Marsupella Dumort.
Marsupella Dumort., Commentat. Bot. 114. 1822.
Type: Marsupella emarginata (Ehrh.) Dumort. (≡Jungermannia emarginata Ehrh.)
Plants firm but usually not rigid, typically erect, at times loosely procumbent, rarely forming cushions, light or deep green to usually brownish or reddish, or purplish red or piceous to black, minute to robust. Branching sparing, usually from lower, smaller-leaved sectors of leafy axes; branches all lateral-intercalary, from middle or ventral end of leaf axil, of 2 types: phototropic and soon becoming larger-leaved, and geotropic, microphyllous and forming stoloniform, root-like axes. Rhizoids lacking from sectors with mature leaves, usually abundant on geotropic axes. Leaves vertical, usually erect-spreading to stiffly, pectinately spreading (in a few taxa scale-like and erect or sheathing), distant to imbricate (but with stem at least in part exposed), transversely oriented, the insertion transverse in dorsal half, the leaf insertions crossing the stem midline dorsally (except subg. Stolonicaulon), the leaves mostly somewhat concave to canaliculate, usually bilobed to 0.15–0.45 (rarely unlobed); lobes usually equal, triangular, blunt or rounded to sharp, entire; marginal cells of lobes and lamina never differentiated, chlorophyllose like others, never decolorate, never forming crenulations or denticulations. Cells with conspicuous, often coarse trigones, the cells usually small, in lobes 8–18 µm, in median sector of lamina 8–15 × 12–22 µm; surface smooth. Oil-bodies (Schuster, 2002a) 2–3(4) per cell, large, finely granular, mostly ovoid or oval. Underleaves completely lacking, the leaf insertions approaching the ventral stem midline.
Dioecious, rarely (but in both of our species) paroecious. Androecia terminal or becoming intercalary, the bracts in 4–12 pairs, not reduced in size, the base strongly ventricose, saccate; antheridia 1–6 per bract, the stalk 1–2-seriate. Gynoecial bracts in (1)2–3 increasingly larger series, the innermost bracts less deeply divided than leaves, ± erect, arising from a ring- or tube-like, fleshy stem-perigynium; bracteoles completely lacking. Perianth short, included within (and ± hidden by) the uppermost bracts, typically a short tube, rarely vestigial and then reduced to lobed vestiges or, rarely, lacking, the perianth subtended by a ± distinct, erect, tubular perigynium; perianth when mature broadly obconic to ovate, delicate, contracted at the plicate mouth, the mouth 4–6(8)-lobed after extrusion of the capsule, the lobes crenulate by projecting cells. Calyptra with sterile archegonia near its base.
Seta short to moderately long, massive or reduced to 8–10 outer + 3–4 inner rows of cells. Capsule spherical to slightly ovoid, usually 4-valved to the base, the wall 2- or 2–3-stratose; outer layer of cells with strongly nodular thickenings on all but short walls; inner layer of cells with weaker nodular thickenings, often tangentially extended as incomplete or complete semiannular bands (in several taxa with semiannular bands common).
Spores very small, 7–15 µm in diam., the wall obscurely papillate or with low, often furcate, vermiform ridges. Elaters 2- or 3–4-spiral.
Key to Species
A genus of 40–45 species, of which two are bipolar and occur in New Zealand (Marsupella sprucei, M. sparsifolia). Other Austral species are M. minutula Hässel of South Georgia (Hässel, 1980b); M. capensis S.W.Arnell of South Africa (Váňa, 1985); M. lacerata (Steph.) Váňa of the Neotropics and South Africa (see Váňa, 2003); M. emarginata (Ehrh.) Dumort. of wide distribution in the Holarctic and also present in Central Africa (Váňa, 1985; see range in Váňa, 2003); and M. miniata (Lindenb. & Gottsche) Grolle (=M. lorentziana Steph., type: Argentina, leg. Lorentz) occurs in the Neotropics with a range that includes northern Argentina (see Váňa, 2003, p. 122). The genus is absent from Antarctica; the report by Chen et al. (1995) of M. boeckii (Austin) Lindb. is actually Lophozia excisa (Bednarek-Ochyra et al., 2000). Schuster (2002a) subdivided the genus into five subgenera; the New Zealand species belong to subg. Marsupella.
Description adapted and modified from Schuster (2002a).
