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BFNA Title: Radulaceae
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XXX. RADULACEAE
(Dumortier) Müller Frib. David M. Krayesky Lorinda Leonardi Jerry G. Chmielewski Plants in thin to dense mats; Radula-type
branching, devoid of collars, arising from immediately behind the leaf in which
the keel of the leaf is usually adnate with the base of each branch;
regularly or irregularly 1--3 pinnate; without flagella; some species
containing microphyllous branches [Lejeunea-type branches]. Leaves alternate,
incubous, dorsal lobe plane or adaxially concave, entire; ventral lobe (lobule) small, folded under the
larger dorsal lobe, attached to stem and lobe. Underleaves
absent. Leaf cells with or without
trigones; usually one large granular oil body per cell. Rhizoids confined
to center of lobule and always absent from the stem. Specialized asexual
reproduction in some species either as multicellular gemmae or caducous
leaves. Androecium terminal or
intercalary on thallus. Gynoecium terminal on stem or lateral
branches. Perianth often subtended by 1 or 2 subfloral branches, well
developed, dorsiventrally flattened, mouth broad, perigynium absent. Sporophyte with ovoid-cylindric
capsules, lines of dehiscence reaching the base. Genus 1: Nearly
worldwide in distribution. XX. RADULA Dumortier,
Comment. Bot., 112. 1822 [Latin radula,
scraper, alluding to the flat tip of the perianth occasionally recurved
and similar to a scraping iron] Plants yellowish to
yellow-green to bright, deep, dull or olive green, and sometimes with a brownish
cast; prostrate. Stem cortical and medullary cells similar in size with medullary
being somewhat larger, with or without differentiated cortex, some species
with thick-walled cortical cells and thin walled medullary cells, other
species with cortical and medullary cells that are either both thin or
thick-walled; branches regularly to irregularly pinnate (plumose in some
species); microphyllous branches present in some species. Leaves subcontinuous to
imbricate, complicate-bilobed; dorsal lobe ovate to suborbicular; lobule (ventral lobe) subquadrate or
triangulate, with a long, rounded keel. Leaf
cells hexagonal; thin to thick-walled, trigones small to intermediate to
bulging if present. Oil bodies
papillose to granular-botryoidal, ellipsoidal to ovoid to round; 15--20 x
9--12 /um. Rhizoids hyaline to yellow brown, only occasionally present on
basal portion of lobules. Specialized asexual reproduction in
some species by multicellular discoid gemmae of dorsal lobe margins (small to
large in size) or caducous dorsal lobes.
Sexual condition monoicous
(paroicous, autoicous, or heteroicous), dioicous. Androecia
bracts imbricate, (2--)3--12(--35) pairs, dorsal
lobes of bracts generally smaller than vegetative dorsal lobes, ventral lobes
of bracts approaching size of the corresponding dorsal lobe; antheridia
generally solitary. Gynoecia complicate-bilobed, 1(--2)
pairs, dorsal lobes of bracts generally smaller than vegetative dorsal lobes,
ventral lobes of bracts approaching size of the corresponding dorsal lobe;
archegonia 5--12. Perianth 1--3.0 x 0.5--1.3 mm; with or without perigynium,
oblong, compressed; lateral margins keeled or rounded; mouth shallowly
2-labiate, entire to dentate; 1-stratose throughout except near base, and
2-stratose along keels. Sporophyte seta
cross section 10--12 cells wide; without differentiated epidermis; capsule
0.8--0.9 x 0.3--0.5 /um; ovoid-cylindric, 4-valved, capsule wall
2-stratose. Elaters blunt at ends, 2(--3)-spiraled, spirals 2--3 /um wide,
yellow-brown or greenish-brown. Spores unicellular to multicellular,
granulate, finely papillate or verruculose, pale yellow brown or greenish
brown. Species
approximately 250 (15 in the flora): North America; West Indies; Bermuda;
Central America; South America; Europe; Asia; Africa; Atlantic Islands;
Indian Ocean Islands; Pacific Islands; Australia. SELECTED
REFERENCES Breil, D. A. 1970.
Liverworts of the Mid-Gulf Coastal Plain. Bryologist 73:
409--491. Castle, H. 1950. A Revision of the Genus Radula Part II. Subgenus Acroradula Section 2. Amentulosae. Bryologist 53: 253--275. Castle, H. 1968. Radula (L.) Dumortier.---A synopsis of the taxonomic revision of the
genus. Rev. Bryol. Lichénol. 36: 5--44. Dauphin, G., R. P. Wunderlin,
F. B. Essig, and P. G. Davison. 2011. A checklist of the liverworts (Marchantiophyta) and hornworts (Anthocerotophyta)
of Florida. J. Bot. Res. Inst. Texas. 5: 773--814. Devos, N., M. A.
M. Renner, S. R. Gradstein, J. Shaw, and A. Vanderpoorten. 2011.
Molecular data challenge traditional subgeneric
divisions in the leafy liverwort Radula.
Taxon 60: 1623--1632. Frye, T. C. and
L. Clark. 1946. Hepaticae of North
America. Univ. Washington Publ. Biol. 6: 688--709. Schuster, R. M. 1980.
The Hepaticae and Anthocerotae of North America east of the hundredth
meridian. New York, 4: 566--651. Söderström, L.,
A. Hagborg, M. von Konrat, S. Bartholomew-Began, D.
Bell, L. Briscoe, E. Brown, D. C. Cargill, D. P. Costa, B. J.
Crandall-Stotler, E. D. Cooper, G. Dauphin, J. J. Engel, K. Feldberg, D.
Glenny, S. R. Gradstein, X. He, J. Heinrichs, J. Hentschel,
A. L. Ilkiu-Borges, T. Katagiri, N. A.
Konstantinova, J. Larraín, D. G. Long, M. Nebel, T. Pócs, F. Puche, E.
