| Diagnosis |
Colony composed of a discoidal hydrorhiza giving rise to an erect, branched stem ca 7.5 cm high and polysiphonic over almost its total length. Stem giving rise to branches irregularly arranged in approximately one plane, sometimes with alternate arrangement. Some branches distinctively longer, also polysiphonic and bearing lower order branches. Hydrothecal
internodes either straight or slightly geniculate. Hydrothecae alternately arranged in one plane; usually one hydrotheca per internode. Occasionally, however, internodes with two hydrothecae present, though in this situation second hydrotheca situated at the place usually
occupied by the gonothecae. Hydrotheca cylindrical, but markedly curved abcaudally. Adcauline hydrothecal wall typically adnate to internode for more than half its length. Free part of adcauline wall straight or slightly convex. Abcauline wall concave. Cusps of hydrothecal aperture sharp, separated by deep embayments. Hydrothecal rim with numerous renovations. |