UC Herbarium: Moss eFlora
Directory       News       Site Map       Home
California Moss eFlora
Previous / Next

Home · List of Genera · Key to Keys · Accepted Names · Synonyms · For Beginners · See also .... Subdivisions of CA  —  Jepson eFlora for CA Vascular Plants  —  Specimen records  —  Elevation by latitude plot  —  Tropicos nomenclature  —  Cal Photos images  —  Bryophyte Flora of North America  —  Google Scholar

Hedwigia ciliata (Hedwig) Palisot de Beauvois [Hedwigiaceae]

Is the margin decurrent? Are the alar cells smooth? Stem cross section? Axillary hairs and pseudoparaphyllia? Exothecial cells, stomata and annulus?

Plants dense mats, green to gray green to almost white, usually with a reddish cast, unbranched but with a single innovation below each perichaetium and thus appearing to have lateral sporophytes. Stems to 10 cm long, with leaves erect spreading to appressed when dry, loosely spreading when moist, usually somewhat secund near branch tips. Leaves to 2.5 mm long, 2–2.5: 1, broadly ovate and deeply concave, gradually contracted from the about the middle to the acute to acuminate hyaline awn. Margins strongly recurved to above the middle, decurrent to the base of the next leaf with the distal portion of the decurrency up to 4 cells wide, papillose crenulate below but serrate to dentate on the usually decurrent awn. Median cells quadrate to short rectangular, to 10 µm wide, to 2: 1, with thick and pitted walls, with 1–4 high papillae which, in at least part of the leaf, are forked to branched. Alar cells mostly smooth, quadrate in a well-defined group of quite green cells, with walls somewhat thicker and more pitted than those of adjacent laminal cells. Basal juxtacostal cells elongate, to 5: 1, often reddish, smooth, strongly pachydermous and pitted. Cells of awn elongate, to 8: 1, smooth or with papillae sparse. Costa absent. Pseudoparaphyllia absent. Longest and most central axillary hairs 4–5 celled, to 120 µm with one basal brown cell, not offset from leaf insertion; lateral axillary hairs shorter and fewer celled. Stem cross-section without a central strand, relatively pachydermous throughout, with only gradual size reduction of the more peripheral cells. Rhizoids red brown to almost black, restricted to the prostrate base of plant, arising from axils of leaves, not at all fasciculate, to 15 µm in diameter, smooth and very thick walled, long but essentially unbranched.
   Autoicous. Perichaetial leaves longer and more narrow than adjacent vegetative leaves, with few to numerous multicellular cilia fringing the margin above the middle. Seta very short to wanting. Urn subglobose, light brown, erect, symmetrical, not sulcate but often strongly wrinkled when dry, broadest near the mouth and at the expanded ring-like base, to 1.5 mm long.
    Exothecial cells at mid urn irregularly quadrate to short rectangular, 1–1.5: 1, irregularly arranged, thin walled, to 25 µm broad. Cells in many horizontal rows at both the base and the mouth of the capsule with very thick and pigmented walls, smaller than the median exothecial cells and more consistently isodiametric. Stomata phaneroporous, restricted to the somewhat expanded neck. Annulus absent. Operculum conic, much shorter than urn, with isodiametric and thick walled cells to its apex. Peristome absent with exothecium inrolled at capsule mouth. Spores with a strong trilete mark, papillose, to 30 µm.

Hedwigia ciliata is abundant on rocks throughout most temperate to arctic portions of North America and Eurasia. In tropical and subtropical latitudes, it is restricted to high elevations, and reappears in moderate abundance in temperate areas of Australia and New Zealand. It is perhaps less abundant in California than in any other humid portion of North America. Here, vertical faces of boulders and outcrops, especially in areas of occasional water drainage, may have large swards of this moss. It grows on these sites, mostly below mats of Pseudobraunia, and it becomes especially abundant in areas of frequent disturbance. Most of the sites on which Hedwigia ciliata appears in California bear evidence of disturbance, and I tentatively propose that it may be one of a large group of mosses that may be recent anthropogenic introductions into the state.

Mail a correction to Paul Wilson ·
LiteratureBuck and Norris 1996; Koch 1950a; Steere et al. 1954; Malcolm et al. 2009.
NotesAlthough frequently reported in the literature as a component of the California moss flora, most if not all Californian material actually represents two different taxa. See narrative under Hedwigia detonsa and Hedwigia stellata in this catalogue. Not yet found in CA but known from OR

Elevation by latitude plot for Hedwigia ciliata
   in California

Generated: Mon Jan 23 11:02:11 2017