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eucladium moss, whorled eucladium, whorled tufa-moss

eucladium moss

Habit Plants small, in dense to deep tufts, turfs or swollen cushions, tufa-forming, bright to dark blue-green distally and pale green to yellowish brown proximally or sometimes throughout, rarely rufous; frequently bleached or whitened and indurated with encrusted lime.
Stems

erect, 0.7–6 cm, leaves often branched in whorls in successive innovations.

slender, branching irregularly, densely foliate in whorls at successive innovations;

transverse section rounded-pentagonal with an irregularly inflated or enlarged hyalodermis and weakly developed sclerodermis;

central strand absent; weakly radiculose, rarely strongly so;

axillary hairs of 5–10 cells, hyaline throughout.

Leaves

1.2–2.5 mm, flat to channeled distally or at mid leaf, in transverse section at mid leaf often tapering from costa to leaf margin because of decreasing size of cells, mucro occasionally ending in a sharp, clear cell;

marginal serrulations projecting from the distal end of cells of the hyaline cells of the leaf base;

costa to 1/3 or more the width of the leaf near the base, basal cells 12–15 µm wide, 2–5:1;

median and distal laminal cells 8–10 µm wide, 1(–2):1, walls rather thick, often irregularly so, large juxtacostally and decreasing in size to the leaf margin, irregular in shape from quadrate to rectangular, 1–2(–3):1, sometimes transversely elongate 2:1, occasionally with transverse walls oblique, marginal cells narrower in places and 2–3:1 occasionally approximating a border;

papillae variously scattered or centered.

appressed and scarcely incurved-contorted when dry, erect-spreading when moist, oblong to mostly linear-lanceolate or linear-subulate, base undifferentiated in shape to occasionally broadened-oblong;

margins plane, entire except for distinctive irregular hollow teeth on shoulder just distal to the base, not bordered;

apex broadly to narrowly acute or subulate;

costa strong, percurrent to shortly excurrent as a stout mucro, in transverse section elliptic;

adaxial surface cells quadrate to elongate, adaxial epidermis present, adaxial stereid band, medial guide cells and abaxial stereid band present, abaxial epidermis sometimes absent, hydroid strand absent;

basal cells sharply differentiated across to the margin where they become narrower, elongate, bulging-rectangular to rhomboidal, hyaline, smooth, lax and thin-walled;

distal laminal cells subquadrate, walls sometimes irregularly thickened, papillae low, indistinct, simple or 2-fid, several per cell.

Seta

yellow to redbrown, not or little twisted.

to 8 mm, single, erect.

Sexual condition

dioicous;

perigonia terminal, interior leaves longlanceolate, similar to those of the stem;

perichaetia terminal, leaves as in stem leaves, ovate-lanceolate, to 2.5 mm and sheathing.

Capsule

0.8–1.8 mm, red-brown when old;

operculum 0.5–0.8 mm;

peristome rudimentary or to 300 µm, yellow to orange, with a low, papillose basal membrane.

erect, symmetrical, yellow-brown, ovoid to cylindrical;

annulus weakly developed, of ca. 2 rows of subvesiculose cells;

operculum obliquely conic-rostrate;

peristome teeth 16, straight or slightly oblique, lanceolate, finely papillose, entire to variously cleft.

Calyptra

ca. 2.5 mm.

cucullate, smooth.

Spores

pale.

8–14 µm, spherical, mostly smooth.

Specialized

asexual reproduction reportedly by rhizoidal brood bodies.

Laminal

KOH color reaction yellow.

Eucladium verticillatum

Eucladium

Phenology Sporophytes infrequent, capsules mature Jun–Aug.
Habitat Dripping calcareous or sometimes granitic rock faces or mortar, around springs, dripping bluffs in calcareous regions
Elevation low to high elevations (0-1900 m) (low to high elevations (0-6200 ft))
Distribution
from FNA
AL; AR; AZ; CA; CO; FL; ID; IL; IN; KS; KY; MI; MO; MS; NM; NV; OH; OK; TN; TX; UT; VA; WA; WI; AB; BC; NF; ON; Mexico; Central America; Bermuda; Europe; Asia; n Africa; s Africa; Atlantic Islands (Macaronesia)
[WildflowerSearch map]
North America; Mexico; Central America; Europe; Asia; Africa
Discussion

Eucladium verticillatum is associated with yearround seepage, possibly the reason that, although the stem may be reduced, the leaves are seldom reduced as they frequently are in drought-tolerant species of the family. The plants are typically a yellow-green, and there is usually a vivid contrast between the pellucid green laminal cells and the clear basal ones. Stem hyalodermis cells are frequently attached to the costa base, and form decurrencies of long and thin-walled cells in the leaf angles when leaves are removed. Gymnostomum and Molendoa are similar plants but differ by blunt apices and subpercurrent costae. Both these genera possess a stem central strand, no hyalodermis, and occasional 2-stratose areas in the lamina. Eucladium may be separated from these taxa and others that may be mistaken for it, such as Hymenostylium and Anoectangium by its highly differentiated bulging or lax, thin-walled basal cells. Assurances in the literature to the contrary, many other taxa also possess serrulate or denticulate leaf-shoulder margins, especially Hymenostylium, while Eucladium may rarely lack such serrulations. Specimens of Eucladium in which the lamina is highly reduced so that the leaves seem entirely costate are included without special rank in the range of variation of the species in North America. The laminal papillae of Hymenostylium are clear, sharp, well-defined; those of Eucladium are low, amorphous or scablike on the lumen surface.

(Discussion copyrighted by Flora of North America; reprinted with permission.)

Species 1.

R. H. Zander (1993) removed Eucladium irroratum (Mitten) Jaeger to the genus Tetracoscinodon, rendering Eucladium monotypic and characterized by absence of stem central strand and sclerodermis, a somewhat enlarged hyalodermis, costa broad in relation to the leaf, plane margins with their peculiar dentition at the leaf shoulder (a condition that may be variable or rarely even absent), and terminal inflorescences. The generic placement is near Trichostomum (Zander). The genus is differentiated from other members of the former tribe Pleuroweisieae by the presence of a peristome, the distinctive serrulations on the proximal leaf margins, and the hyaline, thin-walled and bulging-rectangular differentiated basal cells (Zander 1977).

(Discussion copyrighted by Flora of North America; reprinted with permission.)

Source FNA vol. 27, p. 487. FNA vol. 27, p. 486. Author: Patricia M. Eckel.
Parent taxa Pottiaceae > subfam. Trichostomoideae > Eucladium Pottiaceae > subfam. Trichostomoideae
Subordinate taxa
E. verticillatum
Synonyms Weissia verticillata
Name authority (Bridel) Bruch & Schimper: Bryol. Europ. 1: 93. (1846) Bruch & Schimper: Bryol. Europ. 1: 93. 1846 ,
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