Acta
Botanica Neerlandica
the
On
11
216-224
(1962)
Delimitation
of
the
Genus
Gahnia
(Cyperaceae)
J.H. Kern
( Rijksherbarium,
the Hawaiian
Although
J\ew Zealand Lampocarya
and also agree in
though
Morelotia
by
Gaudich.
maintained
were
authors
most
and
the
extremely similar in habit
are
details, they
species
1962)
gahniaeformis
affinis Brongn.
numerous
related
closely
Leiden)
14 th,
{received February
distinct,
as
of the last
century.
To be
had only seen specimens of the Morelotia
sure, Kunth (1837)
species, Steudel (1855, p. 164) suspected the two to be but varietally
distinct,
and
Hooker
Gahnia arenaria
drew
351-352)
the distinct
referred
Boeckeler,
in Gahnia
did
and
the
who did
R.
J.
Some
On
&
not
twenty
Forst.
years ago
86)
in
the
Beni
length
New Zealand
for their
both
again
found
of the
R.
monographs
p.
of
species,
for
most
on
subsequent
Steud.
(Brongn.)
He
authors
opinion.
the genus Gahnia
were
exposition of the differentiating
negligible difference between the two
not
and in
Kiikenthal’s
opinion
differ from the Hawaiian
more
ciliate
gahniaeformis
Gahnia
which
and
Brown, classified them
gahniaeformis
he
the
accepted
found several
ones
Lampocarya
binomial
affinis
Heller.
(Gaudich.)
additional
the
except
glumes. Therefore
and
Recently St.John (1958) reestablished Lampocarya affinis
distinct
Kunth
Hooker,
clear
a
Morelotia
the synonymy
to
of
p.
out
165-169, f. 6) and Kükenthal (1943,
inflorescence,
specimens do
referred
binomial
(1874,
pointing
Steudel,
shared Hooker’s
two
only
genus
paler leaf-sheaths and slightly
authors
especially
Brown;
Unfortunately
but
Boeckeler’s
ignored
characters.
the
Boeckeler
different characters of their fruit.
published. Both Benl (1940,
p.
descriptions
recognize this
Boeckeler,
under
them
hand,
other
Lampocarya
to
G.
the
accurate
specifically
species
follow
not
f.
two
up
combined
(1867)
Hook.
as
a
clearly
Gahnia
constant
affinis
differences
with Gahnia
gahniaeformis overlooked by Boeckeler and others.
My attention was drawn to these species by a splendid collection
of Gahniae from the Hawaiian Islands
by
Dr.
O.
presented
to
the
Rijksherbarium
Degener.
I agree with St.
John that specific separation of the two is fully
justified. When nevertheless I revert to the subject it is because I am
convinced that the
removal the
For
better
a
of Gahnia
J. R.
as
&
species
were
misplaced
circumscription of this
understanding
given by
G.
of the
Kukenthal
Forster
(1776)
in Gahnia and
genus will become
following
(1943,
based
p.
the
Gahnia procera, which therefore is the type
216
59)
that
more
discussion
needs
genus
on
some
a
by their
satisfactory.
the
history
corrections.
single
species,
species by monotypy (Kern,
DELIMITATION
Robert
1957).
Brown
OF THE
(1810)
created
a
new
.
as
the second
only
was
species, L. aspera R. Br.,
new
hexandra R.
species, L.
transferred
tentatively
intermediate between Cladium
former
transversely
last
it.
considered the
on
Gahnia trifida
Lampocarya
Browne and Gahnia,
of the
seed,
Although
rugose.
in
century followed Brown, it
was
and that
newly discovered species
realized
soon
related species had
system closely
be
to
difficult
were
(1855) united Lampocarya and Gahnia, but
the
for
the
at
Gahnia
that
latter
by application
genera,
Steudel
classify.
to
time he created
same
Mor.,
the
seed
in different
placed
be
being
early part of the
authors of the
most
from
to
from the
differing
Gahnia proper the
type,
Labill.,
said
was
and
by its filaments elongated after anthesis,
by the smooth surface
of his
based
Br.,
to
be
must
,
,
.
which his
of
Lampocarya,
genus,
,
.
217
GENUS GAHNIA
genus Syziganthus
javanica
species certainly
belonging in Gahnia as circumscribed by himself. Besides, those species
which
to
Brown
had
wrongly
Gahnia. Boeckeler
the
reduction of
Bentham
(1878)
Von
Against
properly
entitle them
in Cladium
there
are
whereas in such
flower-bearing
Cladium there
do
discuss
to
von
exist
rank.
transferred
not
were
arrangement except for
same
he
that if
the
distinct
that when
out
species
sufficiently
groups
pointed
had united them.
