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BFNA Title: Herbertaceae |
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Herbertus – Herbertaceae XX. HERBERTACEAE
Müller Frib. ex
Fulford & Hatcher W. B. Schofield Plants pendent or
forming thick wefts; branches from axils of underleaves and sometimes also
those of leaves; often with ventral flagella. Leaves alternate, incubous, concave,
deeply 2-lobed, with a few teeth near base, lobes entire; underleaves similar
to leaves, deeply 2(--3)-lobed. Rhizoids
on base of underleaf. Specialized asexual reproduction absent. Gynoecium terminal on an ordinary leafy branch. Perianth often with subfloral
branches, well developed, strongly plicate, its mouth deeply lobed,
perigynium absent. Genera 2 (1 in
flora): circumtropical: North America, South America, Europe, Asia, Africa, Australia,
Pacific Islands. The Herbertaceae is predominantly epiphytic, but is also
found on soil and cliffs. The family extends northward to Arctic and
subarctic regions and southward to subantarctic
regions, in elevations from near sea-level to above 3000 m. Plants of Herbertaceae
are usually robust and rigid, 1--25 cm in secondary branch system in which
branches are occasionally lateral, but mainly postical
from underleaves. The leaves may be
nearly transverse, asymmetrically to symmetrically 2- or 3-lobed, lobes
narrowly lanceolate to broadly triangular, usually deeply divided;
underleaves symmetrical and transversely attached. Sexual condition is
dioicous; androecia are terminal initially but subterminal
with growth of androecial shoot, antheridia occur in axils of both lateral
and underleaves; the perianth is terminal, oblong-fusiform, 3--6 plicate, its
apex divided into 6--9 lobes. SELECTED
REFERENCES: Evans. A. W. 1917. Notes on the genus Herberta, with a revision of
the species known from Europe, Canada and the United States. Bull. Torrey Bot. Club 44: 191--222.
Feldberg, K, H. Groth, R. Wilson, A.
Schäfer-Verwimp and J. Heinrichs.
2004. Cryptic speciation in Herbertus (Herbertaceae,
Jungermanniopsida): Range and morphology of H. sendtneri inferred from nrITS
sequences. Plant Syst. Evol. 249:
247--261. Hodgetts,
N. G. 2003. Some synonyms of Herbertus dicranus (Taylor ex Gottsche et al.) Trevls. J. Bryol. 25: 138--140. Hong W. S., B. Deffinbaugh,
and B. Sparrow. 1993. The genus Herbertus in western North America. Lindbergia. 18: 41--45. Schuster, R. M. 1957. Notes on nearatic Hepaticae XV.
Herberta. Rev. Bryol. Lichénol. 26: 123--145. 1. HERBERTUS
Gray, Natur. Arrang.
Brit. Pl. 1: 705. 1821 * [For G. Herbert a patron of Pier’Antonio Micheli,
1679--1737] Plants beginning as a rhizomatous
irregularly branched system with rhizoids arising mainly from underleaves,
with leaves lacking well-defined vitta, this system
disappearing into the persistent secondary system in which the plants are
small to robust, rusty to reddish brown, 2--25 cm, suberect to pendulous,
forming moss-like turfs or rounded cushions of sparsely irregularly branched
stems, postical flagelliferous branches occasional
to frequent. Stems rigid to soft, often brittle. Leaves
in 3 rows, the ventral smaller than the two lateral, equally to somewhat
unequally 2-fid, usually with apparent forked vitta,
imbricate to somewhat postically secund and falcate or straight; base of leaf
sometimes auriculate; trigones large, sometimes nearly confluent; rhizoids
mainly confined to rhizomatous stems that precede the appearance of main
shoots, occasionally at the bases of underleaves; oil bodies 4--15+,
homogeneous. Specialized asexual
structures absent, some plant parts fragile. Sexual
condition dioicous; archegonia surrounded by a catkin-like plicate
perianth with laciniate mouth on short lateral branches when mature. Sporophyte
barely emergent from perianth; sporangium subspherical,
with 4--7 stratose wall, dividing regularly into 4 valves or
irregularly. Spores spherical. Species ca. 30 (3 in flora): nearly worldwide, circumtropical,
also interruptedly circumtemperate in both the
northern and southern hemisphere, extending to low Arctic and low Antarctic,
also islands in the Atlantic and the Pacific. The key to
species is based on presence of persistent secondary branches. 1. Lateral leaves
deeply 2-lobed to 2/3 leaf length, with lobes narrowly lanceolate, leaf not
strongly bulging at base . . . 1. Herbertus aduncus 1. Lateral leaves
2-lobed 1/3--1/2 leaf length, with lobes broadly triangular to broadly
lanceolate, leaf strongly bulging at base, especially on antical
side. 2. Leaves nearly
as broad as long, 2-lobed 1/3 or less leaf length; lobes broadly triangular,
decidedly asymmetric . . . Herbertus sendtneri 2. Leaves 2 times
as long as broad, 2-lobed 1/2 leaf length, base often bulging outward, lobes
lanceolate, symmetric or asymmetric . . . Herbertus dicranus 1. Herbertus
aduncus (Dickson) Gray, Nat. Arr. Brit. Pl. 1: 705. 1821 Jungermannia adunca Dickson, Plant.