Reiner-Drehwald, M. A. Renner, A. Sass-Gyarmati, A.
Schäfer-Verwimp, J. S. Moragues, R. E. Stotler, P. Sukkharak, B. M.
Thiers, J. Uribe, J. Váňa, J. C. Villarreal, M. Wigginton, L. Zhang, and R. Zhu. 2016.
World Checklist of Hornworts and Liverworts. PhytoKeys
59: 1--828. Stotler,
R. E. and B. J. Crandall-Stotler. 1977. A checklist of the liverworts and
hornworts of North America. Bryologist 80: 405–428. Yamada, K.
1979. A revision of Asian taxa
of Radula, Hepaticae. J. Hattori
Bot. Lab. 45: 201--322. 1.
Plants epiphyllous; with a tendency to possess
slender triradiate trigones; gemmae often present
(large, 1/3--3/4 the size of the dorsal lobe of the leaf)……….….. 1. Radula flaccida 1.
Plants terricolous, epicortic, epixylic, or epilithic; slender triradiate
trigones never present; gemmae absent to copious (less than 1/5 the size
of the dorsal lobe of the leaf). 2.
Dorsal lobes with a strong tendency to be caducous. 3.
Thallus lacking or containing a few leaves with a
falcate leaf stance; rhizoids often abundant; heteroicous……………………..………….....………
2. Radula obconica 3.
Thallus containing many leaves with a falcate leaf
stance; rhizoids absent to sporadic; dioicous. 4.
Lobule triangulate; androecia intercalary; plants
sometimes yellow-green; plants never with a brownish
cast.................................................... 3. Radula sullivantii 4.
Lobule subquadrate; androecia terminal; plants
never yellow-green; plants occasionally with a brownish cast…...……….....…………... 4. Radula
floridana 2.
Dorsal lobes never caducous. 5. Leaves producing gemmae (often to rare). 6. Mature stems hidden in
postical (ventral) view by lobules (ventral lobes) of thallus. 7. Stems with
differentiated cortex; lobule base strongly auriculate; gemmae rare…..……………………………………….……….…...... 5. Radula voluta 7. Stems without differentiated cortex; lobule base not to slightly
auriculate; gemmae common…………………………..………....…. 6. Radula quadrata 6. Mature stems not hidden
in postical (ventral) view by lobules (ventral lobes) of thallus. 8. Monoicous (paroicous)..…………...………………...… 7. Radula
complanata 8. Dioicous. 9. Thallus never
with a bronze cast; temperate to Arctic…………………. …………………….………………….……..… 8. Radula lindenbergiana 9. Thallus with a
tendency to have a bronze cast; temperate to subtropic…
…………………….....……………………………….. 9. Radula australis 5. Leaves never producing
gemmae. 10. Microphyllous branches
present. 11. Plants less than 12 mm
in length; leaves distant; without a differentiated cortex; monoicous
(autoicous); Arctic……………..……. 10. Radula
prolifera 11. Plants more
than 12 mm in length; with a differentiated cortex; dioicous; leaves
imbricate; Boreal/temperate……….....……....…….11. Radula brunnea 10. Microphyllous branches absent. 12. Plants with a very strong tendency to produce primary
branches associated with each leaf along the main stem, thus plumose
(frond-like) in habit……... …….....…………………………………..….………… 12. Radula obtusiloba 12. Plants lacking a tendency to produce primary branches
associated with each leaf along the main stem, thus not plumose (frond-like)
in habit. 13. Stems without
differentiated cortex leaf cells without conspicous
trigones (trigones absent to minute)……………….……......... 13. Radula bolanderi 13. Stems with differentiated cortex; leaf cells with small
to conspicuous trigones. 14. Mature plants usually less than 55 mm in length; dorsal
lobe base slightly auriculate; Appalachians...……….…....…... 14. Radula tenax 14. Mature plants usually greater than 55 mm in length;
dorsal lobe base moderately auriculate; coastal Pacific Northwest...............................
……………………………………...………….. 15. Radula
auriculata 1. Radula flaccida Lindenberg & Gottsche., ex Gottsche, Lindenberg & Nees, Syn. Hepat., 726. 1847 Plants light green, ca.
4--6.1 x 0.7--1.1 mm; prostrate to substrate; epiphyllous; growing in mats. Stem 47--55 /um in diameter, cortex
and medulla 4--5 cells in width, without a differentiated cortex; irregularly
pinnately branched, not plumose; without microphyllous branches. Leaves
persistent; not undulate, imbricate, slightly falcate; dorsal lobe
ovate, adaxially slightly concave to nearly plane, 0.6—1(--1.2) x
0.5—0.9(--1) mm; base very weakly auriculate; lobule (ventral lobe) united for about 0.75--0.9 the length along stem from the
base of the keel to the opposite margin of the lobule, flat and convex
postically, apex often recurved especially at tip, not undulate, rhizoids
sporadic to somewhat common, rhombic, (0.2--)0.3--0.4 x 0.2--0.4 mm, not
overlapping and hiding stem, apex obtuse with a bluntly angular tip sometimes
forming a short apiculus, base not to slightly auriculate. Leaf cells at margins 9--14
x 9--16 /um, at midleaf 8--19 x 9--16 /um; trigones absent or slenderly triradiate (with
occasional thickenings between trigones); oil bodies conspicuous, 2 per cell
(occasionally with accompanying oil bodies of smaller size). Asexual
reproduction by cauducous leaves absent; large
regular discoid gemmae, 474--568 x 512--613(--800) /um, generally 1/3--3/4 size of dorsal
lobe, not numerous, 1--3 per dorsal lobe, restricted to anterior margin. Sexual
condition dioicous. Androecia on main stem or lateral
branches, bracts imbricate, usually in 5--12 pairs, spicate. Gynoecia
terminal on main stem. Perianth 1--1.5 x 0.5 mm
trumpet-shaped, shallowly 2-labiate, slightly sinuate-crenate. Sporophyte
capsule ovoid. Spores unknown. Leaves of
flowering evergreens, reported to occur on the fronds of ferns, deep shade
and humid environments; low to moderate elevations; Fla.; Mexico; West
Indies; Central America; South America; Atlantic Islands, Africa, Indian
Ocean Islands. Radula flaccida is restricted to both tropical and subtropical regions of
the world. R. M. Schuster (1980) indicated the species in all likelihood has
become extirpated from Florida, and hence is no longer found in North America
north of Mexico. G. Dauphin et al.
