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Taxon
Plumularia badia Kirchenpauer, 1876
Nomenclature
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Family: PlumulariidaeGenus: Plumularia
SUMMARY
Hydrorhiza a tangle of narrow tubes entwining substrate.
Colonies ranging from single, branched stems 20 mm high to large clusters of 60 complexly branched stems 240 mm high.
Stems slender, monosiphonic, more or less alternately branched in same plane, lower stem region ahydrocladiate, hydrocaulus of short stems stiff, branching pseudosympodial, almost perpendicular to cauline axis; stems of taller colonies long, flexuous, subdichotomous branching common to second or third order, branches directed acutely upwards, distally truncated. Stem and branch internodes short, smooth, nodes transverse, deeply incised proximally, fading distally, a node below and above origin of each branch, branch apophysis with oblique distal node. Perisarc of stem and branches smooth and thick.
Hydrocladia alternate, short, two on branch internode, in distal region of branch one row sometimes slightly displaced to front of branch with a third above, forming a verticel; hydrocladia backwardly curved, inserted on a long, geniculate, upwardly directed apophysis with a strong oblique distal node; two nematothecae in axil and a mamelon with short neck on apophysis distal to nematothecae. Hydrocladial internodes all hydrothecate, variable in length, node deeply oblique, a weak septum projecting downwards into internode from adcauline wall of hydrotheca.
Hydrotheca deep cup-shaped, centrally placed on shorter internodes, proximal on longer internodes, adcauline wall immersed in internode, posterior wall perpendicular to internode, curved, abcauline at an angle of 30° to internode, wall straight, or with a slight concavity behind margin; margin sinuate, base excavated back into internode.
Nematothecae bithalamic, large, moveable, mesial inferior borne on a low prominence of internode, a deep perisarc-infilled notch in front, basal chamber of nematotheca long, cup foreshortened on adcauline side, not reaching base of hydrotheca; twin laterals similar to mesial, inserted on a prominence behind hydrothecal margin, projecting forward from margin, facing inwards towards axis of internode, cup shallowly excavated on adcauline side. Cauline nematothecae same as laterals, one beside apophysis (often absent) and one in axil, a small mamelon or pore on base of apophysis between nematothecae.
Gonotheca inserted without pedicel in axil of branch apophysis, small, conical, distally truncated, terminal orifice circular, sealed by a thin opercular flap, perisarc very thin.
Colour: Stem and branches of live and preserved specimens shining dark brown to black, hydrocladia whitish, gonothecae transparent white.