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BFNA Title:
Clasmatodon |
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XX. CLASMATODON Dale
H. Vitt Plants
small, slender, dull to bright green, in loosely interwoven, straggly
mats. Stems prostrate, creeping, and irregularly branched; branch
foliage similar to that of stem; axillary hairs 4--6-celled, distal cell
obtuse, pale brown; juvenile branch leaves narrowly acute. Stem
leaves ovate to ovate-lanceolate, acute to narrowly obtuse, concave,
imbricate and ± subsecund, little decurrent; margins entire, subentire, to
serrulate in distal 1/2, costa slender, reaching 1/3--2/3\x leaf length,
ending without a spine; basal laminal cells quadrate to subquadrate, shorter
at margins, in many rows, walls thin; laminal cells rhombic to
oblong-rhombic, thin-walled, smooth. Branch leaves similar to stem
leaves. Sexual condition autoicous; perichaetial leaves abruptly
acuminate, erect to flexuose from sheathing base. Seta
reddish, smooth. Capsule erect, narrowly elliptic to oblong, symmetric; annulus of
3--4 rows of small, brown cells, persistent; operculum long-rostrate;
peristome double, of 16 short, slender, unequally 2-fid segments partially
fused to inconspicuous basal membrane; exostome of 16, very short, blunt,
partially fused teeth. Calyptra naked. Spores
14--21 \um, finely roughened. Species 1 (1 in the flora): North America, Clasmatodon
has been variously placed in the Fabroniaceae or the
Myriniaceae, but molecular data strongly suggest a position in the
Brachytheciaceae as a small, epiphytic, monotypic genus with a reduced peristome. 1.
Clasmatodon parvulus (Hampe) Sullivant in A. Gray, Man.
Bot. No. Leskea parvula Hampe, Linnaea 13: 46. 1839; Clasmatodon
parvulus var. rupestris
Lesquereux & James Stems
to 1(--2) cm, branches to 2(--5) mm. Stem leaves 0.4--0.7 x 0.3--0.5 mm;
mid-leaf cells 18--30 X 8 --10 \um. Seta 2--5 mm. Capsule
0.7--1 mm. Tree trunks and bases of trees, often in flood plain
forests, or more rarely on calcareous rocks; 0--400 m; Ala., Ark., Fl., Ga.,
Ill., Ind., Ky., La., Md., Miss., Mo., N.C., Ohio, Okla., Pa., S.C., Tenn.,
Tex., Va., W.Va. Clasmatodon
parvulus is an inconspicuous moss forming small, slender, straggly
mats on tree trunks in the southestern |
