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BFNA Title: Trichocolea |
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XX. TRICHOCOLEACEAE Nakai Patricia M. Eckel Plants forming thick mats ; branches
usually replacing ventral half of a lateral leaf; without [with] tapered,
flagelliform distally microphyllous lateral branches . Leaves
alternate, succubous [weakly incubus], plane, deeply lobed, with lobes
divided into a mass of branched uniseriate cilia; underleaves large, deeply
lobed, with lobes divided into a mass of 1-seriate cilia. Stems often covered
with filamentous paraphyllia. Rhizoids absent or rarely present as
hyaline tufts restricted to underleaf bases. Specialized asexual
reproduction absent. Gynoecium terminal or on an ordinary leafy
branch, often subtended by 2 subfloral branches. Perianth absent
[present and rudimentary]. Perigynium erect, clavate, an epicoelocaule [cryptocoelocaule,
shoot calyptra], bearing old archegonia [laterally or] near its tip. Genera 3 (1 in the flora):
eastern North America, Mexico, West Indies, Central
America, South America, Eurasia, Africa (Tunisia), Pacific Islands,
Australia. Trichocoleaceae occur in areas rich with bryophytes, and include
terrestrial species, with habitats including trunks and branches of trees,
and on soil in shaded, moist evergreen (Nothofagus)
or deciduous forests and tropical or subtropical lowland to montane rainforests.
The family is characterized by their highly ciliate leaves and by having
their sporophytes associated with erect perigynia ,
i.e., structures that are derived from the stem tissue just below the
fertilized archegonium that replace either a part
or all of the calyptra, with or without an associated perianth. Perigynial structures in the family include the epicoelocaule,
in which the sporophyte is completely enclosed by stem tissue, and both perianth
and calyptra are lacking.. The family also displays
two structures with perianths: the cryptocoelocaule,
and the shoot calyptra (with perigynial tissue at
its base). The epicoelocaule alone occurs in two of
the three genera in the family, and is the structure characteristic of Trichocolea. In
Trichocolea the epicoelocaule
surface is hispid proximally with reduced fragments of scattered bractlets and paraphyllia throughout, unfertilized or
aborted archegonia at the apex, and bracts and bracteoles at the base. Other
characters of the family include elongate, thin-walled leaf cells lacking
corner-thickenings. The three genera (Eotrichocolea,
Leimomitra and Trichocolea)
are supported as comprising a monophyletic family in the molecular
phylogenetic analysis of D. Glenny et al. (2009). SELECTED REFERENCES Glenny, D., J. J. Engel and X. He-Nygrén. 2009. The systematic identity of Chiloscyphus trichocoleoides,
a new liverwort species from New Zealand, uncovered by morphological and
molecular evidence. J. Bryol. 31: 93--105.
Katagiri, T.and H.
Deguchi. 2012. Taxonomic studies of the Trichocoleaceae in Southeast Asia. I. The genus Leiomitra Lindb.
Bryologist 115: 474--491. Katagiri, T., M. Suleiman and H. Deguchi.
2012. Taxonomic studies of the Trichocoleaceae in
Southeast Asia II. A new species of Eotrichocolea
from Malaysia. Bryologist 115: 518--522. Katagiri,
T., A. Sadamitsu, H. Miyauchi,
H. Tsubota and H. Deguchi.
2013. Taxonomic studies of the Trichocoleaceae in
Southeast Asia. III. The genus Trichocolea
Dumort. Hattoria 4: 1--42. 1. TRICHOCOLEA Dumortier, Commenat.
