TABLE 1 in Two new species of Achnanthidium Kützing (Achnanthidiaceae) from the Quaternary sediments of the Colônia basin, Southeast Brazil

TABLE 1. — Morphometric data from Achnanthidium ectorianum Marquardt & C.E.Wetzel, sp. nov. populations found in the Colônia basin, São Paulo, Brazil, and the most similar taxa belonging to the A. minutissimum complex.
A. anatolicumAchnanthidium ectorianumC.N.Solak, Wojtal,Marquardt & C.E.Wetzel,A. neotropicumS.Blanco, Peszek &sp. nov.K.J.Krahn & C.E.WetzelA. lailae van de VijverM.RybakReferencethis studyKrahn et al. (2018)Van de Vijver & KopalováSolak et al. (2022)(2014)Valve outlinelinear-elliptical, with almostlinear to linear-lanceolate,linear to very slightly linear- linearparallel marginsparallel margins, partiallylanceolateconstrictedValve apicesbroadly rounded,broadly rounded,non-protracted, broadlysubcapitatesubrostratesubrostraterounded, never rostrateor capitateLength (µm)10.5-15.56.7-23.410-1411.5-23.0Width (µm)2.5-3.02.0-3.01.8-2.52.5-3.5Girdle viewnarrow, rectangular, bentrectangular, bent withnarrow, rectangular, bentunbentwith weakly recurvedrecurved apiceswith weakly recurvedapicesapicesRaphe valveAxial areanarrow and linear to linear-narrow, slightly wideninglinear to linear-lanceolatevery narrow, slightlylanceolatetowards the central areawidening towards thewidening towards thecentral areacentral areaCentral area‘X’ appearancerectangular fascia orrectangular fasciasmall bordered by 3-4shortened, more widelywidely spaced striaspaced striaeboth sidesTerminal raphestraight, terminating afteralmost straight, small andweakly deflected,fissuresthe last striaedrop shaped, terminating terminating after the lastafter the last striaestriaeStria density (in 10 µm)30-3830-3630-3326-28Areolae openingroundedrounded to elongatedrounded to slit-likerounded to elongatedareolae, sometimes slit-like near the marginsAreolae number2-3, rarely 43-4, rarely 2 in constricted2-34 (5, rarely 2-3 at apices)(at the center)valvesRapheless valveAxial areanarrow and linearlinear to weakly lanceolatelanceolate axial area,narrow and linearwidening near the valvecenterCentral areaabsentalmost absent or irregularelongated, rhombicalmost absentwith shortened, morelanceolate with longerwidely spaced striaemarginal striaeStria density (in 10 µm)32-3630-3628-3027-29Areolae openingrounded to elongated,rounded to slit-like nearrounded to slit-likerounded to elongatedsometimes fused, formingthe marginsa slitAreolae number2-3, rarely 43-42-34-5 (rarely 2, 3 at apices)(at the center)