Table 2 in Two new freshwater species of the genus Achnanthidium (Bacillariophyta, Achnanthidiaceae) from Qingxi River, China

Table 2. Comparison of morphological characteristics of Achnanthidium qingxiensis sp. nov. and closely related taxa. Species/FeatureA. qingxiensis sp. nov.A. sublanceolatum Yu, You & WangA. linannulumm Karthick, Taylor & HamiltonA. sinense Liu & BlancoA. gracillimum (Meister) MayamaA. chitrakootense WojtalValve length (μm)22.5-2818-3515.5-32.517.5-31.719-31.513-42Valve width (μm)3.8-4.64-4.52.5-4.54.1-6.03-43.4-4.2Valve outlineLinear-lanceolateLinear-lanceolateLinear elliptical to lanceolateNarrow lanceolateElliptical to lanceolateLinear to linear-ellipticalValve apicesRoundedRounded or weakly protractedRounded or slightly protactedNot protracted, acute roundNarrowly rostrate to subcapitateSubcapitate to roundedRaphe valveAxial areaNarrow, linear-lanceolateNarrow, linear-lanceolateLanceolateNarrow lanceolateLinearlinear-lanceolateCentral areaAbsentAbsentIndistinct to weakly expandedRhombic-lanceolateAsymmetricalIndistinct to weakly expandedRapheSlightly undulate, distal raphe ends deflected towards the same side, internally proximal raphe endings weakly deflected in opposite directionsDistal raphe fissures deflected to the same side, internally proximal raphe fissures weakly deflected in opposite directionDistal fissures deflected to the same side at an ange of 80-90°, internally proximal ends curved in opposite directionsRaphe distal raphe ends curved to the same side, internally proximal raphe endings curved towards opposite sideDistal raphe fissures are sharply bent, internally central raphe ends curve to opposite sidesDistal raphe ends strongly curved to the same side, proximal raphe ends with slightly defl ected to opposite sidesDensity of striae (10 μm)21-25 (middle), 42-44 (apices)20-23 (middle), 34-42 (apices)24-27 (middle), 32-34 (apices)21-28 (middle), 40 (apices)22 (middle), 36 (apices)26-30Number of areolae per stria5-8 (middle), 1-3 (apices)3-4 (middle), 1-2 (apices)2-35-6 (middle), 1-3 (apices)4-5 (middle), 1-2 (apices)2-4 (middle), 1-3 (apices)Rapheless valveAxial areaLinearNarrow linear-lanceolateNarrow lanceolateLinearLinearLinearCentral areaAbsentAbsentWeakly expanded to absentAbsentWeakly expanded to absentAbsentDensity of striae (10 μm)20-24 (middle), 32-34 (apices)21-24 (middle), 30-36 (apices)24-26 (middle), 28-30 (apices)21-27 (middle), 34 (apices)22 (middle), 36 (apices)26-30Number of areolae per stria5-10 (middle), 1-4 (apices)2-5 (middle), 1-2 (apices)2-46-7 (middle), 1-3 (apices)4-5 (middle), 1-3 (apices)4-5 (middle), 2-4 (apices)ReferencesCurrent studyYu et al. (2019a)Karthick et al. (2017)Liu et al. (2016)Kobayasi et al. (2006)Wojtal et al. (2010)