(1875)
objected
two
He
amply the circumscription
Muller
the
two-flowered the lower flower is fertile and
are
of the flowers
F.
the
Gahnia.
procedure
generic
to
to
the first
was
Muller’s
placed,
had
(1874)
Syziganthus
of Cladium and Gahnia, after
in Cladium
placed
a
long
as
as
are
even
longer
in Gahnia the
spikelets
glumes
or
are
shorter
than the
upper
than
outer
outer
the
glumes
empty ones,
empty
three stamens, in Gahnia three to six. It
to
spikelets
flower is fertile and
the
are
ones;
the
in
emphasized
was
that in Cladium there is
with
“in
an
almost always a small glume either empty or
imperfect flower, which flower is lacking in Gahnia, although
the section
Gaudich.,
flower.”
Lampocarya,
there is
...
This assertion
of Gahnia
trifida,
glume with
a
investigated
by
under Cladium
but
which
me,
solely
a
small
is much weakened
species
there is
imperfect flower.”
I
on
which
empty glume above the
by Bentham’s description
“rarely
In the
a
species which
on
flower.
elongated after
not
account
of several
important characters showing their close relationship
representatives of the latter, Bentham
tion of the
two
unanimously
Yet
it
Gahnia
Benl
the
the
followed
appears
monographs
and
genera.
(1940,
leaves,
the
(both
in
this
the
very
gave
some
of
Bentham’s
a
with
much better
disputed
more
the other
circumscrip-
cases
he has been
and
Küken thal’s
day.
discussions
drawing
156-157) pointed
p.
the
number
to
from
that
Apart from
additional
R. Brown had described
of the filaments
account
belong in Gahnia
small
spikelets of that species
always found this vestigial
in Gahnia those
By including
anthesis,
in
second
including the Sandwich Island Morelotia,
sometimes
a
in
Beni’s
dividing
line
circumscription)
out
between Cladium
is
far
that the characters
from
easy.
taken from
position of the fertile flower in two-flowered spikelets,
of
the relative
stamens,
length of the flower-bearing
glumes, and the attachment of the ripe fruits to the persistent filaments,
218
H.
J.
Fig.
I.
and
glume embracing
Machaerina gahniaeformis
mechanism,
x
6;
Machaerina affinis
5:
sterile
sterile
X
(Gaudich.)
flower,
flower,
(Brongn.)
Kern
10;
KERN
X
—
x
40;
8:
10-11:
6;
Kern—
3:
6-7:
longitudinal
longitudinal
diagrams
1: spikelet,
of
section
spikelet.
6; 2;
x
deflorate flower,
x
sections
of
fruit,
6;
of
x
rhachilla
4:
fruit,
10;
9:
fixing
x
10.
fruit,
DELIMITATION
let
down in many
one
is
character
less
or
more
(1943,
afforded
linking
that
the
and G.
being
2.
a
will
certain
as
it
fruits.
Also
be based
cannot
be
always
in Cladium
Kukenthal
any constant
on
“borderline-species”
some
Bentham, Beni,
to
of Gahnia
extent
in Gahnia are
under
species
two
trigonous
(l.c.,
and Kukenthal
found in
are
Gahnia
affinis
points
and G.
affinis
contradistinction
always
the fact
to
gahniaeformis
all other
to
1943, p. 57),
rightly described
(Kukenthal,
terete
discussion, however,
are
86).
p.
Kukenthal himself
leaves in Gahnia
in
arbitrary
there
properties according
to
stems
those of the
as
the
differentiating
style-base
gahniaeformis?
The
1.
in
even
the best
enlarged
two.
Which of the
characteristic
opinion
held the view that the discrimination between Cladium
and
up
off
set
and Gahnia will remain
character,
his
by the strongly
distinctly
57)
p.
In
cases.
219
GENUS GAHNIA
THE
OF
Gahniae,
that the
are
of the
margins
revolute, this
strongly
which have
involute
leaf-
margins.
3.
The
the
flower-bearing glumes in Gahnia
surrounding
empty
affinis and G. gahniaeformis they
and very
ovate-lanceolate,
in several other
well-developed
4.
the
More
glumes
descriptions
they
5.
