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BFNA Title: Leptodontaceae |
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Lloyd
R. Stark Plants epiphytic, small to medium in size, light
to yellow-green, with creeping primary stems bearing arcuate
to erect branches. Stems irregularly pinnately branched, the branches
incurved or rigid when dry and produced in clusters of 1--5 on either side of
a vegetative growth interval; paraphyllia present or absent; pseudoparaphyllia subfoliose to
nearly filamentous, entire; axillary hairs 6--8 per axil,
of 1--2 short proximal cells with brownish walls and 2--4 elongate hyaline distal
cells. Branches short to elongate, simple to much-branched. Leaves
spirally inserted, loosely appressed to imbricate, erect spreading to nearly squarrose when moist, rapidly spreading when moistened,
mostly ovate-lanceolate, margins entire or serrate distally, apex acute to
shortly acuminate; costa single and ending before leaf apex or short and
double; medial cells isodiametric to linear,
smooth; alar cells quadrate to transversely
elongate. Sexual condition autoicous or dioicous. Perigonia
gemmiform, lateral. Perichaetia
larger, lateral, with elongating paraphyses and
inner perichaetial leaves following fertilization. Specialized asexual reproduction absent. Seta single, 1--4
mm in length. Capsule immersed to emergent, erect, cylindrical, symmetric,
stomates absent or basal and sunken; annulus absent; operculum
conic-rostrate; peristome mostly double, pale; exostome of 16 teeth;
endostome rudimentary or absent to well developed, cilia absent. Calyptra
cucullate, hairy. Spores spheric, minutely
papillose. Genera 5--6, species ca.
20--30 (3 genera, 4 species in the flora): worldwide, primarily temperate
regions. The family Leptodontaceae
is defined by the combination of epiphytic habit, branching pattern of clusters
of branches alternate with unbranched intervals
bearing inflorescences, “double” sporophytic phenological cycle in which two cohorts of sporophytes mature simultaneously with embryos overwintering, subfoliose pseudoparaphyllia, cucullate calyptrae,
sheathing postfertilization perichaetial leaves, central
strands lacking in shoots, shortened setae, no annuli, and a hydrocastique exostome that flexes open when wet and
flexes inward when dry, thus serving to disperse spores during wet periods. The Leptodontaceae
as treated here comprise only Forsstroemia, Leptodon, and Alsia. Recently described or
relocated genera in the family include Taiwanobryum, Cryptoleptodon,
and Caduciella
(J. Enroth 1991, 1992, 1993). Molecular evidence indicates that this
small family may not be monophyletic, and is better viewed within the larger
context of the family Neckeraceae (e.g., S. Maeda
et al. 2000; M. S. Ignatov et al. 2007). SELECTED REFERENCES Enroth, J.
1992. Corrections to Cryptoleptodon,
Forrstroemia
and Leptodon
(Leptodontaceae, Musci). Journal of the Hattori
Botanical Laboratory 71: 75--82. Maeda, S., K. Kosuge,
D. Gonzalez, E. De Luna, and H. Akiyama. 2000. Molecular phylogeny of the
suborder Leucodontineae (Musci; Leucodontales)
inferred from rbcL
sequence data. Journal of Plant Research 113: 29--38. Stark, L. R. 1987. A
taxonomic monograph of Forsstroemia
Lindb. (Bryopsida: Leptodontaceae). Journal of the Hattori Botanical
Laboratory 63: 133--218. Ignatov, M. S., A. A. Gardiner, V. K. Bobrova, I. A. Milyutina, S. Huttunen, and A. V. Troitsky.
2007. On the relationships of mosses of the order Hypnales,
with special reference to taxa traditionally classified in the Leskeaceae. In:
A. E. Newton and R. S. Tangney, eds. 2007. Pleurocarpous
mosses, systematics and evolution. 1. Paraphyllia absent . . . .
1. Forsstroemia, p. XX. 1. Paraphyllia present. 2. Secondary stems flagelliform,
[calyptra hairy, endostome rudimentary,] rare ( 2. Secondary
stems not flagelliform, calyptra
smooth, endostome well developed, common in |