|
BFNA
Title: Ceratolejeunea |
|
9.
CERATOLEJEUNEA Jack & Stephani, Hedwigia 31: 16. 1892 * [Greek keras, horn, and Lejeunea, name
of a related genus]. Barbara M. Thiers Plants 1--1.5 mm wide,
tightly appressed to substrate, brown to reddish brown, microphyllous
branches occasionally present. Stems with 7 epidermal cells surrounding
10--20 cortical cells. Lateral leaves widely spreading when
dry, plane to convex when moist; lobe ovate to ovate-falcate, apex bluntly
rounded; trigones small to large, triangular to cordate,
intermediate thickenings sometimes present, cell walls with a brown middle lamella; oil bodies 3--5 per
cell, oblong, small to moderate in size, segmented to botryoidal,
ocelli usually present, 1--5 per leaf, basal or
grouped in leaf midportion. Lobule
fully formed or reduced, usually ovoid, convex proximally, plane
distally, free margin inrolled for about 0.75--0.9 lobule length, with 1
single-celled, often falcate tooth, hyaline papilla at its proximal base;
lobules at stem bases sometimes utriculate (i.e.,
as large as leaf lobe, strongly inflated with free margin strongly inrolled for entire length). Underleaves
distant to contiguous, ovate to orbiculate, 1.5--2
times stem length, 2-fid; lobes erect, triangular; lateral margins entire,
basal marginal cells not distinctly larger than adjacent cells, rhizoid disc
not differentiated. Specialized asexual reproduction rare
(caducous leaf lobes and leaf margin regeneration
in C. laetefusca). Sexual
condition autoicous or dioicous. Androecia usually on short branches,
bracteoles at base. Gynoecial innovations 1--2, leaf
sequence pycnolejeuneoid, bracts somewhat larger
than lateral leaves, keel rounded to acutely folded, not winged; perianth
with 4 keels forming shoulder-like crests or terete horns that extend beyond apex
of perianth. Species
19 (3 in the flora): pantropical, with greatest
diversity in neotropics. Ceratolejeunea is generally easily
distinguished from other Lejeuneaceae subfamily Lejeuneoideae by the dark color of the plants, presence
of ocelli, utriculate
lobules, and the horned perianths, although not all species possess all of
these features. G. Dauphin (2003) recognized
two subgenera (Ceratolejeunea
and Caducifolia). All of the North American species belong to
subgenus Caducifolia. SELECTED
REFERENCES Dauphin, G. 2003.
Ceratolejeunea. Flora Neotropica
Monographs 90: 1--86. Fulford, M. 1944. Studies on American Hepaticae--VI.
Ceratolejeunea. Brittonia 5:
368--403. Schuster, R. M. 1980.
Ceratolejeunea. In: R. M. Schuster. 1966--1993.
Hepaticae and Anthocerotae of North
America. New York. Vol. 4, pp.
909--929. 1. Ocelli forming a line
extending from base to leaf midportion
...
3. Ceratolejeunea ceratantha 1. Ocelli
basal or absent. 2. Perianth keels forming crests (rather than distinct
horns); plants usually dioicous; leaf
margins entire; utriculate lobules absent; asexual
reproduction by regeneration from leaf margin or by dehiscent leaf lobes
sometimes present
..2. Ceratolejeunea laetefusca 2. Perianth keels forming terete horns; plants autoicous or dioicous; leaf
margins entire or irregularly dentate near leaf apex; utriculate
lobules often present at branch bases, asexual reproduction absent
..
1.
Ceratolejeunea cubensis 1. Ceratolejeunea cubensis (Montagne)
Schiffner in A. Engler & K. Prantl, Nat. Pflanzenfam. 1(3): 125. 1893
Lejeunea cubensis Montagne
in Sagra, Hist. Phys. Cuba (Bot. - Pl. Cell.), 481.
1842 Plants yellowish or reddish brown
when dry. Lateral leaf lobe ovate, sometimes somewhat falcate, margin, entire
or weakly toothed near apex, apex rounded to broadly or sharply acute,
sometimes incurved when dry; ocelli, 0--5 in cluster (i.e., ocelli adjacent
along long axis) at leaf base. Utriculate lobules occasionally
present at branch bases. Sexual condition autoicous or
dioicous. Perianth
obovoid, 4 keels forming smooth triangular horns with tapering tips, dorsal
keel absent. Bark of living trees, on decorticated wood, or creeping
over living filmy ferns and decorticated wood in humid, restricted to densely
vegetated "islands" of subtropical forest (i.e., hammocks) in South
Florida; 0--10 m; Fla.; Mexico; West Indies; Bermuda; Central America; South
America. Ceratolejeunea cubensis can be distinguished from
C. laetefusca
by the usual presence of at least a few weak teeth on the margin, and the
perianth keels form distinct horns rather than
crests. Also, C. cubensis is usually autoicous, and utriculate lobules are sometimes present at branch bases.
