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BFNA
Title: Amblystegiaceae |
XX. Amblystegiaceae G.
Roth
Plants small, medium-sized, or large; green, yellowish, or
brownish. Stem distichously
branched, sometimes almost unbranched; cortex of small and incrassate cells;
hyalodermis present or not; pseudoparaphyllia mostly foliose, the outer
occasionally filamentose; paraphyllia absent or present; rhizoids red-brown,
smooth or warty-papillose, slightly or strongly branched; rhizoids or rhizoid
initials on stem at or just below leaf insertions or from lower back of costa,
occasionally from leaf lamina near leaf apex (Conardia); axillary hairs mostly well developed. Stem leaves straight or falcate
(gradually curved) or squarrose, plicate or smooth; costa single and mostly
long, or double and usually short; median lamina cells linear or short-linear,
rarely rectangular or hexagonal, 1-stratose or sometimes partially 2- or
multistratose, smooth or rarely prorate or papillose; alar cells differentiated
or not, sometimes inflated. Inner
perichaetial leaves straight and erect, lanceolate or ovate or oblong or
slightly obovate, plicate or rarely smooth; costa usually well developed,
single or double; vaginula with paraphyses. Seta long or rarely short, smooth. Capsule cylindric or short-cylindric, curved and horizontal to
straight and erect, stomata long-pored; annulus separating or not; operculum conic
or rarely rostrate or short-rostrate. Peristome
perfect or specialized; perfect exostomes yellow-brown or brownish,
cross-striolate or sometimes reticulate on outer surface below, papillose
distally, with dentate or slightly dentate margin and an exostome border ±
widened at zone of transition in outer peristomial layer pattern; specialized
exostome teeth variously narrow or short, sometimes with outer surface basally papillose;
perfect endostomes with high basal membrane, segments long and not or
narrow-perforate, cilia nodose or sometimes appendiculate; specialized
endostomes with basal membrane ± reduced or sometimes absent, cilia short to
absent, segments narrower and sometimes shorter than in perfect endostomes. Calyptra cucullate, smooth.
Genera 20--30, species 100--150 (18
genera, XXX species in the flora): temperate to sub-polar regions worldwide,
tropical mountains.
The
Amblystegiaceae as here circumscribed, excluding the Calliergonaceae, include
several genera or species groups that may not belong to or are even unlikely to
belong to this family in a strict sense. These include Calliergonella,
Campylophyllum, Conardia, Donrichardsia, most of Hygrohypnum, Platylomella, Sanionia, and Tomentypnum.
At the moment, however, knowledge of the relationships of these taxa is still
limited, and they are therefore included with the Amblystegiaceae. The genus Amblystegium is here understood in a
wide sense, including Hygroamblystegium,
but excluding Serpoleskea (here
treated in Platydictya).
Members of the
Amblystegiaceae are sometimes confused with those of other pleurocarpous
families, such as the Brachytheciaceae and Plagiotheciaceae. Most members of
the Brachytheciaceae and Plagiotheciaceae differ from those of the
Amblystegiaceae in their non-plicate and often recurved rather than plicate and
erect inner perichaetial leaves (in species with horizontal capsules). In the
Brachytheciaceae horizontal capsules are swollen rather than cylindric, the
stomata round-pored rather than long-pored, and the exostome base is mostly red
or brown-red rather than yellow-brown. The exostome teeth borders are gradually
narrowed upwards rather than suddenly widened where the outside pattern of the
teeth changes from cross-striolate to papillose, the endostome segments are
widely rather than narrowly perforate, and the spores mature in the winter
rather than the summer half of the year in temperate areas. Plagiotheciaceae
members have pale whitish yellow exostomes and, in addition, differ from the
Amblystegiaceae in several diagnostic gametophyte features, including rhizoid
position and ornamentation, and branching mode (see Platydictya treatment). On the other hand, the morphological
differences between members of the Amblystegiaceae s. str. and those of other
families, such as the Hypnaceae and Thuidiaceae, or the sometimes segregated or
recognized Campyliaceae, Cratoneuraceae, Donrichardsiaceae, and Helodiaceae,
are more diffuse. Differences between the Amblystegiaceae and the
Calliergonaceae are discussed under the latter.
SELECTED
REFERENCES Hedenäs, L. 2003.
Amblystegiaceae (Musci). Flora Neotropica, Monograph 89: 1--107. Hedenäs, L. and A. Vanderpoorten. 2007. The
Amblystegiaceae and Calliergonaceae. In: A. E. Newton and R. Tangney, eds.
Pleurocarpous Mosses: Systematics and Evolution. The Systematics Association
Special Volume Series 71, pp. 163--176. Vanderpoorten, A., B. Goffinet, L. Hedenäs,
C. Cox, and A. J. Shaw. 2003. A taxonomic reassessment of the Vittiaceae
(Hypnales, Bryopsida): evidence from phylogenetic analyses of combined
chloroplast and nuclear sequence data. Plant Syst. Evol. 241: 1--12.
