A New Hymenophyllum Species in the Appalachians Represented by Independent Gametophyte Colonies

10 Pages·1991·13.7 MB·English

by  Catherine A Raine

*l*SSOORf
^TAHIC
R wa
Wfl
2
American
Fern Journal 81 109-118
(4): (1991) r)
^RDEN
UBRAHY
A
New
Hymenophyllum
Species in the Appalachians
Represented by
Independent
Gametophyte
Colonies
Catherine
A. Raine
Department
and
of Cell Structural Biology, University of Manchester, Manchester Ml 9PL
3
England
Donald
Farrar
R.
Department
of Botany, Iowa State University, Ames, Iowa 50011
Elizabeth
Sheffield
Department and
of Cell Structural Biology, University of Manchester, Manchester Ml3 9PL
England
known
;ametophyte
populations 1967L Thev
fFarrar, are
from
sporophytes of the species, by vegetative reproduction, includine
the
emmae
difficulty
Hymenophyll
southern Appalachian Mountains one by Mary She
Taylor. described
is the
plants as growing from one Hymenophyllum
'*not far of the stations for
The
tunbrigense." widespread occurrence independent Hymenophyllum
of
gametophytes in North and South Carolina w^as first reported by Farrar fl9671.
hat time, presumed the gametophytes 1-6) the same
[Figs.
Hymenophyllum
sporophyte
tunbrigense
(L.)
J
Carolina," Subsequent
Dublications
either sudi
remained uncommitted
(Farrar, 1985] or regarding [Wagner
their identity
et
al.,
1970]. However, the [Wagner and
rarity aL, 1970] relative
et sterility [Farrar,
1971) of H. tunbrigense sporophytes in the Appalachians, has always been
difficult to reconcile w^ith the frequent occurrence of independent
gametophytes.
Furthermore, Taylor described the gametophytes in her
those
W
There
are several problems in determining whether these gametophytes are H.
Hymenophyllum
tunbrigense Most
or not. studies oi gametoph;y'tes (Atkinson,
1960; Goebel, 1888; 1905; Holloway, 1930; Stokey, 1940; 1948; Stone, 1965),
have
concentrated on development rather than on distinguishing features of the
mature Few
prothalli. studies have specifically described characters of H,
we
tunbrigense gametophytes, and those that have been able to find included no
&
helpful figures Janczewski & Rostafinski, 1875; Richards Evans, 1972).
(e.g.
K
Also, Farrar (1971) was unable to grow tunbrigense gametoph5rtes in culture,
and
gametophyte form and
therefore did not obtain experimental data regarding
growth would have been
requirements and responses that useful in this study.
The Hymenophyllum
second
discovery of a single juvenile sporophyte of a
species in the United (Wagner 1970) ftirther calls into question the
States et
al.,
NUMBER
VOLUME
AMERICAN FERN JOURNAL: 81 4 (1991)
110
independent
Figs. i-8. Hymenophyllum in North and South Carolina. Fig. i. Typical site of
Pickens
Hymenophyllum gainetophytes and H, tunbrigense sporophytes along the Eastatoe River in
Hymenophyllum gametophytes rock crevices
Typical habitat (arrowhead) of in
Co., S.C. Fig.
2.
along fast-flowing streams. Figs. 4. Close-up of Hymenophyllum gametophjie population in Fig.
3,
Gametophj-t
Fig.
2. 5
proliferations on older part of thallus and gemmae near the apices (6X]. Figs. 8. Juvenile
7,
spore phyte ol Hymenophyllum subgenus Leptocionium collected by Mary S. Taylor in Pickens Co..
subgenus.
S.C in 1936 (U.S. no. 1731687) [5X. 15X). Note stellate hairs characteristic of the
NEW HYMENOPHYLLUM
RAINE ET 111
AL.:
Fig. Sites of live collections of the
9.
Hymenopbyllum
independent Appalachian
=
Macon
gametophytes used study.
in this 1
= Macon
Knob Dry
Co. Piney Creek; 2 Co.
