Table 1 in Two new freshwater species of the genus Achnanthidium (Bacillariophyta, Achnanthidiaceae) from Qingxi River, China

Table 1. Comparison of morphological characteristics of Achnanthidium anhuensis sp. nov. and closely related taxa. Species/FeatureA. anhuensis sp. nov.A. initium Karthick, Taylor & HamiltonA. rostropyrenaicum Jüttner & CoxA. pseudoconspicuum (Foged) Jüttner & CoxA. pyrenaicum (Hustedt) KobayasiValve length (μm)13-35.711-25.218-24.512.9-2110-16Valve width (μm)3.5-4.53.1-3.64.3-4.52.9-4.82.5-4Valve outlineLinear-lanceolateLinear-lanceolate to lanceolateLinear-lanceolateLinear-ellipticalLinear-lanceolateValve apicesRounded or weakly protractedRounded to weakly rostrate roundedRostrateRounded or slightly cuneateSlightly drawn-out endsRaphe valveAxial areaNarrow, linear-lanceolateNarrow linearNarrow linearNarrow linearNarrow linearCentral areaRectangular or bow tieAsymmet-rical transverse fasciaSmall and hardly differentiatedNarrow transverse fasciaSmall and hardly differentiatedRapheDistal fissures deflected to the same side, internally proximal raphe fissures distinct deflected in opposite directionDistal fissures deflected to the opposite side at an angle 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 fissures deflected to the opposite side at an angle of 60-80°, internally central raphe ends curve to opposite sidesRaphe distal raphe ends curved to the same side, internally proximal raphe endings curved towards opposite sideDensity of striae (10 μm)18-20 (middle), 26-31 (apices)29-3420-22 (middle), 32 (apices)22-24 (middle), 32 (apices)20-25 (middle), 34-40 (apices)Number of areolae per stria3-6 (middle), 1-3 (apices)2-5 (middle), 1-3 (apices)2-6 (middle), 1-3 (apices)3-5 (middle), 1-3 (apices)No dataRapheless valveAxial areaNarrow linear-lanceolateNarrow linearNarrow linearNarrow linearNarrow linearCentral areaAbsentWeakly elliptical to almost absentAbsentAbsentAbsentDensity of striae (10 μm)16-26 (middle), 22-30 (apices)32-3522 (middle), 28 (apices)20-2420-28 (middle), 32-38 (apices)Number of areolae per stria4-6 (middle), 1-2 (apices)3-5 (middle), 1-3 (apices)4-6 (middle), 1-2 (apices)4-6 (middle), 2-3 (apices)No dataReferencesCurrent studyKarthick et al. (2017)Jüttner et al. (2011)Jüttner and Cox (2011)Kobayashi (1997)