(2011) have confirmed the occurrence of R.
flaccida in Florida from a 2009 collection, Buck 54479 (NY). We agree that the Buck collection is R. flaccida. The collection in question was not available
for study---the determination, however, was made by B. M. Thiers, and as this
is the only taxon of Radula from
the United States that is epiphyllous we believe it could be nothing but R. flaccida. Radula
flaccida remains a taxon of rare occurrence in
North America north of Mexico. 2. Radula obconica Sullivant,
Manual (ed. 1): 688. 1848 Plants yellow-green to
olive-green, ca. 9--19 x 0.9--1.3 mm; prostrate; epilithic or epicortic; growing in mats
or singly among other bryophytes. Stem 81--115 /um in diameter, cortex
and medulla 6--10(--11) cells in width, without a differentiated cortex;
irregularly pinnately branched, not plumose; without microphyllous
branches. Leaves with a tendency to be caducous; not undulate, contiguous
to slightly imbricate, not falcate to occasional slightly falcate; dorsal lobe
ovate, adaxially concave, 0.5--0.8 x 0.3--0.6 mm; base weakly subauriculate; lobule (ventral lobe) united for 0.35--0.5 the length along stem from the base of
the keel to the opposite margin of the lobule, convex postically, apex appressed to dorsal lobe, not
undulate, rhizoids often common and occasionally sporadic, subquadrate-rotundate, 0.2--0.3 x 0.2--0.3 mm, not overlapping and
hiding stem, apex obtuse often with bluntly angular tip and occasionally
slightly acuminate, base not auriculate. Leaf cells at margins 10--12 x 10--12 /um, at midleaf 9--17 x 11--18
/um; trigones absent; oil bodies conspicuous, 1 per cell. Asexual
reproduction by caducous leaves (dorsal lobes); gemmae absent. Sexual
condition heteroicous, usually fertile.
Androecia terminal on short
lateral branches or terminal on main stem, bracts imbricate, usually in 3--5
pairs, stoutly spicate. Gynoecia terminal on main stem or
lateral branches, bracts erect or suberect, dorsal lobe ovate to obovate and
ventral lobe subquadrate. Perianth 1.9--2.4 x 0.6--0.7 mm,
clavate to obconic, shallowly 2-labiate, lips entire-margined. Sporophyte
capsule ellipsoid. Spores minutely
papillate, pale yellow brown, unicellular, 35--43 /um. Bark of trees or rocks of shaded humid sites; low to
moderate elevations; Ont., Que.; Ala., Ark., Conn., D.C., Fla., Ga., Ind.,
Ill., Ky., La., Maine, Mass., Mich., Minn., Miss., N.H., N.J., N.Y., N.C.,
Ohio, Okla., Pa., S.C., Tenn., Vt., Va., W.Va., Wis. Radula obconica appears to be restricted to eastern North America. It occurs in temperate forests, and is
present in the very southern portion of the boreal forests of North
America. 3. Radula
sullivantii Austin, Bull.
Torrey Bot. Club 6: 19. 1875 E Plants yellow-green to
dull green (occasionally dark green in shade), ca. 10--16 x 1.2--1.5 mm;
prostrate; epilithic; growing in mats
or singly among other bryophytes. Stem 88--103 /um in diameter, cortex
and medulla 7--8 cells in width, without a differentiated cortex; irregularly
pinnately branched, not plumose; without microphyllous branches. Leaves
with a tendency to be caducous; not undulate, distant to contiguous, widely
spreading and falcate; dorsal lobe ovate to obovate, adaxially nearly concave to
plane, 0.4--0.6 x 0.2--0.6 mm; base very weakly auriculate; lobule (ventral
lobe) united for most of its length with stem, not undulate, rhizoids absent
to sporadic, triangulate, 0.2--0.3 x 0.2--0.3 /um, not overlapping and hiding stem, anticlinal margin often
with a short-acuminate recurved tip, base not auriculate. Leaf cells at margins 9--15
x 9--15 /um, at midleaf 8--13 x 8--13 /um; trigones small and concave-sided;
oil bodies conspicuous, 1 per cell (occasionally with an accompanying oil
body of smaller size). Asexual reproduction by caducous
leaves (dorsal lobes); gemmae absent. Sexual condition dioicous. Androecia
generally intercalary on lateral branches or main stem, bracts imbricate,
usually in 2--4 pairs. Gynoecia unknown. Perianth
unknown. Sporophyte unknown. Spores unknown. Deep shade on wet
to damp rocks along streams, and ledges near waterfalls, occasionally shallow
soil over rock; moderate elevations; Ga., Ky., N.C., S.C. Radula
sullivantii is endemic to the southeastern United States. It occurs predominately as a montane
species inhabiting the coves and gorges of the southern Appalachians. Previously, the species had also been
reported from the lowlands of the Gulf Coast Plain of the southeastern United
States (D. A. Breil 1970). R. M. Schuster (1980) suggested the previous reports of R. sullivantii
from Tennessee were actually R. obconica. We
believe there is enough evidence to support the Schuster (1980) hypothesis
and hence, conclude that the Tennessee occurrences of R. sullivantii were misidentifications. Furthermore, R.
