Bry. Eur. fasc. 25–28. 1845. -- Grimmia conferta Funck, Deutschl. Moose 18. 1820. -- Schistidium apocarpum var. confertum (Funck) C. Muell. -- Grimmia apocarpa var. conferta (Funck) Spreng. in Linn., Syst. Veg. 4(1): 153. 1827.
Plants to 1.5 cm high, in brownish-green, often somewhat reddened cushions, brownish below. Leaves lanceolate and broadened immediately above the base, 3–3.5: 1, imbricate when dry, erect-spreading when moist, somewhat concave proximally and sharply keeled distally, to 2 mm long with the awn absent or very short. Median leaf cells in very regular longitudinal rows, unistratose throughout or with a few bistratose streaks, smooth, 6–8 µm wide, isodiametric and rather thick-walled (lumen: wall ratio about 3–4: 1 with lumens regular but with prominent corner thickenings. Marginal cells not differentiated. Basal juxtacostal cells rectangular and rather thin-walled, to 3: 1, to 10 µm wide, with lateral walls straight. Cells of alar region, quadrate to very short rectangular with lateral walls thin but transverse walls markedly more thickened. Costa filling about 1/10 of immediate leaf base, not tapered above, percurrent. Costa cross-section at leaf middle about 3 cells thick, with only 2 cells exposed on adaxial surface and about 10 cells exposed on abaxial surface. Leaf margin recurved from immediately above leaf base to very near the apex. Awn of vegetative leaves seldom present but usually only a few cells long, decurrent and flat, sharply serrulate to serrate on its entire surface. Axillary hairs to 300 µm long, with 6–8 rectangular, thin cells with straight lateral walls, without a basal brown cell. Rhizoids red brown and monopodially branched, to 20 µm wide at base, smooth to finely verruculose. Stem cross-section round without a central strand or with that strand inconspicuous. with stereome only gradually differentiated from the somewhat pachydermous, hyaline inner cortical cells.
Autoicous with perigonia located on separate branches similar to those with the perichaetia. Perichaetial leaves closely sheathing capsule, mostly a little longer than adjacent vegetative leaves with awn present even when absent on vegetative leaves. Seta to 0.5 mm long, yellow to pale brown, straight and smooth. Urn immersed, erect, symmetrical and cylindric, 1–1.5: 1 when operculate, smooth when dry, to 1.25 mm long, not strumose. Operculum with only a short apiculus, about 0.2 mm long. Annulus absent or indistinct. Calyptra mitrate, lacerate basally, covering only operculum Peristome to 300 µm long, coarsely papillose proximally, strongly and asymmetrically cribrose. Suboral exothecial cells reddened, thick-walled with lumen: wall ratio about 1–2: 1, transversely elongate, to 20 µm wide, about 0.3–0.5: 1. Median exothecial cells rather regular in size and shape, 25–35 µm wide, in regular vertical rows, quadrate, thick-walled with lumen: wall 4–5: 1. Stomata absent. Spores smooth, to 10 µm.
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