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BFNA Title: Acroporium |
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Acroporium – Sematophyllaceae W. B. Schofield† XX. ACROPORIUM
Mitten, J. Linn. Soc. Bot. 10: 182. 1868 * [Greek acro, top, and poros, pore,
possibly alluding the tubulose points of the branches] Plants slender to robust, with leafy shoots
0.5--6 mm in diameter, in creeping to suberect yellowish to golden yellow
mats. Stems 1--10 cm, irregularly
to regularly pinnately branched, sometimes simple, with main stem and
branches often arching upward to form a turf-like or loose mat; branch and
stem tips often with a penicillate group of abruptly imbricate leaves. Leaves of main stem and branches
similar, imbricate or strongly divergent, sometimes somewhat falcate,
narrowly to broadly ovate-lanceolate, 0.5--4.0 mm, acute to acuminate with
distal margins incurved to form a tubulose apex; costa double or absent; leaf
cells smooth or rarely 1-papillose; alar cells 3--5 in 1 row, inflated, often
colored, elongate with associated short cells distally. Specialized
asexual reproduction rare, by filamentous gemmae. Sexual
condition synoicous, autoicous, dioicous or phyllodioicous; perigonia on
branches; perichaetia on stems or branches. Seta red, papillose or smooth, 0.5--2 cm. Capsule erect to inclined (occasionally nodding), ovoid to
cylindric, exothecial cells collenchymatous, operculum finely rostrate from
conic base; exostome of 16 lanceolate, finely striate and longitudinally
furrowed teeth; endostome segments from wide basal membrane, equal to the
length of exostome teeth, cilia single, short, occasionally rudimentary. Calyptra
cucullate, smooth. Spores spherical,
smooth to finely papillose. Species about
60 (1 in the flora); tropical and subtropical, predominantly
Indo-Malesian; se North America,
Central America, South America, Asia, Africa, Australia, Pacific Islands. Acroporium occurs predominantly on logs,
occasionally epiphytic at tree trunk bases, particularly in forested sites. SELECTED
REFERENCES: Crum, H.A. and L.E. Anderson. 1960. A bryological contribution
from 1. Acroporium smallii (Williams) H. A. Crum & L. E.
Anderson, Bryologist 63: 42. 1960 Sematophyllum smallii Williams, Bryologist 23: 76. 1920 Plants small and delicate, in pale green to
golden glossy creeping mats. Stems
ca. 1 cm, leafy branches 0.4--0.6 x 0.7--1 mm. Leaves
0.5--0.7 mm, median leaf cells narrowly rhomboid to linear, alar cells
without apparent supra-alar cells. Sexual condition autoicous. Seta
4--7 mm, smooth. Capsule urn
0.4--0.6 mm, erect to inclined, annulus absent. Spores
spherical, slightly roughened, 13--14 \um. Rotten logs,
tree bark or charred wood, in moist live-oak hammocks. Confined to Dade Co., Distinctive
gametophytic traits of Acroporium
smallii include the long-ovate leaves with erect margins, linear medial
cells, and alar cells much inflated and sharply differentiated from more
distal cells. |