=
Cullasaja River; 3 Jackson Co.
Falls,
Chattooga River Norton Mill Branch;
at
=
4 Jackson Co. Bonas Defeat, East Fork
=
Tuckasegee River; 5 Transylvania Co.
many =
Thompson
6 Transyl-
River, sites;
vania Co. Drift Falls, Horsepasture River;
=
Schoolhouse
7 Transylvania Co. Falls,
=
Greenland Creek; 8 Pickens Co. Eastatoe
many
River,
sites.
A
found
sporophyte
independent gametophytes. tiny (Figs.
identity of the 7. 8)
and been
hirsutum has
by Mary Taylor in 1936 was tentatively identified as H.
included as such in subsequent literature (e.g. Proctor, 1985; Lellinger, 1987).
However, on the basis of laminar hairs, it keys to any one of three species
its
mhami, and most H.
closely to
H.
(Morton, 1947): H. trichophyllum,
any of these
The not precisely identical to
pulchellum. structure of its hairs is
and from H. hirsutum.
auite distinct
is
number papers maintain
of
are
worK
recent
Stone,
Hymenophyllum Stokey, 1948;
context 1965J,
in this (e.g.
Techniq
gametophytic characters.
documented taxonomically useful
have
em
(SEM)
(Sheffield
was
when morphology Our aim in this study to
even not.
genetic differences is
Hymenophyllum
Appalachian species of
establish the identity of the
morphological and electrophoretic characters.
gametophyte using
Methods
and
Materials
August
were during
Hymenophyllum gametophytes collected
It
sporophytes
H. tunbrigense
from North and South Carolina (Fig. 9).
in
s
and
Gametophytes
South Carolina.
same time from in
sites
the
at
i
Maentwrog, North Wales in
were collected at
tunbrigense
H.
)f
H.
sporophytic material of
Mickel kindly sent living
Dr. T.
).
J.
independent
with
um which was compared electiophoretically
gametophyte
material.
room
cold
in the
Specimens were maintained either
um
Permanent
(Bold. 1957).
solution
mineral nutrient
moun "
made by
were
samples
ametophyte
around covershp edges
varnish
gum and by painting clear nail
Faure^s chloral
to prevent desiccation.
VOLUME
AMERICAN FERN JOURNAL:
112
that
SEM
they were kept no more than two days in sealed petri dishes
cleaning, for
damp were remove
containing tissue paper. Just before use they blotted to
excess water.
made
Isozyme Electrophoresis.— Extractions were using either the
tris, tris-
maleate, or phosphate grinding buffers of Soltis et [1983). Their staining
al.
protocols and buffer systems 6 and or the morpholine (M) systems of
8,
&
Odrzykoski were used analyze aspartate Eimino transferase
Gottlieb (1984), to
phosphoglucomutase (PGM), malate
phosphoglucoisomerase
(AAT),
[PGI),
(MDH) (SKDH)
dehydrogenase shikimic dehydrogenase
isocitrate
, ,
dehydrogenase (IDH), peroxidase (PER), trios e phosphate isomerase (TPI), 6
phosphogluconate dehydrogenase {6PGD) and fluorescent esterase (FE).
Scanning Electron Microscopy.— The morphologies of Welsh H. tunbrigense
gametophytes and independent Hymenophyllum gametophytes from the
SEM
low
Appalachians were investigated using a Cambridge S200 fitted with a
&
temperature stage, using the methods of Sheffield Farrar (1988).