I
not
always
perfect
have
dissected
and
understand
already
are
not
(Fig.
whereas
to
used
trifida.
the
to
as
a
are
an
a
subtending bract
spikelet
flower
imperfect
character
absolutely
above
the
the
discriminating
spikelets of Gahnia microstachya Benth.
even
to
be
uppermost
in
instructive
more
this
three-flowered,
imperfect
one
imperfect
are
The transverse
that in Gahnia the
(with vestigial pistil), the
male
they
the fact
I found them
topmost
imbricate
them.
of
absence,
9-11)
11,
functionally
the
by
as
the fertile flower, and that therefore
and Gahnia. The
vestigial). However,
in
G.
ones,
remarked that
glumes
defined
rightly
with respect
misled
pointed
be
cannot
fertile,
Gahnia,
be
it should
empty
why they should be called
spikelets
have
may
terminated
than those of G.
flower
Here
descriptions both by Beni and Kukenthal.
between Cladium
I
outer
and
always
are
respectively
one
longer than the
than
in
is that in Gahnia
gahniaeformis and in G. affinis
exactly distichous (Fig. I, 11), whereas in the generic
of the lateral
presence,
but
either.
and/or prophyll
is
rule shorter
a
members of the genus the conchiform
cannot
in the specific
position
acute.
as
conchiform,
important
are
all round. I
are
are
obtuse,
ovate,
ones,
(both
flowers
rule in Cladium.
next
and
pistil
exceptional
are
They
bisexual
one
stamens
respect
the lowest
are
in
lacking
never
Gahnia
(1940,
was
p.
gahniaeformis and G. affinis (Fig. I, 5). Benl’s assertion
169) corroborated by Kukenthal (1943, p. 87) that Boeckeler
wrong
inaccurate
bifloris,
sione
in
ascribing
two-flowered
observation.
utroque
sterili”
Kukenthal,
flore
leaves
who
Boeckeler’s
hermaphrodite,
nothing
holds
to
be
the view
spikelets
G.
to
description
sed altero
desired
(Fig.
affinis is due
(1874)
(supremo)
I,
to
“spiculis
compres-
10-11).
that the so-called
spikelets
are
in
220
Fig.
X
8;
of
X
J.
2.
10.
Gahnia aspera
Gahnia beecheyi
spikelet,
spikelet.
10;
14:
(Labill.)
X
10.
Gahnia
nut
F.v.M.
Spreng.
Mann.
Beni.
x
Gahnia microstachya
hystrix J.
seen
16:
globosa (Mann)
perigonial scales,
var.
4-7:
from
M. Black.
above,
spikelet,
X
6;
H. KERN
Benth.
12: nut,
X
10;
17:
nut,
15:
X
9-11:
X
1-3:
20.
flowers,
10;
13:
X
18;
trifida
20;
19:
Labill.
diagram
id., longitudinal section,
deflorate flower,
6;
perigonial scales,
Gahnia
x
6.
Gahnia
id., longitudinal section,
filum
X
6.
OF
DELIMITATION
sympodia and
fact
by
even
pseudo-spikelet,
I
Although
misleading.
the
by
if
However,
not
its
another
flower,
male and
male
a
ordinate
In my
also
a
secondary
11,
are
found,
of the
but
flower is
19). With
always
mistook
the
flower and
concluded
52)
var.
globosa
number of
is
affinis
of the
Boeckeler’s
affinis
(1874,
ima basi
basi
partly
a
surprising
species
are
as
of
the
is
tribus
and
I
and bristles
backs
now
also
the fertile
Kukenthal
worse
the
Gahnia
four
to
description
In
lacunosa
the
G.
other
six.
of
the
in
nut
Gahnia
abbreviato-ovata
“caryopsi(s)
prominentibus,
and
gahniaeformis
imperfect flower.
often
(1943,
in Gahnia
perianth
flower.
a
in
follows:
sulcata
remnants
affixed,
scales
which
mistaking
both
accurate
runs
and in
seen
I,
fruits
7), just
compared
ripe
(Fig.
decurrent
in
like
that Boeckeler’s
the
the
be
must
section
as
none
in Gahnia
very young
longitudinal
be
that
in which
corky style-base
have
it
the
as
imperfect flower which it embraces,
in
in
genus
subpyramidali
large style-base
(Fig.
stamens
matters
remnants
even
bristles
hypogynous
them
the
to
glumes
lacunulosa
rufa, styli
coronata”
pallidiore
(italics
mine).
It is
that
the
stamens
attenuata, costis
crassa
Mann similar
to
interpreted
the
appressed
tightly
gahniaeformis,
reverse
very
353)
p.
to
(Mann)
better be treated
may
Unfortunately Hillebrand
more.