M. Schuster (1980) reported that the occurrences of R. sullivantii from
Florida, Alabama, and Louisiana were probably R. floridana Castle. If R.
sullivantii is indeed a montane species strictly occurring on rock, sensu
Schuster (1980), it would suggest the collections identified from the Gulf
Coast Plain are misidentified and not R.
sullivantii. We find that there is
significant support for Schuster’s (1980) hypothesis as to the distribution
of this species. Collections of R. sullivantii from the Gulf Coast
Plain were examined in this study.
These aforementioned collections were determined to be either R. floridana
or R. obconica,
namely, Schuster 20197 (F) and Schuster A--117 (F), respectively. Thus, we believe that R. sullivantii is endemic to the southern Appalachians. 4. Radula floridana Castle, Rev.
Bryol. et Lichén.
36(1--2): 1. [1968] 1969 Plants bright or deep to
dull green, very occasionally with
a brownish cast, ca. 9.5--22 x 1.7--2.1 mm; prostrate; epilithic (limestone) or epicortic; growing in mats
or singly among other bryophytes. Stem 130--168 /um in diameter, cortex
and medulla 7--11 cells in width, without a differentiated cortex;
irregularly pinnately branched, not plumose; without microphyllous
branches. Leaves with a tendency to be caducous; not undulate, contiguous
to slightly imbricate, widely spreading and falcate; dorsal lobe
oblong-ovate, adaxially slightly concave to nearly plane, 0.9--1.2 x 0.7--0.9
mm; base very weakly auriculate; lobule (ventral lobe) united for 0.5--0.65 the length along stem from the base of
the keel to the opposite margin of the lobule, convex postically, apex appressed to dorsal lobe, not
undulate, rhizoids sporadic, cuneate-subquadrate, 0.3--0.6 x 0.3--0.4 mm, not
overlapping and hiding stem, apex obtuse forming a bluntly angular forming
tip that is occasionally somewhat rounded, base slightly auriculate. Leaf cells at margins 9--10
x 10--12 /um, at midleaf 10--24 x 11--25 /um; trigones minute and
inconspicuous; oil bodies conspicuous, 1 per cell (occasionally with an
accompanying oil body of smaller size or two of equal size). Asexual
reproduction by caducous leaves (dorsal lobes); gemmae rarely produced
and often absent. Sexual condition dioicous.
Androecia terminal on
lateral branches or main stem, bracts imbricate, usually in 5--10 pairs,
spicate. Gynoecia terminal on main stem or primary branches, bracts erect,
dorsal lobe ovate to obovate and ventral lobe subquadrate. Perianth
0.7--1.5 x 0.4--0.6 mm subcompanulate, compressed,
2-labiate. Sporophyte unknown. Spores unknown. Dense shade of forests on limestone or on roots, twigs, or
bark at the base of tree trunks; low to moderate elevations; Ala., Fla.,
Miss., La.; West Indies. Radula floridana is restricted to the New World occurring in tropical or
subtropical localities. In United
States it has a restricted distribution to that of the Gulf Coast
region. G. Dauphin et al. (2011)
reported that R. floridana,
a species that was reported by R. M. Schuster (1980) to be restricted to the
extreme southeastern United States, Bahamas, and Cuba, is actually
conspecific with the more widespread R.
javanica of Central America, South America,
Asia, and Pacific Islands. There is
some plausible evidence to support this synonymy, as K. Yamada (1979)
conceived R. javanica
as a very plastic species, as both leaf lobes and lobules show a wide range
in size and shape. However, plants of R. floridana
appear significantly smaller in size than what is reported in R. javanica. N. Devos et al.
(2011) also demonstrated. based on a single sample
each of R. javanica
and R. floridana,
that there is genetic divergence between these two species. L. Söderström et
al. (2016) code both R. javanica and R.
floridana as taxa in which a knowledge problem
exists. Until a detailed revisionary
study is conducted to resolve this species complex we will continue to treat
both R. javanica
and R. floridana
as distinct species. 5. Radula voluta Taylor ex Gottsche, Lindenberg & Nees, Syn. Hepat.,
255. 1845 Plants pale
yellow-green, ca. 19--50 x 1.9--2.8 mm; prostrate; epilithic; growing in mats or singly among other bryophytes. Stem
240--303 /um in diameter, cortex and medulla 10--13 cells in width, with a
differentiated cortex; irregularly pinnately branched, not plumose; without
microphyllous branches. Leaves persistent; slightly undulate,
contiguous to slightly imbricate, slightly falcate; dorsal lobe ovate, adaxially concave to
nearly plane, 1.0--1.6 x 0.7--1.5 mm; base slightly auriculate; lobule
(ventral lobe) united for about
0.3--0.65 the length along stem from the base of the keel to the opposite
margin of the lobule, with a circinate line of insertion, depressed and concave
at its center, apex appressed to dorsal lobe, strongly undulate, rhizoids
sporadic, subquadrate-rotundate, 0.4--0.8 x 0.5—0.8
mm, overlapping and hiding stem, apex obtuse with a bluntly angular to
slightly rounded tip, occasionally tip shortly acuminate, base strongly
auriculate. Leaf cells at margins 10--14 x 10--16 /um, at midleaf 10--22 x 11--25
/um; trigones minute and inconspicuous or absent; oil bodies conspicuous, 1
per cell (occasionally with 1--2 accompanying oil bodies of smaller
size). Asexual reproduction by cauducous
leaves absent; irregular discoid gemmae from marginal or median cells of
thallus lobes, rarely produced and often absent, less than 1/5 the size of
dorsal lobe. Sexual condition dioicous; usually sterile. Androecia
terminal on lateral branches and occasionally intercalary on stem, bracts
imbricate, usually in 3--4 pairs, spicate.