Crypt. Fasc. 3: 12, plate 8, fig. 8. 1793 Plants brownish to red-brown,
sometimes dark green or wine-red, in polsters or
turfs. Stems erect to reclining, sometimes unbranched or irregularly
few-branched, but sometimes with numerous flagelliferous postical
branches, main stems 1--10 cm. Leaves deeply asymmetrically or
symmetrically 2-lobed with lobes narrow, 4--7 times as long as wide, vitta strong, extending to middle of leaf or beyond, of
elongate cells, leaves imbricate to secund postically, occasionally somewhat
squarrose. Sexual condition dioicous;
androecia intercalary, perigonial leaves less deeply lobed than most
leaves, not falcate; gynoecia
terminal, with innovations, becoming lateral with continued growth; perianth ovate,
narrowed to mouth, divided into 6 lanceolate lobes. Capsules mature
summer, confined to epiphytic
populations. Commonly epiphytic, also terrestrial or cliffs; forests
and peatland, 0--1000 m; Alta., B.C.; Alaska, Oreg., Wash. Herbertus aduncus is also found in
southeastern Asia (as subsp. schusteri H.A. Miller & G. Scott, and in western
Europe (as subsp. hutchinsiae
(Gottsche) Schuster, but these subspecies are
weakly distinguished, as is subsp. tenuis. Indeed, the literature concerning these variants
is extremely confusing, generated by polymorphism. In North America, sporophytes are known
only from the west coast, and even then they are confined to epiphytic
material and are not frequent except near the open coast. In consequence, clones are probably
frequent, and the eastern North American material presumably represents a
clone. Isolation modifies color,
stature, deepness of lobing and even the abundance
of flagelliferous branches. 1. Leaf bases
smooth-margined except for sessile slime-papillae. . . 1a. Herbertus aduncus subsp.
aduncus 1. Leaf bases
frequently with stalked slime papillae or with teeth terminated by a slime
papilla . . .1b. Herbertus aduncus subsp.
tenuis 1a. Herbertus aduncus
subsp. aduncus Plants commonly rusty brown, slender,
1--13 cm, in tall, forming turfs or cushions. Stems unbranched or few
branched, except for postical flagelliferous
branches. Lateral leaves erect
and nearly symmetric to asymmetric and secund, deeply divided with a narrow
V-shaped sinus; vitta forked and apparent, not
extending to apices of lobes. Sporophytes occasional on epiphytic plants,
maturing late spring--early summer. Commonly epiphytic, but also terrestrial
in peatland, talus slopes, cliffs, mainly near the coast; 0--1000 m; Alta.,
B.C.; Alaska, Oregon. Subspecies aduncus is endemic to Pacific North America.
It is relatively easy to determine in the field. Terrestrial plants can be confused with H.
dicranus, but the latter species usually has
bulging auricles and the lobes of lateral leaves are nearly as wide as long
with the sinus more U-shaped than V-shaped. 1b. Herbertus aduncus
subsp. tenuis (A. Evans) Miller & Scott Herberta tenuis A. Evans, Bull. Torrey Bot. Club 44: 219. 1917 Plants slender, yellow-
to brownish green, rarely vinaceous, forming mats
of suberect stems 0.5--4 cm deep, stems unbranched or irregularly and
sparingly branched, 0.5 mm in diameter (or less), of somewhat thick-walled
cells. Leaves 0.9--1 mm, with narrow but divergent lobes from a V-shaped
sinus 2/3--3/4 length of leaf, slightly or not curved, long-acuminate
0.6--0.7 x 0.15--0.17 mm, sometimes with basal teeth and slime papillae; vitta extending well into lobes, but never to apex. Specialized
asexual reproduction by brittle leaf lobes. Sporophytes
unknown, only female plants known.