Results
Isozyme Not enzymes were
Electrophoresis.— the well resolved in
all all
among
specimens of independent gametophytes, but no variation was observed
From we American
nine samples from four sites. this conclude that all the North
independent gametophyte same With
collections represent the species. the
PGM
exception of one band in some specimens of H. tunbrigense, the
independent gametophytes shared no bands 19 with either H,
(of
total)
K
tunbrigense or pulchellum
(Fig. 10),
Many
Morphological Features.— gametophytic proved extremely
features
variable and of 54 characters initiallv investieated. onlv nine seemed to varv
m
meristem
width and position) to be used. was not possible to extensively investigate the
It
morphology and
of antheridia archegonia Appalachian gametophytes
in the
because they were very rare in our cultures. Table features that
1 lists
distinguish the independent Appalachian gametophytes from those of H.
tunbrigense.
gemmae
The
of the independent gametophytes of
are characteristic
Hymenophyllum
Leptocionium, subgenus
subg. the previously suggested for
gemma-
Taylor's sporophjle, as compared to those of subg. Mecodium, the other
producing subgenus of tropical America, In the basal on either side
latter, cells
of the attachment cell become conspicuously swollen and generally protrude
downward beyond No gemmae
the attachment cell similar growth occurs in of
NEW HYMENOPHYLLUM
RAINE ET 113
AL/.
;^>;«*T^t
X-
2 3 4 5 6 2 3 4 2 3 4
1 1
1
'^^.
•^ K -
c
b
MDH
compared with both Welsh H. tunbrigense
Appalachian Hymenophyllum gametophj-te (Lane 4)
and
MDH
United States (Lane b. banding patterns. Lane 1, H. tunbrigense sporophyte; Lane 2, H.
2).
Lane Independent gametophyte.
pulchellum sporophyte; Lane H. tunbrigense sporophyte; 4,
3,
6PGD Lanes
banding patterns. as in b.
c.
Hymenophyllum tunbrigense and the
Table Morphological characteristics of gametophytes of
i.
Hymenophyllum gametophyte.
Appalachian
independent
Hymenophyllum
Independent
Hymenophyllum
tunbrigense
Gemmae
present
Gemmae
absent
composed
Margin crenated,
composed predominantly
Margin
entire,
with concave
predominantly of cells
of straight-sided cells
outer walls
Archegonia and antheridia rare
common,
Archegonia and antheridia
same gametophyte
on
often present the
Sprawling growth habit
growth
Rosette habit
broad
Branches filamentous to
Branches always broad
abundant, arising at
Proliferations
always marginal
Proliferations few,
and
margins centrally
unpublished
Stone, 1965; Farrar,
1888;
(Goebel,
Leptocionium
subg. (Fig. 11)
gemmae
nor gemmifers
Neither
Hymenophyllaceae).
Hawaiian
on
observations
m
and have not been reported
tunbrigense
gametophytes of H.
were
present in
subgenus
Hymenophyllum, the third of
subgenus
other species of
this or
1875; Stone, 1965;
Qanczewski Rostafinski,
American Hy
Richards & Evans, 1972; Yoroi, 1972).
constant feature
branches, or proliferations,
regenerated
although
gametophytes,
independent
NUMBER
VOLUME
AMERICAN FERN JOURNAL: 81
114
f
mm
m m 0.5
0.05
Hymenophyllum
Gametophytes and gemmae of the independent Appalachian
Fig. 11.
gemmae (subgenus
gametophytes (subgenus Leptocionium] compared with of H. wrightii
Mature
Mecodium). Independent Appalachian Hymenophyllum gametophyte. a-c.
a-e.
gemmae
Gemma-producing Mature dehisced gemmae, Mature dehisced
gametophj^es. apex.
d. e. f.
of H. wrightii. Note protrusion of basal cells beyond attachment cell.
some marginal
had pronounced
crenations Occasionally of the
less (Fig. 12).
These have not been noted in other
cells are sclerified. features specijfically
species.
Archegonia were present in three cultures of Appalachian gametophytes [Fig.
be
but no antheridia were found. Farrar found antheridia to rare in
(1971)
13),
Archegonia were abundant on H. tunbrigense
field collected plants.
gametophytes and were often associated with antheridia (Fig. 15).
