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BFNA Title: Fabroniaceae |
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XX. FABRONIACEAE Raddi Terry T.
McIntosh Plants very small, in green, yellow- or
gray-green, often silky mats. Stems sparsely
and irregularly branched, branches terete-foliate, often erect-ascending,
often sub-julaceous, radiculose in scattered tufts. Leaves ovate to oblong-lanceolate, rarely lanceolate, subulate to
piliferous, rarely blunt, often somewhat concave; margins plane, denticulate, dentate, or ciliate-dentate, rarely entire;
apices acute, acuminate,
or long-acuminate; costa single, 1/3--2/3 leaf
length, sometimes ending in a small spine; basal cells rounded-rhomboidal to rhomboidal, quadrate to
transverse-rectangular in a few rows along margins; alar cells quadrate in
several rows; medial and distal laminal cells rhombic, rhomboidal, or elongate-rhombic,
30--45 x 9--12 \um, smooth;
apical cells linear. Specialized asexual reproduction
apparently by foliose pseudoparaphyllia. Sexual condition autoicous. Seta single, erect, yellowish, smooth. Capsule 0.35--1 mm, often flaring at the mouth with aging, neck short,
wrinkled when old; exothecial cells more or less isodiametric, walls sinuose,
suboral cells transverse-elongate, angular, with straight walls; stomata
present in neck; annulus absent; operculum conic, umbonate to mammillate;
peristome single, rarely absent, incurved when moist, erect-spreading,
sometimes recurved when dry, of 16 teeth usually fused in pairs,
broad-lanceolate, blunt, to 0.36 mm, red-brown, densely papillose-striolate. Calyptra cucullate. Spores 10--16
\um, coarsely papillose or smooth. Genera 5, species ca. 17 (1 genus, 2 species in the flora):
North America, Mexico, West Indies, Central America, South
America, Eurasia, Africa, Atlantic Islands, Pacific
Islands (Hawaii), Australia. 1. FABRONIA
Raddi, Atti dell'Accademia
delle Scienze di Siena 9: 231. 1808. * [For Giovanni Valentino Mattia Fabbroni,
1752--1822, Italian naturalist] Stems prostrate. Leaves loosely appressed when dry, spreading when moist. Capsule ovoid to pyriform. Species ca. 11 (2 in the
flora): North America, Mexico, West Indies, Central America, South
America, Eurasia, Africa, Atlantic Islands, Pacific
Islands (Hawaii), Australia. Fabronia is characterized by its very small
size, ovate to oblong-lanceolate, long-acuminate, usually toothed leaves
tipped with linear cells, rhomboidal laminal cells, and relatively short
costa. However, because of the wide degree of morphological variability,
especially within the F. ciliaris complex, Fabronia is taxonomically difficult. Discussions of Fabronia by H. A. Crum and L. E.
Anderson (1981) and W. R. Buck. (1994) are enlightening with respect to the
problems facing its taxonomy. SELECTED
REFERENCES Buck,
W. R. 1994. Fabroniaceae. In: A. J.
Sharp, H. A. Crum, and P.M. Eckel. 1994. The Moss Flora of 1. Leaves
acute or acuminate, dentate to entire, non-ciliate, teeth consisting of one
cell . . . 1. Fabronia
ciliaris 1. Leaves long-acuminate, ciliate-dentate,
teeth often consisting of more than one cell.............. . . . 2. Fabronia pusilla 1.
Fabronia ciliaris
(Bridel) Bridel, Bryol Univ. 2:171. 1827 Hypnum ciliare Bridel, Musc. Rec. Suppl. 2:155. 1812;
Fabronia ciliaris var. polycarpa (Hooker) W. R. Buck; F. ciliaris var. wrightii (Sullivant ex Sullivant & Lesquereux) W. R. Buck; F. ravenelii Sullivant; F. wrightii Sullivant
Capsules mature summer. Bark of trees and on rock; low to
high elevations; Ariz., Ark., Calif., Colo., Ga., Ind., Kans., Ky., La.,
Mich., Minn., Mo., N.J., N. Mex., N.C., Ohio, Okla., Oreg., Pa., S.C.,
S.Dak., Tenn., Tex., Va., Wis.; Mex.; West Indies; Central America
(Guatemala); South America; Europe; Pacific Islands (Hawaii, Japan, New
Zealand); Australia. This
treatment of Fabronia ciliaris generally
follows that of W. R. Buck (1994) although the varieties delimited there for F.
ciliaris are not applied here though the varietal keys and associated
discussions there are very useful. That work underlines the high degree of
morphological variability within this species. Although many species and
varieties have been described within the concept of F. ciliaris,
examination of the variation between and within populations, especially with
respect to the degree of leaf margin dentition, does not support the
acceptance of most of these taxa. Few of the specimens that were examined
could readily be sorted into any of the three varieties recognized by Buck,
and the identification on a herbarium packet was often not consistent with
the characters exhibited by the specimens within the packet. Thus, it appears
that the interpretation of species or varieties remains subjective. 2. Fabronia pusilla Raddi, Atti Accad. Sci. Sienna 9: 231.
1808 Leaves 0.4--0.85 mm; margins ciliate-dentate, teeth
often of more than one cell; apices acute to long-acuminate; medial laminal
cells 30--45
X 9--12 \um. Capsule 0.5--0.8 mm; peristome to 0.36 mm. Spores 9--14 \um. Capsules mature late spring--summer. Rock. bark at bases of
trees; low to high elevations; B.C., Fabronia
pusilla is
a tiny but beautiful moss, unmistakable because of the long-acuminate and ciliate-dentate
leaves. |