Gynoecia terminal on
branches, bracts convergent, dorsal lobe ovate and ventral lobe rhomboidal,
oblong, or lingulate. Perianth unknown. Sporophyte
unknown. Spores unknown. Base-rich damp
rocks in shaded riparian areas; low to high elevations; N.C., Tenn.; Central
America; South America; Europe. Radula voluta occurs in both the New and Old World. Throughout its range, it is quite uncommon. 6. Radula quadrata Gottsche ex Gottsche, Lindenberg
& Nees, Syn. Hepat.,
255. 1845 Radula andicola Stephani; R. mollis Lindenberg & Gottsche in Gottsche, Lindenberg & Nees Plants yellow-green, ca.
19.5--36.1 x 1.7--2.1 mm; prostrate; epicortic or epilithic; growing in mats
or singly among other bryophytes. Stem 121--183 /um in diameter, cortex
and medulla 12--18 cells in width, without a differentiated cortex; regularly
pinnately branched, not plumose; without microphyllous branches. Leaves
persistent; not undulate, closely imbricate, not to slightly falcate; dorsal lobe ovate to subrotundate, adaxially concave, 1--1.3 x 0.9--1 mm; base
slightly cordate to auriculate; lobule (ventral lobe) united for about 0.65 the length along stem from the base
of the keel to the opposite margin of the lobule, with a slightly arched line
of insertion, slightly convex,
not appressed to dorsal lobe, undulate, rhizoids often common, subquadrate,
0.4--0.7 x 0.4--0.5 mm, overlapping and hiding stem, apex obtuse with a
slightly rounded tip, base auriculate.
Leaf cells at margins 10--16
x 10--16 /um, at midleaf 11--21 x 11--24 /um; trigones small and
inconspicuous; oil bodies conspicuous, 1 per cell (occasionally with an
accompanying oil body of smaller size).
Asexual reproduction by cauducous leaves absent; irregular discoid gemmae usually
present and copious, less than 1/5 the size of dorsal lobe. Sexual
condition dioicous; usually sterile.
Androecia terminal on
branches, bracts imbricate, usually in 4--12 pairs, spicate. Gynoecia
terminal on stem or branches, bracts convergent, dorsal lobe obovate and
ventral lobe quadrate. Perianth 3 x 1.3 mm broadly
truncate-clavate, somewhat 2-labiate. Sporophyte unknown. Spores
unknown. Bark of trees,
exposed and sheltered localities, moist rocks in gorges; low to high
elevations; Ala., Ark., D.C., Fla., Ga., La., N.C., S.C., Tenn., Va., W.Va.;
Mexico; West Indies; Central America; South America. Radula quadrata currently appears to be restricted to the New World, in
the Neotropics and the southeastern United States. 7. Radula complanata (Linnaeus)
Dumortier, Syll. Jungerm. Europ., 38. 1831 Jungermannia complanata Linnaeus, Spec. Pl., 1133. 1753 Plants bright
yellow-green, ca. 6.8--14.9 x 1.3--1.9 mm; prostrate; epicortic, epilithic, or terricolous; growing in mats or singly among other bryophytes. Stem
105--164 /um in diameter, cortex and medulla 5--7 cells in width, without a
differentiated cortex; irregularly branched, not plumose; without
microphyllous branches. Leaves persistent; not undulate,
slightly to strongly imbricate, very slightly falcate; dorsal lobe ovate, adaxially
concave, 0.7--1.1 x 0.5--0.9 mm; base very weakly auriculate; lobule (ventral
lobe) united for about 0.65--0.75 the length
along stem from the base of the keel to the opposite margin of the lobule, flat, appressed
to dorsal lobe, not undulate, rhizoids sporadic, subquadrate, 0.4--0.5 x
0.3--0.4 mm, not overlapping and hiding stem, apex obtuse with a bluntly
angulate or rounded tip, base slightly auriculate. Leaf cells at margins 10--14
x 12--19 /um, at midleaf 14--31 x 13--34 /um; trigones small; oil bodies
conspicuous, 1 per cell (occasionally with 1--2 accompanying oil bodies of smaller
size). Asexual reproduction by cauducous
leaves absent; irregular discoid gemmae, usually present and copious, less
than 1/5 the size of dorsal lobe. Sexual condition paroicous, often
fertile. Androecia usually terminal on leading branches or main stem,
bracts imbricate, usually in 1--2 pairs.
Gynoecia usually terminal
on leading branches or main stem, bracts erect ventral lobe approaching size
of dorsal lobe. Perianth 1.5--2(--2.5) x 0.7--0.9 mm oblong, usually
weakly 2-labiate, entire or sinuose. Sporophyte capsule oblong-ovoid. Spores
granulate, pale yellow brown, unicellular, 25--35 /um. Acid- to
base-rich substrates; Greenland; St. Pierre and Miquelon; Alta., B.C., Man.,
Nfld. and Labr. (Nfld.), N.S., Ont., Que.; Ala., Ariz., Calif., Colo., Conn.,
D.C., Fla., Ga., Ill., Ind., Iowa, Ky., La., Maine, Md., Mass., Mich., Minn.,
Miss., Mo., Mont., N.H., N.J., N. Mex., N.Y., N.C., Ohio, Oreg., Pa., R.I.,
S.C., Tenn., Utah, Vt., Va., W.Va., Wash., Wis., Wyo.; Mexico; West Indies;
South America; Europe; Asia; Africa; Atlantic Islands; Pacific Islands. Radula complanata is a widespread species, but appears to be nearly absent
from the tundra sensu stricto and
the lowlands of the tropics. It occurs
in a variety of habitats including oceanside
cliffs, peatlands, woodlands, waste places, riparian areas, and subalpine
crags. According to R. M. Schuster (1980,) the reports of R. complanata
in Florida require further verification.
Presently, the species has not been reported in Central America, but
as it is found throughout North and South America, we would expect it to
occur in Central America as well. 8. Radula lindenbergiana Gottsche ex C. Hartman, Handb. Skand. Fl. (ed. 9) 2:
98. 1864 Radula complanata ssp. lindenbergiana (Gottsche ex C.