To make
for the
three,
always
representatives
7.
(1888)
Gahnia
the
to
The
aspera
6.
once
scale.
sub-
monograph
globosa
var.
beecheyi
gradual transitions
clearly belongs
so
perigonial
a
never
flower
in Kvikenthal’s
organs
the base of which
in
of
typical Gahnia aspera mainly in having
glume-like
here with
glume
so-
trace
a
there is
imperfect
an
Spreng.
aspera
from
Hillebrand
is demonstrated here
placed
the
exceptions
primary flower functionally
right. The homology of hypogynous
was
flower.
therefore does
seemingly
few
a
terminated
one-flowered without
In the related Gahnia
to
and
fertile, whereas in Cladium
Gahnia
shaped,
1-3).
perianth
think he
of
short
is
‘upper’
the
by
one
very
imperfect
11,
either
are
differs
11, 4-7).
(Fig.
says
is
sometimes
are
axis
flowers.
one.
correction.
irregularly
(Fig.
to
axis
opinion another misinterpretation
nut
p.
terms
the
applies
of the
position
which endemic of the Hawaiian Islands
few
for
nevertheless
these
this,
in
and almost
perfect
subspecies
a
relative
the
one
flower
the
to
needs
Beni
as
the
the
two-flowered with the
or
primary
replace “spikelet” consistently
‘Fachel’,
(Fig.
in Gahnia
spikelets
to
as
221
GAHNIA
or
secondary
mother-axis,
one
GENUS
primary flower-bearing
the
subordinate
lower than the fertile
called
to
the
flower,
this
overtop
‘lower’
rhipidia
‘lower’
far
followed him
have
In
so
rhipidium,
and
‘upper’
terms
goes
THE
of
nut
is
cited above
crowned
ever
gahniaeformis
can
easily be
(Fig. I, 3); in ripe
I, 6).
on
the
Gahnia
In
seen
fruits it is
suitable sections
little-pronounced
affinis
(Fig.
I,
to
8).
in the
affinis.
ovary
only visible in
the
style-base is
angles
of
When
Kukenthal
young
fruits,
fruits of Gahnia gahniaeformis with the
G.
realized
by the much thickened
misplaced in Gahnia (Fig. I, 9). The equally
description only applies
young
nuts
of the authors
the
he
nut
must
description
222
J.
8.
Fruit
dispersal
nismus”)
and
restricted
to
the
KERN
of
means
fixing mechanism (“Klemmecha-
mechanism
braiding
Gahnia,
genus
that in Gahnia
The fact
species.
by
H.
but
pronounced (Fig. I, 4),
species
Lampocarya),
G.
Benl
allied.
the various
means
worked
dispersal
reflect
to
From
two
out
the
in Cladium
on
distichous
glumes,
fused
to
the
nut
the
the
If
Nees.
need
of
1937, which
Benl,
clear
in
the natural
Gahnia, but
intended
of the
place
rather be
must
the revolute
trigonous stems,
of
not
were
Kiiken-
the types of
1950).
that
be
on
the
leaves,
imperfect secondary
an
be
not
between
distinguish
Gahnia, already criticized
flower,
greatly thickened style-base which remains
corky style-base should
I
have
the
far
so
latter
Cladium
to
C.
be
of the
decisive,
glumes and the
the
not
reasons
occurrence
the rhachilla
and
transfer
to
In the
in
I
to
have
which in
affinity
M.
seen
my
As
are
dorsoven-
not
so
in habit
nut
is
pronouncedly
to
species
in Schoenus
as
case
any
as
no
less different,
more or
and is in
as
such
preferable
as
it
is
genus
and
my
and
I
attempts
taxonomical
present
Gahnia,
especially
inter-
subfamily Rhynchosporoideae
Kukenthal’s
will
purpose
leave
the eventual
(1938)
problems
clear
to
to
were
up
the
the delimitation of
splitting
up
of Machae-
research.
only
two
opinion
is
of which I still
Black
to
morphological
of the
genera,
future
though
justified
some
affinis
the ultimate internode of
denied. However,
intricate.
very
successful.
the related
rina,
more
are
Lampocarya
Gahnia.
elucidate the difficult
very
and
there
desirable. Their leaves
is found and the
of the
type
are
circumscription
Unfortunately
gahniaeformis
be
referred
group often
relationships
not
less
cannot
by
The other
elongated
Machaerina seems
retention
to
is
and
adopted
and its few immediate allies.
certain resemblance
a
falcatus R. Br.
corky style-base
be
Gahnia
restricted
reason
probably three-ranked,
I, 2)
(Fig.
in Schoenus L.,
to
Koyama
of
sense
(1956)
good
of Morelotia
Machaerina appears
and
taken in its wide
Machaerina Vahl.
to
why transfer
trally flattened
Schoenus
With
characters
generic
be
must
jamaicense Crantz
he referred
species
the
opposed
name
Kiikenthal and others.
