Tortella tortuosa
Tortella rigens
tortured tortella moss
tortella moss
leaves rather soft, uniform in size, strongly crisped or contorted with spirally curled tips when dry, flexuose- to widespreading when moist, long-lanceolate to linear-lanceolate, broadly to narrowly concave or nearly plane proximally to more or less keeled in the apical region, (2–)3–6.5(–7) mm;
base somewhat broader than limb, oblong;
margins usually shortly and strongly undulate, evenly crenulate-papillose, gradually subulate-acuminate, apex acumination confluent with the mucro, leaves at the extreme stem apex surmounted by a stout, multicellular mucro;
costa excurrent as a long, smooth or denticulate mucro or short awn, usually composed of 5–10 rhomboidal cells, adaxial cells of the costa variable, costa distal to the leaf base to the distal median region covered by an epidermis of quadrate to short-rectangular (2:1) papillose cells, in the distal adaxial region variously with a narrow or broader central groove of exposed, smooth, elongate (8:1) stereid cells, occasionally the groove conspicuous and extensive;
proximal laminal cells abruptly differentiated from distal cells, hyaline, laxly thin-walled;
distal laminal cells 1-stratose, quadrate, 7–10(–13) µm wide, marginal cells undifferentiated.
1–3 cm, rarely to 4 cm, densely foliose, leaf bases not evident between the leaves, central strand absent, tomentum rufous, dense, visible between the leaf bases especially along the lower stem.;
stem leaves firm, somewhat rigid, stiffly erect, especially proximal leaves, to loosely twisted and moderately contorted when dry, erect and somewhat spreading when moist, gradually larger and more crowded toward the stem tips, distal-most leaves usually more spreading than the erect leaves or leaf bases proximally;
leaf shape variable within clumps and on the same stem: short stems with leaves short, ovate-lanceolate, margins inwardly tapering to acute apices, longer stems with longer, more narrowly lanceolate leaves with more acuminate apices, the proximal leaves frequently narrowly lanceolate, distal leaves ovate or broadly ovate-lanceolate, generally narrowing gradually, but often some distal-most leaves with an abrupt narrowing with parallel sides in the distal quarter, leaf tips fragile, the older ones usually eroded; deeply concave to canaliculate-tubulose in longer leaves, 1.5–3(–4) mm;
base undifferentiated in shape to broadly ovate proximally narrowing gradually or abruptly to the lanceolate distal lamina;
margins variously plane, erect, to incurved, infrequently undulate in some leaves, apex fragile, acute to acuminate, abruptly ending before a sharp apiculus or narrowly acute and confluent with a conical, nearly mucronate apiculus; in shorter leaves naviculate to nearly cucullate, distinctly cucullate in the awl-shaped youngest leaves arising from the stem apex;
longer, narrow leaves with erect to broadly incurved margins extending to the leaf apex;
costa short-excurrent into a sharp, narrow, denticulate or smoothly conical mucro of 1–5(–10) cells, adaxial surface covered by quadrate, papillose laminal cells except for a narrow groove of elongate (8:1) smooth cells continuous throughout length of the leaf, in cross section, adaxial epidermal cells interrupted in the center, exposing the adaxial stereid layer by about two cells;
proximal laminal cells abruptly differentiated from distal cells, yellow-hyaline, elongate, 6–8:1, firm to laxly thin-walled, smooth;
marginal angle of differentiated cells steep due to the quadrate laminal cells extending juxtacostally far down into the proximal cell region, with a marginal row of firm to thin-walled, quadrate to short-rectangular smooth cells extending a short way up the lamina or to mid-leaf;
distal laminal cells frequently 2-stratose on one or both laminae juxtacostally or extending marginward as one to two pairs of cells, but never extending to the margins even in longer leaves with narrowed apices, rounded-quadrate or hexagonal, with slightly thickened walls, (12–)14(–17) µm wide, strongly papillose, areolation more or less distinct, differentiated distal marginal cells absent except in longer leaves possessing a somewhat differentiated and deciduous apex, these having obscure (due to erosion) to distinct thicker-walled, less papillose to smooth, elongate marginal cells.
0.9–2.7(–3.5) cm.
dioicous, but seldom fruiting; perigoniate plants rare;
perigonia apparently few per stem, inner perigonial bracts ovate and abruptly apiculate, scarcely longer than the antheridia, 0.5 mm; perichaetiate plants common;
perichaetia numerous on the stem;
perichaetial leaves differentiated even in unfertilized perichaetia, slender and erect at the base, long, 5–5.5 mm, somewhat sheathing, distal part, consisting mostly of costa, setaceous-subulate, erect, in fertile plants, stiff and slightly flexuose, distinct and conspicuous above the tightly crisped cauline leaves when dry.
apparently dioicous: only sterile and perichaetiate plants seen.