Dehiscent leaves are lacking in C. cubensis. 2. Ceratolejeunea laetefusca (Austin) R. M. Schuster,
J. Elisha Mitchell Sci. Soc. 72: 306.
1956 Lejeunea laetefusca Austin, Bot. Gaz. (Hanover).
1: 36. 1876 Plants light to olive brown when
dry. Lateral leaf lobe ovate, sometimes slightly falcate, margin entire,
irregular or crenulate, apex rounded rarely toothed,
plane when dry; ocelli consistently present, 1--5 in
a cluster (i.e., ocelli adjacent along long axis) at
leaf base. Utriculate lobules absent. Specialized asexual reproduction sometimes
present, by dehiscent leaves or by plant regeneration from leaf margin cells.
Sexual
condition dioicous, rarely autoicous.
Perianth ellipsoid, 4 keels forming smooth
compressed, sharply-angled crests (horns absent), dorsal keel sometimes
present as weak fold. Bark
of living trees; evergreen forests in moist subtropical portions of se
Coastal Plain; low elevations; Fla., Ga., La., Miss., S.C.; West Indies;
Central America; South America. Ceratolejeunea laetefusca is the most common
species of the genus in North America.
It is rarely found with mature perianths, and sterile plants might be
mistaken for a species of Cheilolejeunea.
Careful observation of the hyaline papilla should resolve any
confusion, however, because the papilla is proximal to the marginal tooth in Ceratolejeunea,
but distal in Cheilolejeunea.
The brown pigmentation, usually present in C. laetefusca will also usually
distinguish it from other Lejeuneaceae with
undivided underleaves. Although C.
guianensis has been reported from the U.S. by M.
Fulford (1945), and rather tentatively by G. Dauphin
(2003), no specimens observed for this study could be referred to C. guianensis. G. Dauphin (2003) differentiated C. guianensis
from C. laetefusca
by are the presence of flagelliform branches and leaves incurved when dry,
but also stated that these differences are not sufficient to separate the
taxa. 3.
Ceratolejeunea ceratantha (Nees & Mont.)
Schiffner, Bot. Jarhb.23: 582. 1897 Lejeunea ceratantha Nees & Montagne, Ann. Sci. Nat. ser. 2. Bot. 14: 335. 1840 Plants reddish brown when
dry. Lateral leaf lobe asymmetrically ovate, somewhat falcate, margin entire
to crenate or toothed on antical margin and leaf apex,
apex rounded to sharply acute, plane; ocelli
usually present, 2--5 in a line (i.e., adjacent ocelli
joined along short axis) extending from leaf base into leaf midportion. Utriculate lobules occasionally present at
branch bases. Sexual condition autoicous.
Perianth obovoid, keels forming 4 triangular
horns with tapered or inflated tips, surface crenuate,
dorsal keel absent. Bark
at base of living trees; humid, densely vegetated areas of subtropical forest
(i.e., hammocks); low elevations; Fla.; West Indies; Central America. Ceratolejeunea ceratantha is known from only two
collections in Florida, both of which were treated by R. M. Schuster (1980)
as C. rubiginosa
Steph. G. Dauphin (2003) identified one of these as C. ceratantha,
which he differentiates from C. rubiginosa on the basis of ocelli
in a broken line (i.e., ocelli separated by non-ocellate cells) in
C. ceratantha
rather than in an unbroken line in C. rubiginosa, and a leaf margin dentate only at the
apex (as opposed to along the entire antical apex
in C. rubiginosa). The Florida collections are scanty and depauperate, but exhibit an
entire to weakly dentate leaf margin and the ocelli
are single or absent in some leaves, or may form a broken line in the leaf
midportion, characters that suggest C. ceratantha. OTHER REFERENCES Schuster, R. M. 1963.
An annotated synopsis of the genera and subgenera of Lejeuneaceae. Nova
Hedwigia Beih. 9: 1--203. Schuster, R. M. 1984.
Evolution, Phylogeny and Classification of the Hepaticae. In: R. M. Schuster, ed. 1984.
New Manual of Bryology. Vol. 2,
pp. 892--1070. Nichinan,
Japan.
|
|
|