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BFNA Title: Leucolepis |
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LEUCOLEPIS -
Mniaceae
XXX. LEUCOLEPIS Lindberg, Not. Sällsk. Fauna
Flora Fenn. Förh. 9: 80. 1868 * [Greek leuco,
white, and lepis, scaly, alluding
to hyaline, scale-like stem leaves]
S. G.
Newmaster Plants to 3--8 cm, in loose tufts or carpets,
dark green. Stems 1.5(--2) cm,
reddish brown to black, dendroid, branches clustered distally, spreading and
recurved; rhizoids brown, numerous and matted proximally. Stem and branch leaves
differentiated, slightly crisped when dry, spreading when wet, decurrent;
margins plane, serrate, teeth single, large, of one cell, 1-stratose; costa
single, percurrent, broader proximally, toothed on abaxial surface distally. Specialized asexual reproduction
absent. Sexual condition dioicous.
Perigonial leaves short and broad,
forming rosette around antheridia. Perichaetial
leaves lanceolate, reddish,
hyaline. Seta usually single, rarely
2(--3), red-brown, 4--5 cm, somewhat flexuose, smooth. Capsule pendulous, yellow-brown to dark brown, cylindric, 6--8
mm; stomata confined to neck, cryptoporous; annulus differentiated in 3 rows
of cells; operculum hemispherical; exostome brownish yellow, papillose;
endostome yellow-brown, papillose, basal membrane porose, cilia 2--3. Spores 28--30 \um, papillose,
yellow-green. Species 1:
western Leucolepis is a monotypic genus distinguished by
its dendroid habit and differentiated stem leaves. Morphological (T. Koponen
1968) and cytological (R. J. Lowry 1948; Steere et al. 1954) research support
the split of Leucolepis from Mnium. The chromosome number of Leucolepis is n = 5, whereas Mnium is n = 6, 7, and 12. SELECTED
REFERENCES: Lowry, R. J. 1948. A
cytotaxonomic study of the genus Mnium.
Mem. Torrey Bot. Club 20: 1--42. Koponen, T. 1968. Generic revision of
Mniaceae Mitt. (Bryophyta). Ann. Bot. Fenn. 5: 117--51. Koponen, T., 1974. A
guide to the Mniaceae in 1. Leucolepis acanthoneura (Schwägrichen) Lindberg, Not. Sällsk.
Fauna Flora Fenn. Förh. 9: 81. 1868 Hypnum acanthoneuron Schwägrichen, Sp. Musc. Frond., Suppl.
4, 2(1): 258b. 1829; Leucolepis
menziesii (Hooker) Steere in L. F. Koch; Mnium menziesii (Hooker) Müller Hal. Stem leaves differentiated; proximal and medial
stem leaves distant, closely appressed to stem, elongate-lanceolate,
long-acuminate, 2.5--4 × 0.8--1.2 mm, whitish hyaline, reddish brown
proximally; distal stem leaves subtending branches, ovate-lanceolate,
long-acuminate, 2.5--3 × 1--1.5 mm, mostly chlorophyllose with hyaline apex
and acumen. Branch leaves
ovate-lanceolate, acute, 1.5--2 × 0.8(--2) mm; laminal cells of branch leaves
short-rhombic, sometimes isodiametric, thick-walled, sometimes weakly
collenchymatous, marginal and apical cells elongate, forming a weak border. Capsules
mature spring. Common on moist soil, boulders, rotten logs, tree trunks,
shaded habitats along streams, in lowlands and forests; 0--1000 m; B.C.,
Alaska, Calif., Idaho, Oreg., Wash. The
distinctive dendroid growth form and the recurved branches of Leucolepis acanthoneura gives this
species a palm tree or umbrella-like appearance; it is sometimes called
umbrella moss. Male plants have a distinctive rosette of perigonial leaves.
The epithet “acanthoneura” alludes to spiny teeth on the abaxial surface of
the costa. This species may be found as an epiphyte, particularly on
broadleaf trees, extending up the trunk in moist coastal forests. Climacium dendroides is distinguished
by rhizome-like stem, erect capsules, and shiny, broad, cordate stem leaves.
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