Pseudomarsupidium Herzog
Pseudomarsupidium Herzog, Svensk Bot. Tidskr. 47: 31. 1953.
Type: Pseudomarsupidium piliferum (Steph.) Herzog ex Grolle (≡Marsupidium piliferum Steph.)
Plants relatively soft-textured, dull green to brown to fuscous but never nitid, medium in size; leafy shoots stiffly ascending to erect, determinate, unbranched except toward their bases, arising from a system of creeping, rhizoidous, leafless, freely branched, stoloniform axes that typically form an intricate system of wiry, interwoven, root-like organs. Branches uniformly intercalary, predominantly ventral, sometimes lateral-intercalary and from near ventral bases of lower, reduced lateral leaves. Stems rigid, unpigmented or (Pseudomarsupidium aureocinctum) pigmented, with cortical cells persistent and not collapsing, in surface view usually short-rectangular, in cross section in 1(2) layers, rather ill-defined, weakly to moderately thick-walled (distinctly thickened in P. aureocinctum), a hyaloderm lacking. Leaves ± suberect to obliquely spreading, concave at least basally, asymmetric; apex undivided and entire or bidentate, the teeth short to long and spiniferous; margins entire, the dorsal margin often incurved, the base rather dilated, conspicuously long-decurrent, the ventral margin ± dilated. Cells with walls thin, with trigones distinct, nodose, at times confluent, the cells in median, distal and peripheral sectors isodiametric, the basal cells undifferentiated, not or hardly elongated, without differentiation of a vitta. Oil-bodies mostly 4–11 to 19 per cell, finely granular to coarsely papillose. Underleaves lacking. Asexual reproduction lacking (gemmae never developed).
♂ and ♀ Gametangia on strongly abbreviated intercalary branches lacking vegetative leaves, all or mostly from leafless lower sectors of plant or from stolons. Androecia minute, whitish, the bracts in (1)2–6 pairs small, imbricate, unlobed, ventricose. Gynoecia with 2–3(4) series of progressively larger bracts and bracteoles; innermost series of bracts largest, the apices variable, undivided and tapered to the summit or shallowly 2–3-lobulate and/or dentate to ciliate; bracteoles ± connate on 1 or both sides. Shoot-calyptra present, the wall usually 3–4(5)-layered. Perianth variable: large and then 3–5 times the length of bracts and then conspicuous, ovate to fusiform-elliptical, inflated, bluntly trigonous above, the mouth lobulate-ciliate, or abbreviated but distinct and inflated, or (sometimes in Pseudomarsupidium piliferum) vestigial, sometimes cut to the base into 3 bract-like segments with apices spinose-ciliate.
Capsule ellipsoidal, the wall (3)4–7-stratose; outer layer of with imperfect two-phase development, the longitudinal walls with strong nodule-like thickenings alternating with primary walls either devoid of thickenings or with a few nodular thickenings; innermost layer of cells with semiannular bands, the bands at times forked, at times anastomosing to delimit local fenestrae.
Spores tuberculate or baculate; spore:elater diam. ratio large, 2–4.1:1. Elaters bispiral.
A genus interpreted here in the strict sense, with four species. Pseudomarsupidium piliferum is the only Austral species, occurring in New Zealand, Australia (Tasmania, Victoria, New South Wales), New Caledonia, southern South America, Juan Fernandez and Inaccessible Island. Pseudomarsupidium decipiens (Hook.) Grolle has a widespread distribution, being broadly distributed in the Neotropics (Gradstein et al., 2001) including Brazil (Gradstein and Pinheiro da Costa, 2003), the Antilles, Great Britain, Ireland, NW France, Macronesia, South Africa and north in Africa to the Cameroons and Ethiopia. Pseudomarsupidium crossii (Spruce) J.J.Engel occurs in Colombia and Venezuela and P. aureocinctum (R.M.Schust.) J.J.Engel in Venezuela (see Engel, 2007).
References: Grolle (1972a, rev.; 2003); Schuster (1968b, 1969c, 2002a).