Bot., 113. 1822, orth. cons. “Thricholea” * [Greek thrix, ‘hair,’ and koleos,
‘sheath,’ alluding to the hairy, fleshy, sheath-like stem perigynium
surrounding the sporophyte during its development.] Plants in tufts, loose to dense mats or interwoven among other
bryophytes, prostrate to ascending, whitish to yellowish green, paler when
dry, secondary pigmentation lacking [reddish, orange to brownish], growth
monopodial. Stem with lateral terminal branches of the Frullania-type, i.e. bearing dorsal
half-leaves inserted just below the branch and having half the number of
lobes of the regular leaf, i.e. 2-fid; branches regularly [irregularly]
[1--]2--3-pinnate; stem cross section
more than 12--16[--35] cells in diameter, nearly homogeneous,epidermal
cells [strongly to] subdistinct, in 1--2[--7]
layers, somewhat smaller with thicker walls than the larger, very thin-walled
cortical cells; cuticle [strongly papillate- to] rather weakly striolate-
verruculose; paraphyllia abundant
[absent ], uniseriate, often branched, on dorsal surface of stems and
branches. Rhizoids, when present, colorless, distal ends digitate. Lateral
leaves succubous, subobliquely to
subtransversely inserted, distant, contiguous to imbricate on the branches,
semi-amplexicaulous, asymmetric, subconcave, the smaller ventral part of leaf
subtransversely inserted on the ventral side of the stem; undivided leaf
lamina (disc) (1--)3--4(--18) cells high, divided unequally into
(3--)4--5(--9) triangular lobes, the lamina without [with] superficial cilia,
irregularly bifurcately branched, narrowed into masses of long 1-seriate or
2-furcate cilia, margins densely laciniate-ciliate, cilia linear-subulate,
(2--)4--6 cells long, septa not dilated [dilated], not fragile [fragile],
distal ends not thickened [thickened, cap-like], leaf cells mostly
rectangular, equally thin-walled, lacking trigones, with the cuticle weakly
verruculose-striate [strongly papillate]; oil bodies small, distinct, without
[with] an ocellus. Underleaves large, similar to lateral leaves but
smaller, as wide as the stem or wider, insertion transverse, symmetrical,
twice 2-fid, appearing deeply 4-lobed nearly to the base, the lobes as
densely laciniate-ciliate as the lateral leaves. Specialized asexual
reproduction unknown, cilia intact [fragile and fragmenting in one exotic
species]. Sexual condition dioicous. Antheridial plants,
not distinct from vegetative, and smaller than archegoniate plants. Androecia
terminal on primary branches, bracts similar to the leaves but smaller,
in (9--)12--15(--16) pairs, closely imbricate,
weakly concave at the base, each bract subtending (1--)2 large, globose
antheridia with 2-seriate; bracteoles similar to the underleaves, lacking
antheridia. Gynoecia terminal on primary or elongate lateral branches,
pseudolateral due to the development of (1--)2 subfloral branches; with bracts and bracteoles in 3
imbricate cycles; bracts and bracteoles larger than but similar to the leaves
and underleaves except more densely ciliate and more shallowly and frequently
lobed, surrounding the otherwise naked archegonia which are immersed in a
dense mass of paraphyllia. Perianth and calyptra absent. Stem perigynium
erect, fleshy, clavate, an epicoelocaule,, bracts and bracteoles inserted below epicoelocaule base, elongating surface bearing dense
proximal rudimentary bractlets, receptacular
paraphyllia, and distally unfertilized or aborted archegonia. Sporophytes
massive, foot obconoidal, seta
long, thick; capsule narrow, ellipsoidal, regularly dehiscing into 4 valves;
capsule walls in 4--7 layers, outer walls without or rarely with linear to semiannular thickenings; inner layers of smaller cells
with nodular semiannular and annular thickenings. Elaters
free, 2(--3)-spiraled,0.1--0.2 mm, reddish
brown. Spores orbicular-ovoid, reddish brown to brown, 10--14(--18)
/um, smooth or minutely granulate. Species 20 (1 in the flora): e North America, s Mexico,
West Indies, Central America, South America, Eurasia, Africa (Tunisia),
Pacific Islands, Australia. Trichocolea is separated from other genera in the family “by the
regularly 1--3-pinnate habit; the obliquely to subtransversely inserted
leaves, the succubous leaf insertion, the stem cortex of 1--5 layers of leptodermous cells, the epicoelocaule
with perianth absent and ellipsoidal capsule dehiscing into four regular
valves” (Katagiri et al. 2013). Both the similar
ciliate-leaved genera Ptilidium and Blepharostoma frequently develop fruiting
structures, and have well-developed perianths, not a fleshy, paraphyllose stem-derived perigynium as in the
rarely-fruiting Trichocolea. Ptilidium has incubous (not succubous) leaves with
smooth, thick-walled leaf-cells and bulging trichomes,
rhizoids evident on the stem, and lacks paraphyllia. Blepharostoma
trichophyllum is autoicous (or paroicous) has
leaf lobes completely 1-seriate-ciliate throughout, the leaf cells
thick-walled and with 1-seriate chains of gemmae at the leaf apices. While Trichocolea is conspicuously regularly
2--3-pinnate in branching, Ptilidium is
irregularly 1--2-pinnate, and Blepharostoma
is only sparingly branched. SELECTED REFERENCES Hatcher, R. 1957. The genus Trichocolea in North, Central, and South America
(Hepaticae). Lloydia 20: 139-185. Hatcher, R. 1959. The structure of the
female inflorescence and its taxonomic value in the genus Trichocolea.