Mainly on cliffs, shaded walls and ledges, also epiphytic on tree
trunks; low to high elevations (0 m in Nfld. but mainly above 2900 m); Nfld. and Labr. (Nfld.); Ga., N.C., N.J.,
N.Y., Penn., S.C., Tenn., Va., W.Va. Subspecies tenuis is endemic to eastern North
America and might be confused with occasional specimens of subsp. aduncus from western North America, but tends to
be considerably smaller and more slender than that taxon. 2. Herbertus
dicranus (Taylor) Trevisan, Mem. Real.
Inst. Lombardo Sci. Lett. Class. Sci. Mat. Nat.,
Sec. 3, 4: 397. 1877 Sendtnera dicrana Taylor, Syn. Hep., 239. 1845; H. sakuraii
subsp. arcticus Inoue & Steere Plants in tall or short,
loose or tight turfs of erect to suberect shoots, also as polsters,
1--20 cm, rusty brown to occasionally vinaceous or
nearly black. Stems unbranched to irregularly or densely branched, especially
with flagelliferous postical branches. Leaves
asymmetrically lobed, usually closely imbricate, falcate-secund
postically, especially on main shoots, almost transversely inserted, 2--3
times as long as wide, with lobes 1/2 or less of leaf length, broadly
lanceolate, leaf base on antical side usually
bulging to nearly auriculate, often with marginal downward pointing teeth and
slime papillae, vita extending 2/3 length of lobes, cuticle smooth. Specialized
asexual reproduction via brittle shoots.
Sexual condition diocous. Sporophytes
unknown in North America. Mainly terrestrial or on cliffs in North America
but epiphytic elsewhere, in hyperoceanic climates
in open coniferous forests, peatland and on cliffs; 0--500 m; B.C.; Alaska, Oreg., Wash.; Asia; Africa
(?); Pacific Islands. Included here as H.
dicranus are North American specimens
determined as H. himalayanus (Stephani) Herzog, H. sakuraii
(Warnstorf) Hattori and H. hawaiiensis H.
Miller. Herbertus dicranus shows
extreme variability throughout its range, with the material from Arctic
Alaska and interior northern B.C. (as H.
sakuraii subsp. arcticus) distinctive in its small
size, shallowly lobed leaves and alpine restriction. Specimens from peatland and open hyperoceanic forest can be unusually large (to more than
20 cm), form an extensive loose turf, and show considerable flagelliferous
branching. Material of open sites is usually little branched, and varies from
rusty red-brown to nearly black. The Oregon population (Saddle Mt.) is
smaller than most material other than that of Arctic and alpine sites, but
intergrades with material elsewhere.
Some specimens throughout the range resemble H. stramineus (Dumortier) Trevisan of Europe. 3. Herbertus sendtneri
(Nees) A.
Evans, Bull. Torrey Bot. Club. 44: 212. 1915 Schisma sendtneri Nees, Naturg.
Eur. Leberm. 3: 575. 1838 Plants in loose turfs or as isolated
shoots, yellow-green to brown, stems 6--10+ cm, unbranched or with occasional
postical flagelliferous branches, leaves
crowded. Leaves somewhat postically secund, 1--1.5 mm, broadly ovate with
broad lobes and sinus 1/3 or less the leaf length, and the leaves only
slightly longer than wide, symmetrically or asymmetrically lobed; underleaves smaller, more shallowly
and symmetrically 2-lobed; lobes are wider than long and thus broadly
triangular. Sporophytes
unknown. Terrestrial, shaded cliffs, shaded sites in tundra; 10--2000 m;
B.C.; Alaska; Europe (Alps); Asia (Himalayas). Herbertus sendtneri is readily determined in the field in most instances, but
there are morphs of both the other species that can resemble it in size and lobation. This species occurs mainly near the coast, and
may be alpine or subalpine, but only to 800 m in its southern range, and
extending lower to ca. 10 m in the Aleutian Islands. K. H. Feldberg et al. (2004) place material named as H. subdentatus (Stephani) Fulford into H. sendtneri,
but state that it is not identical with it.
Until this is resolved H. sendtneri
is treated as North Temperate in distribution. |