Hartman) R. M. Schuster Plants pale to dark
green or yellow-green, ca. 9.1--14.8 x 1.2--1.9 mm; prostrate; epicortic or epilithic; growing in mats
or singly among other bryophytes. Stem 103--125 /um in diameter, cortex
and medulla 5--7 cells in width, without a differentiated cortex; irregularly
branched, not plumose; without microphyllous branches. Leaves
persistent; slightly to strongly imbricate, very slightly falcate; dorsal lobe ovate, adaxially
concave, 0.8--0.9 x 0.6--0.8 mm; base very weakly auriculate; lobule (ventral lobe) united for about 0.65--0.75 the length along stem from the
base of the keel to the apex of the lobule, flat, appressed to dorsal lobe, not undulate, rhizoids
sporadic, subquadrate, 0.4--0.5 x 0.3--0.5 mm, not overlapping and hiding
stem, apex obtuse to angulate, base slightly auriculate. Leaf cells at margins 12--22
x 13--19 /um, at midleaf 15--27 x 14--30 /um; trigones small; oil bodies
conspicuous, 1 per cell (occasionally with 1--2 accompanying oil bodies of
smaller size). Asexual reproduction by cauducous
leaves absent; irregular discoid gemmae usually present and copious, less
than 1/5 the size of dorsal lobe. Sexual condition dioicous, rarely
fertile. Androecia usually terminal on leading branches or main stem,
bracts imbricate, usually in 3--5 pairs spicate. Gynoecia
usually terminal on leading branches or main stem, bracts erect ventral lobe
approaching this size of dorsal lobe. Perianth 1.5 x 3.0 mm oblong, usually
weakly 2-labiate. Sporophyte capsule oblong--ovoid.
Spores granulate, yellow
brown, unicellular, 25--38 /um. Dry to moist
rocks, very occasionally bark of trees, when epilithic
found growing in forested localities, flooded rocks of streams, and sheltered
rock faces; low to high elevations; Greenland; Alaska, Tenn.; Europe; Asia;
Africa; Atlantic Islands. 9. Radula australis Austin, Bot.
Bull. (Hanover) 1: 32. 1876 E Radula caloosiensis Austin; R. langloisii Castle Plants yellow-green occasionally
with a bronze to brownish cast, ca. 8.8--17.5 x (1--)1.3--2.1
mm; prostrate; epicortic; growing in mats
or singly among other bryophytes. Stem 95--109 /um in diameter, cortex
and medulla 6--7 cells in width, without a differentiated cortex; irregularly
branched, not plumose; without microphyllous branches. Leaves
persistent; not undulate, moderately imbricate, somewhat to
slightly falcate; dorsal lobe ovate, adaxially concave, 0.5--1.1 x 0.4--0.7
mm; base very weakly auriculate; lobule (ventral lobe) united for about 0.65 the length along stem from the base
of the keel to the opposite margin of the lobule, flat, appressed
to dorsal lobe, not undulate, rhizoids sporadic, subquadrate, 0.2--0.3 x
0.2--0.4 mm, not overlapping hiding stem, apex obtuse with a bluntly acute
tip, base slightly auriculate. Leaf cells at margins 10--14 x 7--15 /um, at midleaf 9--19 x 7--18
/um; trigones absent; oil bodies unknown.
Asexual reproduction by cauducous leaves absent; irregular discoid gemmae usually
copious, except in shaded sites, less than 1/5 the size of dorsal lobe. Sexual
condition dioicous. Androecia usually terminal on
branches, bracts imbricate, usually in 2--4(--5) pairs, spicate. Gynoecia
terminal on branches, bracts obliquely spreading, dorsal lobe ovate and
ventral lobe oblong. Perianth 1.7--1.9(--2.3) x 0.8--0.9
mm cylindric, sharply compressed, usually weakly 2-labiate, occasionally
deeply sinused.
Sporophyte capsule
ovoid-cylindric. Spores granulate, greenish brown, 1--3 celled, 1-celled 25--32
/um, 2--3-celled 35--45 /um. Trunks or
branches of trees of the evergreen components of both coastal swamp and
evergreen hammock forests; low elevations; Ala., Fla., Ga., La., Miss., N.C.,
S.C., Va.; West Indies Radula australis appears to be generally restricted to the Atlantic Coastal
Plain in the eastern United States from Louisiana to Virginia. 10. Radula prolifera Arnell, Ark.
Bot. 13(2): 12. 1913 Plants pale yellow green
at apex, mature portions often dull yellow, ca. 8--11.5 x 1.3--1.5 mm;
prostrate to ascending; terricolous; growing singly
among other bryophytes. Stem 112--124 /um in diameter, cortex
and medulla 7--8 cells in width, without a differentiated cortex; regularly
pinnately branched, not plumose; with microphyllous branches. Leaves
persistent; not undulate, distant, slightly falcate; dorsal lobe ovate, adaxially concave,
0.7--0.9 x 0.8--0.9 mm; base not auriculate; lobule (ventral lobe) united for
0.65--0.75 the length along stem from the base of the keel to the opposite
margin of the lobule, slightly convex, appressed to dorsal lobe, not undulate,
rhizoids sporadic, subquadrate to ovate, 0.3--0.4 x 0.3--0.4 mm, not
overlapping and hiding stem, apex obtuse with a bluntly angular to rounded
tip, base not auriculate. Leaf cells at margins 9--16 x 10--14 /um, at midleaf 9--25 x 9--24
/um; trigones conspicuous; oil bodies unknown. Asexual
reproduction by cauducous leaves absent; gemmae
absent. Sexual condition autoicous.
