Schistidium apocarpum
Schistidium tenerum
schistidium moss
schistidium moss
1.2–12 cm, central strand weak or absent.
0.5–2(–4) cm, central strand distinct.
erect or curved, rarely (falcate-) secund when dry, ovate-lanceolate, sharply keeled distally, (1.3–)1.7–2.5(–3.2) mm, 1-stratose or rarely 2-stratose in striae distally;
margins usually recurved throughout or to just before the apex, usually denticulate distally, 1 or 2-stratose;
apices acute or sub-obtuse;
costa percurrent or excurrent as a smooth or weakly denticulate, occasionally decurrent awn, abaxial surface often papillose;
basal marginal cells usually quadrate;
distal laminal cells mostly short-rectangular, 8–10 µm wide, smooth, sinuose.
erect, usually imbricate when dry, ovate-triangular to ovate-lanceolate, keeled distally, concave proximally, (0.7)–0.9–1.5(–1.8) mm, usually unevenly 2-stratose distally;
margins usually recurved, smooth, 1-stratose or 2-stratose;
apices acute;
costa usually long-excurrent as a spinulose-denticulate, usually decurrent, often flexuose awn, smooth;
basal marginal cells quadrate or oblate, sometimes with transverse walls thicker than longitudinal walls, trigonous;
distal laminal cells quadrate, ovate, or short-rectangular, 5–8 µm wide, smooth, weakly sinuose or straight.
autoicous.
dioicous.
dark red or brown, short-cylindric, 0.7–1.3 mm;
exothecial cells usually quadrate, sometimes mixed with short-elongate or oblate cells, thin-walled, usually trigonous;
stomata present;
peristome patent or erect, often twisted, 350–600(–700) µm, red, densely papillose, usually perforated.
dark reddish or orange-brown, cupulate or short-cylindric, 0.6–1.1 mm;
exothecial cells isodiametric or elongate, usually thin-walled;
stomata present;
peristome patent to squarrose, 300–420 µm, orange or light brown, papillose, strongly perforated.
11–14(–19) µm, granulose or smooth.
10–14 µm, verruculose.
Schistidium apocarpum
Schistidium tenerum
Although H. H. Blom (1996) considered Schistidium apocarpum to be restricted in the flora area to the eastern portions of North America, it is more widespread and scattered across the continent. The denticulate leaf margins, papillose abaxial costal surface, short-cylindrical capsules, and the thin-walled, often evenly quadrate exothecial cells are distinguishing characters. The long peristome teeth are also useful in identifying S. apocarpum. In good condition the peristome can only be confused with that of S. trichodon, which differs in the darker, often black color of its plants, the peristome teeth often forming a dome, and the cylindrical capsules that retain the columella.
(Discussion copyrighted by Flora of North America; reprinted with permission.)
The densely compact mats or cushions comprised of thin, wiry stems that readily separate once disturbed characterize Schistidium tenerum. The usually unevenly 2-stratose, ovate-triangular, small laminae tipped with long, often flexuose, spinulose-denticulate awns distinguish it from other species of the genus and similar species of Grimmia. This species is closely related to the larger S. heterophyllum, and differences between the two are discussed under that species. Probably because S. tenerum is usually sterile, many collections of it remain unidentified in collections, or identified as an undetermined species of Grimmia.
(Discussion copyrighted by Flora of North America; reprinted with permission.)
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WildflowerSearch
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