(Fig. 14)
form
Mature H. tunbrigense gametoph}i:es resembled the classic rosette
HoUoway
described by (1930) and Stokey (1940), rather than the sprawling
ribbon form of the independent gametophytes. The Appalachian gametophytes
with
form in part because they frequently produce branches
to attain rosette
fail
narrow bases that are easily detached (Fig. 16). These proliferations act as a
means from the
reproducing
further vegetative of the colony. Proliferations
been
which developed have not
center of the thallus, after a year in culture,
Hymenophyllum
noted in gametophytes in previous studies (Fig. 17).
NEW HYMENOPHYLLUM 115
RAINE ET
AL.:
"
^^^^P^^
Hymenophyllum. FiG. P™'^:"^
..-17. Gametophytes oi ^2. ^f
Figs. ^^^^^
- P^"^;,
Bar 100 ^.m. FiG_ 13.
pronounced crenations.
bearing less
margins and with a proliferation
-
pronounced curvature --P-^^^^f
Note
gametophyte.
independent
Archegonia of the °t^
tunbngense. Bar « 50 M-m. Fig i^-
H = Archegonia of H.
Bar 50 p.m. Fig. 14.
Iof Ltunbrisense
on an independent
ofTi^^^^ = Marginal proliferations
50 ^.m. FiG. .6.
idfa
development from
illustrating its
= Young proliferation
^m. central
^rTetophyte Bar 50 Fic. .7.
=
Bar 25
gametophyte. M-m.
the middle of the
Conclusions
and
Discussion
independent
the
indicate that
analyses
and morphological
Electrophoretic
Enzyme
cannot be H. tunbngense.
gametophytes
Hymenophyllum
Appalachian
VOLUME NUMBER
AMERICAN FERN JOURNAL:
81 4 (1991)
116
banding patterns of H.
dismiss
m
environments superimposed on the
from responses
the plants' to differing
number
morphological
gametophytes, of features reliably
innate variation of a
independent gametophytes from those of H. tunbrigense.
distinguish the
Hymenophyllum
On
independent
the basis of current evidence, the
gametophytes cannot be any named species. As with the
identified as
independent Appalachian Vittaria gametophytes [Farrar, 1990], they possibly
and
an ancient species long isolated in the eastern United States distinct
are
We
DroDOse
H.
Mary
Wa
from South Carolina 1938:
fTavlor,
Hymenophyllum tayloriae Farrar and Raine, sp. nov. (Figs. 4-6, lla-e, 12-13,
16-17.)
Plantae in statu gametophytico tantum existens; thalli ramosi ecostati tenues,
marginem
cellularum in unae compositi; rhizoidea ad
strato crassitie cellulae
gemmae
ramorum
limitatus; meristemata rotundata gemmipara; spathulatae,
5—8
2-4
cellulas longae, cellulas
latae.
Sporophyte Gametophyte
lacking. yellow-green, epipetric or occasionally
epiphytic on roots, perennial and clone-forming by vegetative reproduction.
Mature composed
plants of an irregularly branched, ribbon-like thallus one cell
in thickness. Growth indeterminate by marginal meristems rounded ends
the
at
of branches. Branches by meristems and by
arising division of terminal
proliferations from marginal and occasionally from medial of older
cells
cm
mm.
portions of the Branches 0.1-1.0 wide and up
thallus. to 1.0 long.
Margins
of the thallus often crenate by curvature of the cell walls. Marginal cells
occasionally sclerified. Rhizoids short, brown, emanating only from marginal
cells of the thallus. Aerial branches frequently terminating production of
in
mm
Gemmae
gemmae. composed 5-8
of spathulate plates of 0.1-0.2 long,
cells
and 2-4 way
cells long cells wide, each attached to the thallus by of an orbicular
gemmifer gemma
remains
cell that attached to the thallus the shed.
after
is
Archegonia on
clustered cushions along margins Antheridia
the of large
thalli.
on
Inallus margins.
Type: U.S.A.: South Carolina: Pickens Co., Eastatoe River below junction with Rocky Bottom
Creek, under rock outcrops along river, 22 June 1970, Forrar 1312b [holotype ISC; isotypes MICH,
MO.
NC, NY. UC,
US).
