associated with periphyton of Utricularia foliosa . EC 0.07 (± 0.03 mS cm-1 ), DO 6.6 (± 0.3 mg L- 1 ), pH 6.6 (± 0.6), TDS 0.03 (± 0.01), T 27.6 (± 0.2 ºC), WT 0.7 (± 0.14 m ). Note :—This species was originally described by Lacoste de Díaz (1972) based on samples gathered in Valinhos, São Paulo , Southeastern Brazil . This was the only record of this species till now. Almost 50 years later, it was found again in Brazil , but now in Bahia , Northeast region. The cell outline (7–8 angled), as well as wide and straight apices are the main morphological features of this species. The SEM analysis revealed that the cell wall is slightly scrobiculate (pock marked pattern) ( Fig. 26 ). Another feature which we consider relevant in this species is the apical view, which is oblong. Somewhat similar species such as Cosmarium lapponicum ( Borge 1913:19 ) , and C. fontigenum Nordstedt ( Wittrock & Nordstedt 1878: 71 ) have elliptical cells when observed in apical view.