1.5–3.3 mm;
annulus not vesiculose;
operculum 1.5–2 mm;
peristome teeth long and spirally wound 2 or 3 times, 1.1–1.4 mm.
asexual reproduction none except possibly through fragility of the lamina in some populations, or weakness toward the apex.
asexual reproduction apparently by means of fragile leaf tips in the longer leaves.
terminal, leaves long-lanceolate, costa excurrent into a long awn or subula.
unknown.
Tortella tortuosa
Tortella rigens
Varieties ca. 20 (3 in the flora).
(Discussion copyrighted by Flora of North America; reprinted with permission.)
Tortella rigens is known in Europe from the alvars of the circum-Baltic states and central Europe. In North America, alvars appear confined to substrates of Ordovician and Silurian limestones and dolomites, being areas of exposed rock adjacent to bodies of water. The exposures occur around the Great Lakes and St. Lawrence River and associated lakes, such as Lake Simcoe in Ontario and Lake Champlain in New York and Vermont. The epithet refers to the somewhat rigid character of the leaves (but not as rigid as in T. fragilis). The proximal stem leaves when dry, however, may be as rigidly erect and straight as those of T. fragilis. Tortella rigens may have an adaxial epidermis in the proximal part of the leaf and the adaxial stereid layer is less exposed (usually by two stereid cells), hence there is a somewhat more narrow groove or channel running the length of the leaf. Tortella inclinata var. inclinata is regularly cucullate whereas T. rigens is distinctly cucullate usually only in the smallest leaves or on the smallest stems, or in the first whorl of leaves at the stem base. The leaf apices of T. inclinata var. inclinata may be acute to narrowly so, the distal laminal cells, however, are only 10–12 µm, while in section, the leaves are not 2-stratose juxtacostally, the leaves keeled beside the costa and broadly incurved distally. Tortella rigens has 2-stratose cells juxtacostally in the median portion of the leaf, and therefore the laminae spread out in a broadly concave leaf cross section, the distal cells 14 µm or more in width. Although T. rigens was not recorded as part of the Canadian flora by R. R. Ireland et al. (1987), it does appear in the most recent checklist of North American mosses (L. E. Anderson et al. 1990). The species has previously been reported from Colorado by W. A. Weber (1973), but several specimens collected and determined as that species can be assigned to other species, mainly T. alpicola and depauperate plants of T. fragilis. The cells sizes are undoubtedly large in T. rigens, to 14 or rarely 17 µm, but sizes to 14 µm correlated with reduced apical propagula can be demonstrated in T. fragilis.
(Discussion copyrighted by Flora of North America; reprinted with permission.)
1. Plants red-green, appearing black proximally, densely foliose with a thick apical coma, leaf bases hidden; stems appearing atomentose but tomentum hidden in the bases of branch innovations; leaves not fragile, intact; leaves often strongly squarrose-recurved when wet, plane, not undulate; proximal laminal cells thick-walled and brownish, intergrading in shape and size with the distal cells, which are often nonpapillose in the area of merger; leaves broadly concave in section; costa at midleaf exposed adaxially by as much as four stereid cells | var. arctica |
1. Plants green or yellow-green, appearing brown proximally, loosely foliose, some leaf bases exposed, only slightly comose at stem apex; stems conspicuously tomentose; leaves fragile or not, erect- to erect-spreading when wet; undulate or plane; proximal laminal cells thin-walled and hyaline, sharply differentiated in shape and size from the papillose distal cells, which are papillose in the area of contact; leaves keeled in section, costa in apical region exposed adaxially by up to 2 stereid cells in width or completely covered with an adaxial epidermis of quadrate papillose cells | → 2 |
2. Leaves in tight, complex spirals when dry, appearing soft or lax throughout the stem length, not fragile or erose, leaf tips nearly all present; conspicuously undulate; leaf cross section without 2-stratose areas beside the costa, the lamina uniformly 1-stratose, lamina intact, the costa always differentiated into guide cells, stereids and epidermal cells, adaxial stereid layer never disappearing toward the apex, adaxial epidermal layer typically absent apically in a medial groove to two stereid cells in width. | var. tortuosa |
2. Leaves in loose, simple spirals or once circinate when dry, appearing firm or rigid, often fragile and erose, leaf tips often absent; inconspicuously undulate, especially when dry; leaf cross section with 2-stratose areas beside the costa, the lamina irregularly 2-stratose in patches, lamina tattered, costa occasionally appearing undifferentiated in apical region of the leaf, adaxial stereid layer occasionally disappearing toward the apex, epidermal layer may be continuous throughout the leaf length. | var. fragilifolia |
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