Tasmanaria monticola Watson & Vervoort, 2001

Hydrorhiza a small bunch of tubes, stem polysiphonic; tubes almost parallel, running almost halfway up stem and branches before becoming monosiphonic.

Hydrocladia on branches pinnate, alternate, about 4 mm apart, up to 20 mm in length, directed upwards at an angle of about 30° to branch from a moderately long elbow-shaped apophysis, a hydrotheca in axil, one halfway between successive hydrocladia and one opposite hydrocladium; a transverse, poorly marked node above axillar hydrotheca. Hydrocladium with a long, curved athecate section above apophysis; hydrocladial nodes few but where present, only as a shallow transverse to oblique constriction in perisarc just distal to hydrothecal pairs.

Hydrothecae biseriate, alternate, almost completely immersed in internode, laterally separate, tubular, narrowing a little behind margin. Walls smooth, perisarc thick, adcauline wall smoothly convex, almost completely adnate, free wall less than one fifth length of adnate part; free wall of branch hydrothecae longer. Base of all hydrothecae sharply recurved into a short, almost horizontal plug of perisarc with downwardly pointed spur, abcauline wall faintly sinuous, a small internal shelf of perisarc opposite adcauline plug; an elliptical scar, thinly infilled with perisarc below adcauline plug in most hydrothecae. Margin of hydrotheca thin, tilted upwards at an angle of about 25° to hydrocladial axis, circular, thin, edentulate; some hydrothecae with a few close submarginal replications from within margin and some with minute internal denticles.

Colour: Pale honey brown.