BFNA Title: Pseudoscleropodium
PSEUDOSCLEROPODIUM - BRACHYTHECIACEAE
XX. PSEUDOSCLEROPODIUM (Limpricht) Fleischer in Brotherus, Nat. Pfl. 11: 394. 1925 * [Greek pseudos, false, and the moss genus Scleropodium]
W. B. Schofield
Scleropodium sect. Pseudoscleropodium Limpricht, Laubm. Deutschl. 3: 142, 1896
Plants robust, in loose soft, yellowish-green to golden-green mats, reclining to suberect. Leafy shoots and branches julaceous, regularly to irregularly pinnately branched, 2--15 cm, branches 1--3 cm, lacking rhizoids. Leaves crowded and imbricate to loosely erect, incurved, weakly plicate when dry, broadly ovate to oblong, stem leaves 2--2.5 mm, branch leaves 1--2 mm, rounded obtuse and with abruptly reflexed apiculus, margins plane, entire to weakly toothed, costa single, slender; laminal cells linear-flexuose, smooth, 50--80 \um (10:1). Sexual condition dioicous. Seta brown when mature, smooth, 2--5 cm. Perichaetial leaves ecostate, the inner ovate-lanceolate, subulate-acuminate, erect, sheathing the seta. Capsule inclined to pendulous, oblong-cylindric; annulus well-defined, of 2 rows of cells; operculum blunt conic; peristome double, exostome of 16 lance-subulate red-brown teeth, endostome pale yellow-brown, finely papillose, with high basal membrane, cilia appendiculate in groups of 2 or 3. Calyptra cucullate, smooth. Spores 11--13 \um, spherical, smooth to finely roughened.
Species 1 (1 in flora): native to Europe but introduced widely, e, w North America, West Indies (Jamaica), South America, Europe, n Africa, Asia (Japan, Sri Lanka),Atlantic Islands (Azores, Canary Islands, Iceland, Madeira, St. Helena, Tristan da Cunha), Indian Ocean Islands (Reunion), Pacific Islands (Hawaii).
1. Pseudoscleropodium purum (Hedwig) Fleischer ex Brotherus, Nat. Pfl. ed. 2, 2: 294, l925
Hypnum purum Hedwig, Sp. Musc. Frond., 253. 1801; Scleropodium purum (Hedwig) Limpricht in Rabenhorst
Plants forming carpets or turfs, regularly
pinnate in protected sites, irregularly branching in regularly mowed
lawns. Sporophytes unknown in
Lawns of urban areas and in cemeteries, tolerant of lawn-mowing, sometimes flourishing at forest edges where discarded with lawn clippings; tolerant of 2--3 months of summer drying, flourishing in winter; low to moderate elevations; B.C., Miquelon, Nfld., N.S.; Maine, Mass., Mich., N.H., N.Y., Ore., Wash.
Pseudoscleropodium purum is considered a troublesome lawn-weed on the Pacific coast, leading to a thriving “moss-killer” industry. It is always in anthropogenic habitats, and was probably introduced in packing material for nursery stock, possibly disseminated inadvertently from one lawn to another by professional lawn-care workers. Additional information on this unusual moss has been presented by E. Lawton (1960), N. G. Miller (2000), N. G. Miller and N. Trigoboff (2001).
REFERENCES Lawton, E. 1960. Pseudoscleropodium purum in the