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BFNA
Title: Hookeriaceae |
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XX.
HOOKERIACEAE Schimper Patricia M. Eckel Plants medium to large,
creeping, in mats or patches. Stems green,
hyalodermis and sclerodermis absent, stem central strand present. Leaves loosely complanate-foliate,
broad, apices flat, rounded-obtuse to sharply or broadly acute, often
asymmetric and somewhat dimorphic with dorsal leaves broader and more
symmetric than lateral leaves, margins unbordered, entire, plane; laminal
cells large, lax, smooth, uniform across the insertion and leaf base or
somewhat shorter than the medial; costa completely absent. Specialized asexual reproduction by
unbranched, uniseriate, subpapillose filaments among apical leaf rhizoids. Sexual condition autoicous [dioicous].
Seta red to reddish or blackish
brown, elongate, smooth. Capsule suberect
to pendulous, smooth, ovoid to cylindric; annulus distinct in one to several
rows of cells; exothecial cells strongly collenchymatous; operculum
conic-rostrate; peristome dark red, diplolepideous; exostome unfurrowed, with
a zigzag median line; endostome basal membrane high, processes more or less
perforate, extending just beyond the exostome teeth, cilia rudimentary or
absent. Calyptra mitriform,
multistratose at middle, smooth, naked, somewhat lobed at the base. Genera
2, species ca. 8 (1 genus, 2 species in the flora): worldwide in tropical and
temperate regions. The
Hookeriaceae, once of many genera (W. H. Welch 1966, 1976), is recently
recognized as comprised of two genera (B. Goffinet et al. 2008; W. Frey
2009): Crossomitrium, with 6 species
(B. H. Allen 1990), and Hookeria with
10, only two of which are well known (M. R. Crosby et al., Checklist of the
Mosses, unpublished, 1999). The absolute absence of a costa in the leaves is
a major character separating this family from closely related families. Crossomitrium, a neotropical South
American endemic genus, is absent in the floral area. Although considered to
be in the same family, the striking characteristics as detailed by B. H.
Allen 1990) of Crossomitrium separate
it from Hookeria including traits
of stem, leaf apices and margins, sexuality, seta ornamentation, exothecial
cell walls, peristome color, ornamentation of calyptra, type of asexual
reproduction, and habitat. Also, the stem cross section of Crossomitrium has a moderate scleroderm
with larger, thinner cortical cells toward the stem center. In Hookeria the section shows no
epidermal differentiation, the cells are large and lax throughout, and they
are also heteromorphic with smaller cells interspersed throughout the central
cylinder before the abrupt and large central strand, composed of very small
cells that appear to be somewhat colored. The two species of Hookeria in the flora have laminal
cells observable with a hand lens, being large, lax and broadly
oblong-hexagonal or rhomboidal. However, the cells of Crossomitrium species are all long-linear to vermicular with
comparatively thicker walls. SELECTED
REFERENCES Allen, B. H. 1990. A
revision of the Genus Crossomitrium (Musci:
Hookeriaceae). Tropical Bryology 2:3--34.
Frey, W., ed. 2009. Syllabus of Plant Families: A. Engler's Syllabus
der Pflanzenfamilien. Part 3. Bryophytes and seedless Vascular Plants. 1.
HOOKERIA Smith, conserved name. Trans. Linn. Soc. London 9: 275. 1808 * [For
William Jackson Hooker, 1785--1865, British bryologist and Director, Plants prostrate, dorsal and
ventral surfaces distinct relative to the ground, soft, flaccid, varnished-shiny
in incident light, appearing matt to the naked eye, in loosely foliate
whitish to light green or pale yellowish mats, somewhat contorted when dry,
sparsely and irregularly branched; paraphyllia absent, pseudoparaphyllia
reportedly filamentous or absent; rhizoids sparse, unbranched, hyaline to
brown. Stems 1--5(--7.5) cm,
fleshy and succulent, cortical cells in section large, concolorous,
heterogenous throughout, lacking a differentiated epidermis and sclerodermis,
central strand distinct, of markedly smaller, somewhat colored cells. Axillary hairs hyaline, 2--4-celled. Leaves 2--4.5(--6) mm, often radiculose at the leaf
tips with occasional filamentous gemmae, ovate, oblong-ovate, elliptic to
broadly lanceolate; apex rounded-obtuse to bluntly to broadly or sharply
acute; base somewhat decurrent at the margins; margins plane, entire,
borderless, with elongate cells, evenly thickened or slightly narrower in a
single marginal row; laminal cells 100--200(--250) \um, broadly
oblong-hexagonal or oblong-rhomboidal to shortly rectangular, becoming
smaller in all dimensions toward the apex or narrower on the margins,
sometimes heteromorphic with smaller cell-pairs scattered throughout the
leaf, thin-walled, pellucid. Sexual
condition autoicous and apparently dioicous. Seta stout, flexuose-curved, (0.8--)1--2(--2.5) cm. Capsules oblong-cylindric or
ellipsoid, 1.5--2 mm, neck short, containing phaneropore stomata; operculum
long-rostrate from a conic base; annulus of 1--2 rows of large cells, weakly
deciduous; exothecial cells strongly collenchymatous, subvesiculose; exostome
teeth dark red and cross-striolate basally, pale and papillose distally,
bordered and trabeculate; endostome pale, finely papillose, segments narrowly
open on the keel. Calyptra shortly
conic-mitrate, 2--2.5 mm. Spores small,
(10--)12--17 \um, spheric, smooth to scarcely or minutely papillose. Species
2(--8): e,w North America, Central America, n South America, Eurasia, Africa,
Atlantic Islands, Pacific Islands. Absence
of a costa, complete lack of a border, and very large leaf cells observable
with a hand lens readily separate species of Hookeria from other pleurocarpous mosses in the floral area. The
glossy, “lucent” or iridescent quality of the plants is associated with the
cell walls exhibiting a varnished appearance in incident light under a
microscope. The large lumina, however, render a dull or matt appearance to
the naked eye. When moistened, the plants appear almost transparent, or
pellucid. Paraphyllia and pseudoparaphyllia are absent in Crossomitrium (B. H. Allen 1990), but
according to B. Goffinet et al. (2008), pseudoparaphyllia in the family are
filamentous or absent; perhaps this applies only to the genus Hookeria. One species of Hookeria has a tropical distribution,
but also occurs in the temperate zone, the other is a north temperate species
of both the New and Old Worlds. 1.
