Herposiphonia subdisticha Okamura 1899

    Thalli firm and intensively branched, light brownish red to dark brown; thalli attached to substratum by unicellular heptera (rhizoid) with digitate base; prostrate indeterminate axes terete, with upwardly curved (circinate) apices measures 110-155 µm in diameter; prostrate indeterminate branches consist of 10-11 pericentral cells and each segment measures 100-190 µm in length; prostrate indeterminate axes produce erect indeterminate and determinate branches on each segment; thallus shows typical distichous or nearly distichous branching pattern; determinate branches terete with blunt apices and narrow at the base, determinate branches with 8–9 pericentral cells, branches slightly or strongly curve towards the tip; determinate branch 50–80 μm in diameter and comprise of 8- 19 segments; 8 pericentral cells at the basal segments.

    Carposporophyte 250-600μm long , 200-550μm broad; carpospores clavate to subclavate, 30-40 μm in length and 12-18 μm breadth; tetrasporangia occur as a straight series of 3–7 on determinate branches, tetrasporangia are borne on short indeterminate branches that arise from the main axes, tetrasporangia, tetrahedral 60-85µm in length and 80-105 μm in breadth.