Vanderpoorten, A., L. Hedenäs, C. Cox, and A. J. Shaw. 2002. Phylogeny and
morphological evolution of the Amblystegiaceae (Bryopsida). Molec. Phylog.
Evol. 23: 1--21. Vanderpoorten, A., L. Hedenäs, C. Cox, and A. J. Shaw. 2002. Circumscription,
classification, and taxonomy of Amblystegiaceae (Bryopsida) inferred from
nuclear and chloroplast DNA sequence data and morphology. Taxon 51: 115--122.
1. Leaves with wide 2--5-stratose border
or intramarginal band of rectangular or linear cells, sometimes 1-stratose near
leaf base and leaf apex.
2. Leaves
with 2--4-stratose marginal border; margin denticulate; plants creeping,
irregularly to subpinnately branched..................................................................................................... 18.
Platylomella, p. xx
2. Leaves
with 2--5-stratose intramarginal band; margin dentate; plants dendroid.
........................................................................................................... 17.
Limbella, p. xx
1. Leaves without clearly differentiated
multistratose border or intramarginal band.
3. Stem with at
least a partial hyalodermis.
4. Stem
leaves plicate or strongly so; costa single and long............... 12. Sanionia,
p. xx
4. Stem leaves
smooth; costa single and long, or short and double.
5. Species
in or close to running water or lake shores; costa in most leaves either single
and long, double or branched and ending in mid-leaf, or short and double; when
short and double median leaf lamina cells 27.5--66 \um ............................................................. 3.
Hygrohypnum (in part), p. xx
5. Species
in various wet and humid habitats; costa short and double; median leaf lamina
cells 42--115(--145) \um.............................................................................. 14.
Calliergonella, p. xx
3. Stem without
hyalodermis.
6. Alar cells of
stem leaves not differentiated from other basal cells; costa single.
7. Golden
yellow plants with strongly plicate leaves; leaf apex longly acuminate; often
with numerous, strongly branched rhizoids from proximal abaxial surface of
costa. 13. Tomentypnum, p. xx
7. Green or
brownish plants with smooth leaves; rhizoids sparsely branched, never from abaxial
surface of costa.
......................................................... 11.
Hygroamblystegium (in part), p. xx
6. Alar cells of
stem leaves more or less differentiated, small or inflated, sharply or
diffusely delimited from surrounding cells; costa single or double.
8. Stem leaves at
most 1 mm.
9. Rhizoids
or rhizoid initials present on abaxial surface of costa or on lamina near leaf
apex; rhizoids warty-papillose and often strongly branched, then forming
tomentum. 15. Conardia, p. xx
9. Rhizoids or
rhizoid initials only on stem or at abaxial costa insertion, never on leaves; rhizoids
smooth or rarely granular-papillose, slightly to strongly branched, rarely
forming tomentum.
10. Stem leaves
from erect to spreading base recurved or squarrose, at least along some shoot
portions; acumen when differentiated distinctly furrowed.
11. Stem leaf costa
short and double, often ending in a spine on back of leaf; scattered distal lamina
cells usually distally prorate on dorsal side, at least in some branch leaves;
seta relatively short, 8--22 mm.
12. Most or
many leaves with clearly differentiated acumen; leaf apex acuminate or narrowly
so......................................................... 16.
Campylophyllum, p. xx
12. Leaf
acumen not differentiated; leaf apex acute or blunt.
................................................. 3.
Hygrohypnum (in part), p. xx
11. Stem leaf costa
long and single, or sometimes shorter and double in some (rarely all) leaves,
not ending in a spine on back of leaf; distal lamina cells smooth; seta often
long, 12--45 mm.
13. Largest
cells in proximal half of alar group in stem leaves 18--25 \um wide;
paraphyllia often present, narrow-lanceolate to ovate-lanceolate; autoicous;
endostome cilia nodose.
..................................................... 11.
Pseudocampylium , p. xx
13. Largest
cells in proximal half of alar group in stem leaves 10.5--19(--21) \um wide;
paraphyllia absent; dioicous; endostome cilia nodose or partially
appendiculate. 6. Campyliadelphus, p. xx
10. Stem leaves
variously straight or falcate, but not recurved to squarrose; acumen plane or
almost so.
14. Plants
submerged in brooks and rivers, sometimes on irrigated rocks; leaves almost
orbicular, broadly ovate, or ovate; in the latter case stem leaves either with
broadly rounded apex or alar groups well differentiated............................. 3.
Hygrohypnum, p. xx
14. Plants
terrestrial (sometimes on shores). Leaves varying around ovate; leaf apex
acuminate, if blunt with alar cells weakly differentiated from other basal
cells.
