Plants small to large, in loose to dense mats, green to yellowish (golden) or brownish. Stems creeping, densely foliate, often julaceous, irregularly and usually sympodially branched, branches similar to stems; central strand present; pseudoparaphyllia triangular, acute; axillary hairs of 2–4 cells, cells long, 3–6:1. Stem leaves appressed (erect when moist in S. californicum and S. julaceum), usually closely imbricate, broadly ovate to ovate-lanceolate, strongly concave, not plicate; base inconspicuously decurrent; margins serrulate to subentire; apex gradually or abruptly tapered, obtuse, acute, short–acuminate, apiculate, or rarely long-acuminate; costa to 60–80% leaf length, moderate to somewhat stout, terminal abaxial spine usually present, indistinct (absent in S. obtusifolium); alar cells isodiametric, small to enlarged, walls thin to thick, region triangular, small or reaching 100% distance to costa; laminal cells flexuose-linear, walls thick; basal cells short to elongate. Branch leaves similar. Sexual condition dioicous; perichaetial leaf acumen long, reflexed. Seta red-brown, rough throughout or distally, or smooth. Capsule inclined to horizontal (suberect to inclined in S. cespitans), red-brown, short-cylindric, usually curved; annulus separating or not; operculum conic; peristome xerocastique, perfect. Calyptra naked. Spores 10–19 µm.

Distribution

w North America, nw Mexico, w Eurasia, n Africa, Atlantic Islands.

Discussion

Species 6–10 (6 in the flora).

The taxonomic status of East Asian and Australian species within Scleropodium needs confirmation. In the flora area, plants of Scleropodium are glossy; the endostome cilia are appendiculate (or rarely nodose in S. cespitans). The thick-walled basal laminal cells sometimes make the leaf difficult to detach.

Selected References

Lawton, E. 1967. Notes on Scleropodium, with the description of a new species. Bull. Torrey Bot. Club 94: 21–25.

Lower Taxa

Scleropodium californicum, Scleropodium cespitans, Scleropodium julaceum, Scleropodium obtusifolium, Scleropodium occidentale, Scleropodium touretii

Key

1	Plants small to medium-sized; leaves 0.3-0.8 mm wide	> 2
1	Plants medium-sized to large; leaves usually 0.6-1 mm wide	> 4
2	Leaf apices narrowly acute to acuminate, at least some apices long-acute to moderately long-acuminate; leaves 0.8-1.2 × 0.3-0.4(-0.5) mm.	Scleropodium californicum
2	Leaf apices obtuse, acute, or very short-acuminate; leaves 0.7-1.6 × 0.3-0.8 mm	> 3
3	Branches strongly julaceous; leafy shoots 0.3-0.4 mm wide; leaf apices broadly acute or obtuse; leaves 0.7-0.9(-1.2) × 0.5-0.6(-0.7) mm, length to width ratio usually1.2-1.5:1.	Scleropodium julaceum
3	Branches moderately or sometimes strongly julaceous; leafy shoots (0.4-)0.6-0.9 mm wide; leaf apices acute or short-acuminate; leaves 0.8-1.6 × 0.3-0.8 mm, length to width ratio 1.6-2.6:1.	Scleropodium cespitans
4	Leaf margins serrulate at apex	> 5
4	Leaf margins entire, occasionally minutely serrulate at apex	> 6
5	Basal laminal cells quadrate to short-rectangular; plants medium-sized; leaves 0.3-0.8 mm wide.	Scleropodium cespitans
5	Basal laminal cells elongate; plants medium-sized to large; leaves (0.3-)0.6-1(-1.2) mm wide.	Scleropodium touretii
6	Stem leaf apices obtuse or shortly apiculate; costal terminal spine absent.	Scleropodium obtusifolium
6	Stem leaf apices acute to rounded or cuspidate, occasionally acuminate; costal terminal spine present.	Scleropodium occidentale