Androecia terminal on
stems, bracts imbricate, usually in 2--4 pairs, spicate. Gynoecia
terminal on lateral branches, bracts dorsal lobe ovate and ventral lobe
quadrate. Perianth unknown. Sporophyte unknown. Spores
unknown. Damp hummocks and
humus in the tundra, soil between the rocks of talus slopes; low to moderate
elevations; N.W.T., Yukon; Alaska; Asia. Radula prolifera is the only member of Radula
that has a solely Arctic distribution. 11. Radula brunnea Stephani, Spec.
Hep. 4: 232. 1910 Plants dark brown to
olive-green, dried plants red to blackish-brown, ca. (10--)20--65
x 1.7--2.8 mm; prostrate; epicortic, epilithic, or terricolous; growing in mats among other bryophytes. Stem
200--300 /um in diameter, cortex and medulla 8--10 cells in width, with a
differentiated cortex; irregularly pinnately branched, not plumose; with microphyllous
branches. Leaves persistent; not undulate,
imbricate, falcate; dorsal
lobe ovate, adaxially concave, 1.0--1.7 x 0.7--1.2 mm; base auriculate,
2--lobed or toothed; lobule (ventral
lobe) united for 0.25--0.33 the length along
stem from the base of the keel to the opposite margin of the lobule, slightly convex,
appressed to dorsal lobe, not undulate, rhizoids sporadic, subobovate, 0.6--0.7 x 0.5--0.7 mm, overlapping and
hiding stem, apex rounded, base auriculate and 2--lobed or toothed. Leaf cells at margins
7.5--12.5 x 10--18.5 /um, at midleaf 15--25 x 17.5--32.5 /um; trigones
conspicuous; oil bodies conspicuous, one per cell. Asexual
reproduction by cauducous leaves absent; gemmae
absent. Sexual condition dioicous.
Androecia terminal on
stems, bracts imbricate, usually in 5--6 pairs, spicate. Gynoecia
terminal on lateral branches, bracts dorsal lobe ovate and ventral lobe subovate. Perianth cylindric to obovate
2.6--2.8(--3) x 1.4--2 mm. Sporophyte ovoid-cylindric. Spores
minutely puntacte, deep brown, unicellular,
variable in size. On rock or humus
on cliff faces in both sheltered and exposed sites in North America, while in
Japan it is not only reported to occur on rocks and occasionally humus, but
the bark of trees as well; high elevations; Oreg.; Asia. Radula brunnea is known only from the cliffs of Saddle Mountain in
Oregon, and as a species has a disjunct distribution with East Asian
conspecifics occurring in Japan. 12. Radula obtusiloba Stephani, Bull. Herb. Boisser 5:
105. 1897 Plants yellow green,
mature portions often with a brownish cast, ca. (8--)12.2--21(--25) x 1.3--1.8(--2) mm; prostrate; epixylic, epilithic, or terricolous; growing in mats or singly among other bryophytes. Stem
117--154 /um in diameter, cortex and medulla 8--11 cells in width, without a
differentiated cortex; regularly pinnately branched, plumose; without
microphyllous branches. Leaves persistent; not undulate,
contiguous to slightly imbricate, slightly falcate; dorsal lobe ovate to obovate, plane,
0.6--0.8 x 0.5--0.6 mm; base very weakly auriculate; lobule (ventral lobe) united for 0.65--0.75 the length along stem from the base
of the keel to the opposite margin of the lobule, slightly convex,
appressed to dorsal lobe, not undulate, rhizoids sporadic, subquadrate,
0.5--0.5 x 0.3--0.4 mm, not overlapping and hiding stem, apex obtuse with a
bluntly angular to rounded tip, base slightly auriculate. Leaf cells at margins 7--9 x
9--10 /um, at midleaf 10--19 x 10--18 /um; trigones small; oil bodies
unknown. Asexual reproduction by cauducous
leaves absent; gemmae absent. Sexual condition dioicous. Androecia
terminal on short lateral branches, imbricate, usually in 4--8 pairs,
spicate. Gynoecia terminal, bracts dorsal lobe ovate and ventral lobe
subquadrate. Perianth 3.0 x 0.9 mm cylindric, sharply compressed, truncate,
irregularly repand.
Sporophyte unknown. Spores
unknown. Subspecies 2 (1
in the flora) 12a. Radula obtusiloba subsp. polyclada (A.
Evans) S. Hattori, J. Hattori Bot. Lab. 29: 275. 1966 E Radula polyclada A. Evans, Bull. Torrey Bot. Club, 41: 607. 1915 Stem primary branches
arising from nearly all stem leaves of the main stem. Rhizoids
often absent, or when present, extremely sporadic. Damp and shaded
rocks of cliff faces near Oceanside areas; low elevations; B.C., Alaska,
Wash. Radula obtusiloba subsp. polyclada is endemic to the coastline regions of the
Pacific North. The subsp. obtusifolia can
easily be distinguished from Radula obtusiloba subsp. polyclada in that the former
has much fewer branches arising from the stem leaves. 13. Radula bolanderi Gottsche ex Stephani, Hedwigia 23: 145. 1884 E Plants dull green or
yellow green, ca. (5.1--)11.0--19.8 x 0.9--1.1 mm;
prostrate; epicortic or epilithic; growing in mats or singly among other bryophytes. Stem
89--107 /um in diameter, cortex and medulla 6--8 cells in width, without a
differentiated cortex; regularly pinnately branched, not plumose; without
microphyllous branches. Leaves persistent; not undulate,
contiguous to imbricate, not falcate; dorsal lobe ovate to obovate, adaxially
concave to plane, 0.5--0.8 x (0.3--)0.4--0.6 mm; base slightly to moderately
auriculate; lobule (ventral lobe) united for about
0.5 the length along stem from the base of the keel to the opposite margin of
the lobule, slightly convex,
erect to suberect, not undulate, generally lacking rhizoids, subquadrate,
0.3--0.5 x 0.2--0.3 mm, not overlapping and hiding stem, apex obtuse with a
bluntly angular tip, base auriculate. Leaf cells at margins 6--12 x 5--10 /um, at midleaf 8--20 x 8--16 /um;
trigones small and inconspicuous, sometimes absent; oil bodies unknown. Asexual
reproduction by cauducous leaves absent; gemmae
absent. Sexual condition dioicous.
