Dioicous, of medium size, dark green-reddish brown. Leaves imbricate when dry and squarrose when wet, overlapping the stem, lobe convex, cordate circular with rounded or somewhat truncate apex, the lower portion of the margins frequently recurved, thus simulating a basal lobe, the margins otherwise flat or somewhat reflexed towards the dorsal face, base cordate, the branches when dry semicylindrical, when wet the leaves also here are squarrose. Marginal cells 12 µ, usually thick walled, cells in the centre of the lobe about 18 µ, basal cells to 27 x 45 µ, trigones large. Oil bodies globose-ellipsoid, 4 x 4-4 x 12 µ, colourless-faintly yellow, composed of small drops. Lobule variable in shape, near the apex of the shoots generally open in the lower parts usually helmet-shaped and twice as long as broad, with a short beak in the lateral margin, frequently with a short arched fold from the median part of the beak and upward, the lower portion of the ventral wall of the lobule impressed. Stylus short, to 6 cells long. Amphigastria 2-4 times broader than the stem, subrotund-obovate, often concave toward the ventral face, margin frequently recurved near the base, bilobed to 1/4-1/3, lobes subacute, often with a broad lateral tooth, sinus acute, insertion line arched. Rhizoids often brownish. Androecia globose-ovate, or often long, with 5-15 pairs of bracts, these with isodiametrical, roundedly polygonal cells with thick walls. Female organs in ± elongated branches, perianth 3-winged, sometimes with up to 3 low ridges on the dorsal surface, ellipsoid, with numerous, often leaf-like pluricellular excrescenses. Rostrum cylindrical, 60-80 µ long and 100 µ broad. Inner bracts obovate, obtuse, with margin entire, lobe sharply conduplicate, median margin frequently dentate-lacinulate. Bracteoles bilobed to 1/3, lobes oblong, concave, some times dentated, apex acute. Sometimes pluricellular rounded gemmae from the margins of the bracts and the upper leaves. Characteristic for this species are the lacinulate lobuli of the female bracts, the 3-keeled perianth with foliate excrescenses, the recurved basal part of the leaves when dry, the dark colour, the squarrose leaves when wet, the brown stem and rhizoids, the shape of the lobules and their beak.