Diphasia digitalis (Busk, 1852)

Stems arising from a creeping tubular hydrorhiza; stems short, unbranched, each bearing three to seven pairs of hydrothecae; proximal stem region athecate, long, tubular, perisarc smooth, ending in a strong hinge joint.

Hydrothecae biseriate, paired, one pair on internode, node transverse, often indistinct. Hydrothecae long, tubular, expanding from a narrow base at summit of long infrathecal part of internode, adnate adcauline wall twice to three times length of free wall; free wall convex. Abcauline wall concave, sometimes with a slight proximal bulge. Margin quadrangular, perisarc delicate, a low cusp at summit of a longitudinal frontal pleat extending from base of hydrotheca to margin.

Colour: Colourless to pale brown.