Marsupella Dumort., Commentat. Bot. (Dumortier): 114, 1822.

Bakalin, Vadim, Choi, Seung Se & Park, Seung Jin, 2021, Revision of Gymnomitriaceae (Marchantiophyta) in the Korean Peninsula, PhytoKeys 176, pp. 77-110 : 77

Marsupella Dumort., Commentat. Bot. (Dumortier): 114, 1822.

Description.

Plants forming loose patches, commonly ascending or rarely creeping in habitats with strong insolation and incrusted by soil particles, deeply (deep green, brown-green, brown purple, blackish brown) to pale (yellowish, brownish, greenish and their combinations) colored, merely rigid, varying in size from 0.5 to 2.0 mm wide and 5.0-50.0 mm long. Rhizoids sporadic to solitary, although invariably present in ventral geotropic leafless stolons, colorless to grayish and soft-textured, or rarely and solitary purple and rigid. Stem with common ventral branching and rare lateral branches, with characteristic geotropic stolons present in the majority of taxa; in cross section mostly differentiated into three strata: hyaloderm, scleroderm and inner tissue. Leaves transversely or nearly so inserted, obliquely to erect spreading from sheathing or not sheathing base, concave to canaliculate and strongly conduplicate, divided by evident but not deep sinus into two equal to strongly unequal lobes with rounded to acute apices. Underleaves absent. Cells in the leaf in the most taxa pachydermous with large convex trigones, unequally thickened along margin and having smooth cuticle; oil-bodies few in number, (1-)2-3(-4) per cell, finely granulate to papillose or almost smooth, rarely with central eye. Dioicous. Androecia intercalary, spicate, antheridium stalk biseriate (rarely uniseriate near the base). Perianth short, but always developed, onion-shaped or conical, wider than long, mostly hidden, but rarely emergent from bracts; perigynium well developed, commonly 2-3 times longer than the perianth, with (1-)2 pairs of bracts. Elaters 2-4-spiral, spores brownish, papillose.

Comment.

Marsupella is easily recognized, even in the field, due to characteristic rigid texture, transversely inserted and sheathing stem leaves, absence of underleaves, and hidden perianth. Under the microscope, additional features such as pachydermous leaf cells, defined scleroderm in stem cross section, few oil bodies, and high perigynium are helpful to refer specimens to this genus.

This paper accepts recent emendations for the circumscription of Marsupella , the most valuable being the removal of ‘perianth-less’ taxa (e.g., ' M. commutata ') to Gymnomitrion . Five species were confirmed for this genus in Korean flora and one ( M. sphacelata ) regarded as likely reported erroneously.

In the specimens examined section, we cite only one specimen per locality (or 2 to 3, if they were collected at different elevations) with the intention of economizing space. Only specimens from the Korean Peninsula are cited.