(Hepaticae). Lloydia 22: 208-214. Katagiri, T., A. Sadamitsu, H. Miyauchi, H. Tsubota and H. Deguchi. 2013. Taxonomic studies of the Trichocoleaceae in Southeast Asia. III. The genus Trichocolea Dumort. Hattoria 4: 1--42. R. M. Schuster. 1966. Hepaticae and
Anthocerotae of North America East of the Hundredth Meridian, Vol. 1.
Colombia Univ. Press, New York. 802 pp.. 1. Trichocolea tomentella (Ehrh.) Dumort.,
Syll. Jungerm. Europ., 67. 1831 Jungermannia tomentella Ehrh., Hannover. Mag. 21: 277.
1783; Trichocolea biddlecomiae
Austin Plants robust, constantly light grayish to yellowish green above a
brownish base, 5--13 (--16) cm long, the entire plant 1--2.5(--3) cm wide;
branches growing loosely, procumbent, suberect or ascending, in loose or
dense hummock-like mats. Stem diameter ( 0.4--)0.6--
0.75(--1.5 mm) wide, regularly 2--3-pinnate. Lateral leaves to 1 mm x
2 mm, unevenly divided 0.5--0.9 of their lengths into 4--5(--8) very narrow
lobes, undivided lamina (disc) to 3 cells high, lacking surficial cilia, the
margin densely ciliate; cilia of leaves not fragile, linear, (3--)4-6(--7) cells long, uniformly thin-walled, terminal
cells straight, only somewhat longer than penultimate cells, septa
thin-walled, flat. Oil bodies
small, (3--)6--8(--10) per cell, faintly granular or
with spherules. Neutral to calcareous substrates, absent from acid habitats
such as peat bogs, terrestrial on constantly moist to wet (not inundated),
usually humus-rich soil, in (cedar) swamps in depressions, on rotted stumps
and trunks, in peaty hummocks, on the slopes and banks of streamlets, on
diffusely shaded rocks in humid to wet deciduous woods; less common in
ravines on vertical rocks, ledges and banks in dripping wet habitats, best
developed into dense, deep mats in swamps; absent from the trunks of trees;
0--1200(--3000) m; Miquelon; Nfld., N.S., Ont., Que.; Ark., Conn., D.C., Del., Fla., Ga., Ill.,
Ind., Iowa, Ky., Maine, Mich., Md., Mass., Minn., Mo., N.H., N.J., N.Y.,
N.C., Ohio, Pa., R.I., S.C., Tenn., Vt., Va., W.Va., Wis; Europe; Asia;
Africa (Tunisia); Atlantic Islands (Azores); Pacific Islands. Antheridate plants of Trichocolea tomentella are reported to be very rare, or are
inconspicuous. Plants with sporophytes are very rare perhaps due to sexually
disjunct populations; female plants are somewhat more frequent, the gynoecium
inconspicuous, hidden in dense paraphyllia but are also often overlooked. Trichocolea tomentella
is distinct by the regularity of the 2--3-pinnate habit, the stem epidermis
weakly distinguished, leaf lobes more than three, leaf lamina divided to more
than one-half, eciliate laminal (disc) surfaces, cells thin-walled and weakly
striolate-verruculose throughout the plant, the septa of the cilia not
enlarged, and the lack of an eye-spot in the oil-bodies. The pale
pigmentation helps distinguish the species from the more highly colored mosses
and liverworts with which it is found in nature. |