Representative Specimens: North by
U.S.A.: Carolina: Jackson Bonas moist ledge
Co., Defeat,
Aug
Anderson
waterfall 23 1951, 10593 (ISC); Chattooga River junction with Norton Mill Creek,
at
under rock ledges, 6 Aug 1966, Farrar 1121 (ISC, MICH, MO, NC, NY. UC. US); Wolf Creek Falls,
Wolfe Macon on Piney Knob Aug
Pittillo &- s.n. (ISC); Co., Falls Creek, in crevices east side of falls, 2
1966, Farrar 1111 (ISC, MICH, MO, xNC, NY, UC, US); Falls on Piney Knob Creek, in moss mats on
boulders in stream below falls, 2 Aug 1966, Farrar 1 1 12 (ISC, MICH, NY, UC. US); Dry Falls, under
Aug
cliffs on east side of falls, 23 1989, Farrar 89-8'23'l (ISC, US); Transylvania Co., Drift Falls on
Horsepasture River, in crevices in rock outcrops on west side of river below the 21 Aug 1989,
falls,
Farrar 89-5-21-7 (ISC. NY, US); Schoolhouse Falls, on soil and root masses under cliffs west of falls.
NEW
HYMENOPHYLLUM
RAINE ET
117
AL.:
20 Aug 1989, Farrar 89-8-20-8 (ISC, MICH, MO, NC, NY, UC, US); Thompson River Falls, under cliffs
below 26 July 1966, Farrar 1092 (ISC, MICH, NY, UC, US); South Carolina: Pickens Co.,
falls,
Eastatoe River, moist shaded rock in deep ravine, 19 April 1936, Taylor s.n. (US #1731687); Eastatoe
Aug MICH, MO. NC,
River, cliffs along river at lower end of gorge, 24 1989, Farrar 89-8-24-1 {ISC.
NY, UC, US] Eastatoe River, along river between upper narrows and Rocky Bottom Creek, with
cliffs
;
K
tunbrigense, 24 Aug 1989, Farrar 89-8-24-18 [ISC, MICH, NY, UC, US); Rocky Bottom Creek near
Aug
junction with Eastatoe River, on north-facing in narrow gorge, 24 1989, Farrar 89-8-24-22
cliffs
MO,
MICH, NC, NY. UC.
US).
(ISC,
Mrs
ametoDhvtes
of H,
The most
organically connected to the sporophyte. diagnostic character of the
sporophyte attached the margins and midrib but
the stalked hairs to
stellate
is
Such and placement
not the lamina of the hairs their are characteristic
to leaf.
of subg. Sphaerocionium, section Sphaerocionium, subsection Ciliata of
now
Morton Leptocionium considered be the appropriate
(1947, 1968). is to
name
subgenus.
for this
A
with
gametophytic character of H. tayloriae allies also subg.
it
The
unmodified
Leptocionium and thus with Mrs. Taylor's juvenile sporophyte.
basal cells of the gemmae of H. tayloriae are similar to those of other species of
Mecodium
Hymenophyllum which apparen
Mrs
H
with
sporophyte be probably conspecific
to
from independent gametophytes of Vittaria
H. tayloriae distinguished the
is
gemmae
appalachiana and Mickel by 2-dimensional spathulate (those
Farrar
its
attachment only marginal
appalachiana rhizoid to cells,
of V. are uniseriate),
and
more
than
gemmae
meristems, and do not produce spathulate
found moist
H. tavloriae in
is
overhan
streams
amon
found
Occasionally they are
masses.
Thp known from sorges oft
snficies
Falls is
South
North
and Macon, and Transylvania counties in
Jackson,
Hymenophyllaceae has been ascribed in part h
of the
iccess
and
ametonhvtes regenerate from a few green cells their
to
emma
the
loited to full
1
emmae
allows H.
from
Acknowledgments
Mickel
and
VOLUME NUMBER
AMERICAN FERN JOURNAL:
81 4 (1991)
118
independent gametophytes
technical assistance, and Dr. D. Pittillo for assistance in collecting
for
J.
North Carolina.
in
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