Pseudoleskeella tectorum |
Leskeaceae |
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pseudoleskeella moss |
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Habit | Plants dark olive green or rarely yellow-green. | Plants in mats or patches, green, golden green, brown-green, or blackish, rarely with orange or red tinge. | ||||||||||||||||||||||||||||||||||||||||||||
Stem(s) | leaves ± catenulate when dry, not homomallous, ovate, abruptly narrowed to apex, concave, not plicate, 0.4–1.2 mm, 1.5–2:1; base flaring; margins plane or rarely recurved proximally, entire; apex short-acuminate, sometimes falcate; costa usually double, or single, 2-fid, or sometimes ecostate, weak, not reaching mid leaf; medial laminal cells 1–2(–3):1, walls firm, not incrassate. |
and branch leaves usually similar, rarely differentiated.; stem leaves appressed to erect when dry, erect to erect-spreading or rarely squarrose when moist, ovate, ovate-lanceolate, or oblong, symmetric or sometimes asymmetric, not to distinctly plicate on either side of costa; margins plane to recurved, entire to serrate distally, limbidium absent or rarely present; apex broadly rounded, acute, or acuminate; ecostate to costa percurrent, sometimes 2-fid, occasionally sinuate distally; alar cells shorter than laminal cells, isodiametric to transversely elongate, region usually distinct; laminal cells isodiametric to elongate-rhomboidal or linear-fusiform, often prosenchymatous, sometimes obscure or opaque, smooth, papillose over lumen, or prorulose distally, walls thin to usually firm or thick, rarely pitted. |
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Branch leaves | ovate to suborbicular, 0.4–0.8 mm; laminal cell walls moderately incrassate. |
often smaller; apex sometimes less acute; costa weaker. |
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Seta | red-brown, 0.1–0.2 cm. |
elongate, thin, straight or somewhat curved, often twisted. |
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Sexual condition | dioicous or autoicous; perigonia budlike, on primary stems; perichaetial leaves on primary stems or rarely secondary branches, differentiated, opaque to translucent, apex longer, more acuminate than stem and branch leaves, costa short to excurrent. |
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Capsule | inclined, subcylindric, asymmetric, 1.5–2.5(–3) mm. |
erect to horizontal, long-exserted, oblong to pyriform, symmetric to asymmetric-curved, smooth; stomata absent or present, phaneropore; annulus absent or present; operculum conic, short- to long-rostrate; peristome double, perfect to variously reduced; exostome teeth lanceolate or linear-lanceolate, lamellae present, sometimes faint or absent, striolate to densely papillose; endostome basal membrane low to high, free or sometimes adherent to exostome at base, segments broad and keeled to linear, sometimes absent, cilia well developed to rudimentary or absent. |
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Calyptra | usually cucullate, small, fugacious, usually smooth. |
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Spores | 10–18 µm. |
smooth to variously roughened. |
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Stoloniferous | leaves broadly ovate or suborbicular. |
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Specialized | asexual reproduction rarely present, of clustered flagelliform branchlets in axils of distal branch leaves. |
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Pseudoleskeella tectorum |
Leskeaceae |
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Phenology | Capsules mature summer. | |||||||||||||||||||||||||||||||||||||||||||||
Habitat | Shaded calcareous rock, shaded tree bases or wood | |||||||||||||||||||||||||||||||||||||||||||||
Elevation | low to high elevations (0-4000 m) (low to high elevations (0-13100 ft)) | |||||||||||||||||||||||||||||||||||||||||||||
Distribution |
AK; AZ; CA; CO; ID; KS; MI; MN; MT; ND; NE; NM; NV; OR; SD; UT; WY; AB; BC; NL; NT; NU; ON; QC; SK; Greenland; Eurasia
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Nearly worldwide except Antarctica |
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Discussion | Pseudoleskeella tectorum is distinguished by the dark green, tightly appressed, catenulate leaves, and weak costa. Thin mats of this species can be become quite extensive over time, covering the faces and overhangs of shaded boulders and cliffs. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Genera ca. 18, species ca. 80 (9 genera, 28 species in the flora). Leskeaceae is a heterogeneous family, with genera exhibiting widely divergent morphologies, and with some taxa more closely related to Anomodontaceae, Pterigynandraceae, and Thuidiaceae (J. R. Spence 1996). Recent molecular studies confirm this phylogenetic heterogeneity (A. M. Gardiner et al. 2005; M. S. Ignatov et al. 2006; D. García-Avila et al. 2009), and suggest that there are at least three distinct groups of core genera, centered around Lescuraea, Leskea, and Pseudoleskeella, respectively. Although there is some merit in recognizing Pseudoleskeaceae, following W. P. Schimper, for Lescuraea, Pseudoleskea, Ptychodium, and Rigodiadelphus, this does not solve the problem of where to place Pseudoleskeella. Morphological and molecular evidence also suggests that Claopodium is near Anomodon, and Leptopterigynandrum near Heterocladium. On the other hand, core Leskeaceae, including Haplocladium, Leskea, and Lindbergia, are phylogenetically closer to Thuidiaceae than to the Pseudoleskeaceae group. A. Vanderpoorten et al. (2003b) have shown that Platylomella, currently in Amblystegiaceae, may be close to the Leskeaceae-Thuidiaceae clade, although its correct placement remains unresolved. The original concepts of Leskeaceae and Thuidiaceae, based on sporophyte characters (W. R. Buck and H. A. Crum 1990), are not supported by either gametophyte morphology or molecular data (Spence; Gardiner et al.). (Discussion copyrighted by Flora of North America; reprinted with permission.) |
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Key |
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Source | FNA vol. 28, p. 365. | FNA vol. 28, p. 340. | ||||||||||||||||||||||||||||||||||||||||||||
Parent taxa | Leskeaceae > Pseudoleskeella | |||||||||||||||||||||||||||||||||||||||||||||
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Synonyms | Hypnum tectorum, Pseudoleskea tectorum | |||||||||||||||||||||||||||||||||||||||||||||
Name authority | (Funck ex Bridel) Kindberg ex Brotherus: in H. G. A. Engler and K. Prantl, Nat. Pflanze n fam. 229[I,3]: 997. (1907) | Schimper | ||||||||||||||||||||||||||||||||||||||||||||
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