15. Costa
double and short.............................. 4. Platydictya, p. xx
15. Costa single.
16. Capsule
straight and erect; operculum short-rostrate; exostome teeth short, papillose
throughout; endostome lacking basal membrane and cilia; plants usually growing as epiphytes on trees, sometimes on rotten
wood. 5. Anacamptodon, p. xx
16. Capsule
curved and horizontal; operculum conic; exostome well developed, teeth
cross-striolate basally; endostome with basal membrane, cilia mostly well
developed; plants of various habitats................................ 11.
Amblystegium, p. xx
8. Stem leaves
longer than 1 mm.
17. Stem leaves
from erect to spreading base recurved or squarrose, at least along some shoot
portions; acumen distinctly furrowed.
18. Stem
leaves to 1.7 mm; alar cells slightly inflated, widest alar cells 10.5--17.5(--21) \um wide.................................................................... 6.
Campyliadelphus, p. xx
18. Stem leaves at
least 1.6 mm; alar cells strongly inflated, widest alar cells 17--31.5 \um wide.
19. Stem leaf costa double and short; alar cells forming an ovate or
rectangular group along basal margin of leaf, extending from leaf margin 28--33%
of distance to leaf middle at insertion; dioicous.
....................................................................... 7.
Campylium, p. xx
19. Stem leaf costa single and long, or often double and short in at
least some leaves; alar cells forming a transverse-triangular group, extending
from leaf margin 67--100% of distance to leaf middle at insertion; autoicous......... 9. Drepanocladus (in part),
p. xx
17. Stem leaves
variously straight or falcate, but not recurved to squarrose; acumen plane or
furrowed.
20. Paraphyllia present
on stem, occasionally rare and visible only in youngest shoot portion; rhizoids
stem-borne, often forming tomentum.
21. Stem
leaves plicate; at least some median lamina cells usually prorate or papillose
abaxially; paraphyllia linear or lanceolate-linear.
....................................................................... 2.
Palustriella, p. xx
21. Stem
leaves smooth; median lamina cells smooth; paraphyllia ± lanceolate.
22. Monoicious; alar cells green to brownish-orange, not or slightly
inflated; stem leaves lanceolate, entire to finely denticulate throughout. XX. Hygroamblystegium
(in part), p. xx
22. Dioicious; alar cells mostly inflated and hyaline; stem leaves
triangular, broadened at base, serrate in the proximal 1/3
................................................................ 1.
Cratoneuron, p. xx
20.
Paraphyllia absent; rhizoids rarely forming tomentum; when much branched
usually inserted on proximal abaxial surface of costa.
23. Stem leaf costa
double or forked, short or ending up to mid-leaf or slightly above.
24. Alar
cells quadrate to long-rectangular, more or less strongly incrassate, inflated
or slightly inflated; alar group indistinctly delimited, large,
transverse-triangular; axillary hairs early yellow or brownish.......................... 10. Pseudocalliergon, p. xx
24. Alar
cells and alar group different; axillary hairs hyaline when young. 3. Hygrohypnum
(in part), p. xx
23. Stem leaf costa
single and long.
25. Alar cells of
stem leaves distinctly delimited from surrounding cells.
26. Alar
cells not or slightly inflated; frequently in streams or on wet rocks. 3. Hygrohypnum
(in part), p. xx
26. Alar
cells strongly inflatedl; usually in other wet habitats than running water. 9. Drepanocladus
(in part), p. xx
25. Alar cells of
stem leaves gradually delimited from surrounding cells.
27. Rhizoids
or rhizoid initials present abaxially on costa or on lamina near leaf apex;
rhizoids warty-papillose and strongly branched, often forming tomentum. 15. Conardia,
p. xx
27. Rhizoids or
rhizoid initials only on stem or abaxially on costal insertion, never on
leaves; rhizoids smooth, slightly to strongly branched, rarely forming
tomentum.
28. Alar cells
of stem leaves mostly incrassate to strongly so, rarely thin-walled in mature
leaves; axillary hairs well developed, abundant, with early yellowish or
brownish distal cells.
.............................................. 10.
Pseudocalliergon, p. xx
28. Alar cells of
stem leaves thin-walled or slightly incrassate in mature leaves; axillary hairs
well developed and abundant or small, delicate and sparse, with young distal cells
hyaline.
29. Leaf
apex rounded or blunt; costa ending 1/2--3/4 way up leaf; plants submerged in
brooks and rivers, sometimes on irrigated rocks. 3. Hygrohypnum (in
part), p. xx
29. Leaf
apex acuminate; if blunt or obtuse then costa ending in or just before apex; plants
of various habitats, sometimes submerged.
30. Stem
leaf costa ending 60--75% of way up leaf,
(45--) 52.5--114 \um wide near base; median lamina cells 42--117 \um. 8. Leptodictyum, p.
xx
30. Stem
leaf costa ending in distal acumen to percurrent, or ending somewhat farther
down in acumen (in latter case, 29.5--58(--77.5) \um wide near base); median lamina cells (9--)13--65(--67) \um.
................... 11. Hygroamblystegium (in part), p. xx