J.
to
Mor.,
fixing mechanism in the fruits.
Cladium,
to
tristis
dispersal
Especially the distichy
proper.
of the
be
presence
and
the first
(see
cannot
of the
account
stamens,
persistence
of
paper
it will
foregoing
under discussion
of fruit
sect.
name:
javanica
being mainly based
as
taxonomical affinities
species
the three
in Beni’s
in
G.
and
Forst.,
G.
as
Kiiken-
why
reason
(correct
such
species
was
fruit dispersal
thal’s subdivision of the genus
the
was
Inclusae
type
same
who
(1937),
of
section
schoenoides G.
species with the
However,
closely
G.
Spreng.,
aspera
in his
unrelated
with
along
not
Cladium
gahniaeformis and G. affinis the fixing
thal
these
found in several
also
mechanism is well
placed
is
(“Flechtmechanismus”)
is
(Fig.
11,
rather poor
specimens
certainly misplaced
do
not
12-15),
know.
in
I
which
am
in
of another
Gahnia,
alluding
peculiar
but
to
species
the actual
Gahnia
dwarf
species
hystrix
from
DELIMITATION
and
there is
Gahnia
the
GENUS
glumes
is
all the
perfect.
but
spikelets,
I
S.
it
T.
is
Blake
whether Gahnia
wonder
Kiik.
(1908) and made the type of
since has
similar
The
It
89)
is
difficult
it
and
species
Because
Gahnia.
in
spikelet, it is difficult
and
the
narrow
(Fig.
11,
16-18).
species
two
Machaerina
Morelotia
28;
in this
be
Machaerina
and F.
(1940,
trifida
(Fig.
are
and
I
to
8),
as
with
Cladium and
to
glumes
two
to
each
distichously arranged,
is
style-base
must
11,
to
1950,
differences
essential
only
Brown
232;
p.
of
met
Muller
von
respectively
are
small
case
available
affinis
affinis Brongn.
in
Phan.
166.
(1834)
assignment
the difficulties
peculiar
opinion that
very
refer Schoenus
filum Labill.
defer my conclusion
until
me.
to
Kern,
(Gaudich.)
in
Freyc.,
Voy.
comb,
Atl.
Bot.,
nov.—
(1826)
416.
(1829)
text
to
with Bentham’s
agree
to
Gaudich.
generic
Gahnia
the
them
gahniaeformis
gahniaeformis
by
Tetrariopsis, which
flowering specimen
spikelet is apparently
Benl
why
there
congeneric
not
will
materials
the
Baumea,
with
rather
lam inclined
are
Tetraria
to
Tetraria
described in Schoenus, R.
to
shown
filum
with
from
were
a
points
decide whether they
but also
Machaerina,
had
had referred
to
nut
only
are
two-
some
flowers
related
genus,
of the
to
was
conspecific
Gahnia
new
seen
as
understand
(1878)
a
already
M.
Boeckeler
to
as
Bentham
the latter
opinion
v.
Cladium,
to
regarded
already
F.
be
in
as
hystrix.
species. Originally it
transferred it
t.
arranged
one,
short, and the
whether both
structure
Gahnia
of
diversity
great
with in this
more
in
that
to
very
segregated
was
I have
in which the
filum (Labill.)
Gahnia.
latter
fallen into oblivion.
Tetrariopsis,
Gahnia
to
perfect
observed
hystrix could
Clarke
of this
The
are
(1943)
clear
not
(Nees)
the
the
to
internodes of the rhachilla
different.
quite
octandra
p.
distichously
are
gahniaeformis and G. affinis. On the other hand the flowers
flowered
very
223
GAHNIA
flower subordinate
imperfect
an
hexandrous,
habit
S. Australia,
Island,
Kangaroo
THE
OF
Kern,
(Brongn.)
Bot., Atl.
Duperrey, Voy.
comb.
Phan.
nov.
—
(1829)
Lampocarya
t.
29; text,
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G.
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.
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S.
G.
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