| Diagnosis |
Stems erect, polysiphonic, up to 16 cm high, usually deprived of branches basally. Branching scarce, irregularly pinnate, usually simple and in various planes. Stem and branches sometimes with a few perisarc constrictions. Branches strongly narrowed basally. Perisarc frequently striated. Hydrothecae present over entire length of colony, though only visible in monosiphonic parts. Hydrothecae arranged in decussate verticils of three to six hydrothecae,
forming 6 to 12 longitudinal rows, cylindrical in lateral view, immersed into the branches for ca two-thirds of their volume and adcaudally almost fully adnate. In frontal view hydrotheca cylindrical at upper half, but distinctly widening basally; frequently constricted at about
half its length. Hydrothecal aperture circular and tilted downwards, forming an acute angle with long axis of branches. Rim even, usually with a shallow renovation. Hydrothecae lacking mushroom-shaped diaphragm. Female gonothecae present, originating at hydrothecal base. Gonotheca oval, slightly constricted apically to form a short neck. Gonothecal aperture
laterally depressed as the uneven rim is provided with two lobes, an adcauline and
a much larger abcauline lobe. Gonothecal wall provided with a series of striae. |
