Siphonolejeunea

Epiphytic, monoicous. Asexual reproduction by discoid gemmae produced on abaxial lobe surface. Stems infrequently and irregularly branching; branches emerging from main stem near and ventral to an unmodified lateral leaf, without or with a lobed and foliose collar at base. Leaves distant to contiguous, spreading close to substrate or rising away from substrate, narrowly attached to stem by 1 or 2 cells; lobe ovate to elliptic or cylindric (not in Victoria), entire, rounded or acute at apex; lobule smaller than to equal (not in Victoria) to lobe, elliptic to obovoid, saccate to tubular, fused along basal margin to form a straight (not in Victoria) or arching keel that ends in a slight notch or is continuous with the curve of the lobe margin, free along apical margin, with 1–4 marginal teeth, or rarely entire; tooth furthest from stem unicellular or composed of up to 3 cells; hyaline papilla on the inner surface of the tooth furthest from stem, either at base or at apex, or on margin next to tooth furthest from stem facing stem; cells circular, hexagonal, quadrate or rectangular, smooth, mammillose (not in Victoria) or papillose (not in Victoria), thin-walled, with small trigones, without intermediate thickenings, with 1–several botryoidal to sparingly segmented (not in Victoria) spherical or ellipsoid to fusiform oil bodies. Underleaves present, one for each pair of lateral leaves, V-shaped or obtrapezoid, sessile or with a short stalk; lobes filiform, widely divergent, entire; cells hexagonal or quadrate, thin-walled, with or without small trigones, without intermediate thikenings, with 1–several botryoidal to sparingly segmented (not in Victoria) spherical or ellipsoid to fusiform oil bodies. Perianth pyriform, 5-keeled toward apex, rarely 10-keeled (not in Victoria), rarely papillose (not in Victoria), with a short beak at apex, with or without a long narrow stalk.