Leaves acute, laminal cells (except rhizoid initials at the apex) more or
less homogenous; capsules not or little contracted below the mouth when dry;
elongate marginal laminal cells in a single row, narrower than median
cells……………………..........................1. Hookeria
acutifolia 1.
Leaves obtuse, laminal cells with scattered pairs of smaller cells, one
smaller relative to the other and quadrate, resembling the rhizoid initials
at the apex; capsules strongly contracted below the mouth when dry; elongate
marginal laminal cells equal in width to median cells .................... 2. Hookeria lucens 1. Hookeria acutifolia Hooker &
Greville, Edinburgh J. Sci. 2: 225. 1825 Pterygophyllum
acutifolium (Hooker
& Greville) Müller Hal., Linnaea 21: 194. 1841; Hookeria? sullivantii Müller Hal. in Lesquereux & James Leaves acute, laminal cells
(except rhizoid initials at the apex) more or less homogenous; elongate
marginal cells in a single row, narrower than median cells. Capsules not or little contracted
below the mouth when dry. Capsules
mature late fall--spring. Steep to vertical banks to crevices and recesses in
cold streams, gullies, ravines, mouths of caves, ledges and under overhanging
cliffs, deep shade of evergreens and mixed hardwood forests, by waterfalls,
gneiss, shale, conglomerates but mostly on sandstone, in coves, low cloud
forests, occasionally with Bryoxiphium,
Trichomanes, Vittaria spp.;
550--2500 m; B.C.; Ala., Ark., Conn., Ga., Ill., Ind., Ky., N.C., Ohio, Pa.,
S.C., Tenn., Va., Wash., W.Va.; Mexico; Central America; West Indies; N.C.
South America; e Asia; Africa; Pacific Islands (Hawaii). Hookeria
acutifolia is a species of warm-temperate and tropical distribution,
being rare and scattered in eastern North America, and disjunct to When
the leaf apex lacks rhizoids, the apex is sharply acute and tipped with a
small sharp apical cell, but when rhizoids are present, the apical cells are
digested and the apex becomes erose and bluntly rounded-acute, but never
smoothly rounded-obtuse as in H. lucens. Hookeria
acutifolia was reported as autoicous in the moss flora of 2. Hookeria lucens (Hedwig) Smith, Trans.
Linn. Soc. London 9: 275. 1808 Hypnum lucens Hedwig, Sp. Musc.
Frond., 243. 1801 Leaves obtuse, laminal cells
with scattered pairs of smaller cells, one smaller relative to the other and
quadrate, resembling the rhizoid initials at the apex; elongate marginal
laminal cells equal to width of median cells. Capsules strongly contracted below the mouth when dry. Capsules
mature late fall--spring. Coastal islands and adjacent mainland, ravines,
pools near rivers, swampy lake margins, raised bogs in peaty muck, wet
evergreen woods of Tsuga,
Chamaecyparis, Alnus, forests
of Sequoia sempervirens, coastal
Sitka spruce forests, old logs in heathland; 0--500 m; B.C.; Alaska, Calif.,
Idaho, Oreg., Wash.; Europe; Asia (Caucasus, Turkey); Atlantic Islands
(Faeroe Islands, Madeira Islands). A.
J. E. Smith (2004) reported that in REFERENCES
CITED Bang-juan, Lin and B.
C. Tan 2002. Hookeriaceae. In: Bowers, F. D. 1994. Hookeria
In: The Moss Flora of Crum, H. A. and L. E.
Anderson. 1981. Mosses of Smith, A. J. E. 2004.
The Moss Flora of |