Androecia terminal on main
stem branches, bracts imbricate, usually in 2--35 pairs, spicate. Gynoecia
terminal on stem, bracts dorsal lobe ovate and ventral lobe subquadrate, both
lobes rounded at apex. Perianth 1--2.2 x 0.7--1.2 mm obovoid to obconic, shallowly 2-labiate, slightly sinuate occasionally deeply sinused. Sporophyte capsule oblong to
ellipsoid. Spores minutely
papillate, pale yellow brown, unicellular, (44--)46--60(--62)
/um. Humid shaded
evergreen forests on moist rocks and the bark of trees, coastal redwood and
Sitka spruce forest types; low to moderate elevations; B.C.: Alaska, Calif., Oreg., Wash. Radula bolanderi appears to be restricted to the western coastline of North
America. 14. Radula tenax Lindberg, Acta Soc. Sci. Fenn. 10: 492. 1875 E Plants dull green
usually with a bronze to brownish cast, ca. (8.5--)38--52(--60) x 0.8--2.1
mm; prostrate with stem tips arching away from substrate; epicortic or epilithic; growing in mats
or singly among other bryophytes. Stem translucent yellow-brown,
71--188 /um in diameter, cortex and medulla 8--10 cells in width, with a
differentiated cortex; regularly pinnate branched, not plumose; without
microphyllous branches. Leaves persistent; not undulate,
distant to contiguous, not to slightly falcate; dorsal lobe ovate to suborbicular,
adaxially concave, 0.6--1.0 x 0.4--0.7 mm; base slightly auriculate; lobule
(ventral lobe) united for
0.65--0.75 the length along stem from the base of the keel to the opposite
margin of the lobule, slightly convex,
erect to suberect, not undulate, rhizoids absent or very scarce, subquadrate,
0.2--0.3 x 0.2--0.3 mm, not overlapping and hiding stem, apex obtuse, usually
with bluntly right angular tip, base strongly auriculate. Leaf cells at margins 11--14
x 10--15 /um, at midleaf 10--21 x 10--20 /um; trigones small to conspicuous
and sometimes bulging; oil bodies 1 per cell.
Asexual reproduction by cauducous leaves absent; gemmae absent. Sexual
condition dioicous. Androecia terminal or intercalary on
primary branches, bracts imbricate, usually in 3--8 pairs, spicate. Gynoecia
terminal on stem or lateral branches, bracts widely spreading, dorsal lobe
ovate and ventral lobe quadrate. Perianth unknown. Sporophyte
unknown. Spores unknown. Rocks (calcareous
or acidic) and trees in humid forested areas, restricted to the Appalachian
mountain region of North America; low to moderate elevations; Conn., D.C.,
Ga., Ky., Maine, Md., Mass., N.H., N.Y., N.C., R.I., S.C., Tenn., Va., Vt.,
W.Va. Frye and Clark
(1946) report an occurrence of Radula tenax from B.C., though they qualify that in all
likelihood the identification is in error.
We treat this record as erroneous.
15. Radula auriculata
Stephani, Bull. Herb. Boissier
5: 105. 1897 Plants green with a
purple to brownish cast, ca. (35--)55--74 x 1.9--3.2
mm; prostrate; epilithic epicortic, or terricolous; growing in mats
or singly among other bryophytes. Stem pale to dark-brown, 184--319 /um
in diameter, cortex and medulla 10--12 cells in width, with a differentiated
cortex; regularly pinnate branched, not plumose; without microphyllous
branches. Leaves persistent; not undulate, distant to contiguous, not to slightly
falcate; dorsal lobe ovate, adaxially concave, (0.4--)0.8--1.3 x
(0.3--)0.7--1.3 mm; base moderately auriculate; lobule (ventral lobe) united for 0.65--0.75 the length along stem from the base
of the keel to the opposite margin of the lobule, slightly convex,
erect to suberect, not undulate, rhizoids absent, ovate-subquadrate, 0.3--0.7
x 0.3--0.7 mm, not overlapping and hiding stem, apex obtuse to acute with a
bluntly angular to rounded tip, base strongly auriculate. Leaf cells at margins 8--10
x 10--16 /um, at midleaf 10--22 x 9--22 /um; trigones small to quite
conspicuous, sometimes bulging; oil bodies unknown. Asexual
reproduction by cauducous leaves absent; gemmae
absent. Sexual condition dioicous.
Androecia terminal on short
lateral branches, bracts imbricate, usually in 3--6 pairs, spicate. Gynoecia
terminal, bracts widely spreading, dorsal lobe ovate and ventral lobe
quadrate. Perianth 1.4 x 1 mm, campanulate, repand. Sporophyte unknown. Spores
unknown. Humid shaded
areas on damp rocks, soil, humus, or the bark of trees (specifically Thuja plicata), places adjacent to streams,
lakes, and ocean side areas; low to moderate elevations; B.C., Alaska; Asia;
Indian Ocean Islands. Radula auriculata has a broad
distribution, being found in areas along the Pacific North and Southeast
Asia. The North American populations are in all respects identical to the
Asian populations (sensu K. Yamada 1979) excepting that populations of R. auriculata from North America are
more robust (35--)55--74 mm
in length than that of R. auriculata sensu K. Yamada,
which are only
(20--)30--40(--50) mm in length. As several of the
North America taxa within Radula
exhibit endemism, and there are subspecies within Radula with similar distributions, namely, R. obtusiloba ssp. obtusiloba and R. obtusiloba
ssp. polyclada, it strongly suggests that there may
be some significant genetic divergence between the North American and Asian
populations of R. auriculata. |
