Table Of Content.
VOLUME NUMBER
AMERICAN FERN JOURNAL:
67
83 2 (1993)
A
Undescribed
Previously
hawaiiensis:
Isoetes
from Hawaii
Quillwort
W. Carl Taylor
Milwaukee Museum, 800 W. Wells Milwaukee, Wisconsin 53233
Public Si.,
W. Wagner,
H.
Jr.
Ann Michigan 48109
Herbarium, University of Micliigan, Arbor,
Hobdy
Robert W.
Land and Natural Resources, 54 S. High St., Wailuku, Hawaii 96793
Warshauer
R.
F.
RO. Box Volcano, Hawaii 96785
192,
from
botanists
The pteridophytes of Hawaii have received relatively little attention
have
during the past half-century. However, intensive recent studies in the islands
named
revealed a number of previously undescribed species, including the quillwort here.
Between 25
Quillworts have been found Hawaii several times since early this century.
in
from pools atop
September and 17 October 1917, Charles N. Forbes discovered Isoetes
Eke Maui M. BISH). Forbes did not recognize his col-
Mt. on of (Forbes 682.
Uie island
E
when R. Warshauer collected
be was not 17 October 1977,
lection to Isoetes. until
It
&
Hawaii (Warshauer
Mauna Kea on island of
Isoetes from the east slope of the
was quillwort
a native
McEldowney 1500 BISH), Hawaiian botanists realized there
that
Eke
on summit of Mt.
Robert W. Hobdy again discovered Isoetes in pools the
in Uie flora.
same
more from
once the site
on 23 October 1980 (Hobdy 931 BISH), and he collected
it
and
specimens
MIL
5658 and
Eke
Mt. (Taylor 5332,
species
Isoetes
& - Holotype
W. C. Taylor W. H. Wagner, sp. nov.
M
Mt. Eke. Forbes
682.
fusiformis
subglobosum
Sporangium
cm ±
dimidio tegens.
usque ad 25 longa,
virenlia, gracilia,
numerosas
mm
±10-20 megasporas vel
±2-3
non pigmentifero,
diametro, pariete
manifeste
obscure vel
475-650 diametro,
[an
Megasporae
microsporas albae,
continens.
30-4^
brunneae,
Microsporac pallide
1-4)
fusiform
or
cylindrical
brown, subglobose to
Rootstock
Roots
accommodate spo
toward base to
abruptly dilated
diameter,
arranged
rangium, gradually tapered to apex, spirally
mm
wall
±2-3 diameter,
in
Sporangium subgloblose,
Megaspores
numerous microspores.
rO-20 mecasnores or
um
30-4
Microspores brown,
light
VOLUME NUMBER
AMERICAN FERN JOURNAL:
83 2 (1993)
68
4J -ndVJn
v_F
Figs. 1-6. Isoetes
hav^'aiiensis plants, spores, chromosomes, and
of hawaiiensis
habitats. Fig. Tliree plants
1. /.
pool
SEM
J |iin. Fig. 3. photomicrograph of two hem
/.
|iin. Fig. 4. Brightfield photomicropraDh of/, /wk
Qiromosomes
lip squash.
stained wiUi Wiltman's hematoxylin. Fig. Shallow ponds on summit of Mt. Eke
5.
ensis. V\g, 6. hawaiiemis rooted
/.
QUILLWORT FROM
TAYLOR HAWAII 69
ETAL.:
hawaiiensis known only from top of Mt. Eke on the island of
Presently, Isoetes is tlie
Mauna Kea
Maui and from slope of on the island of Hawaii.
the east
Mt. Eke, a peak on the northeast side of the West Maui Mountains, is shrouded in near-
m
6000
Annual estimated be about
perpetual mists 1375 elevation. precipitation is to
ly at
mm. Mt. Eke's summit the remnant core of a volcanic trachyte dome, roughly circular
is
shape and topped
flat
ponds
approximately 100,000
summit of Mt. Eke about 0.4 hectares in area, harbor
the total
and appear be only habitat for Isoetes in this region.
individuals of hawaiiensis, to the
/.
some of
Aldiough the shallow ponds on Mt. Eke appear to hold water most of llie time,
the ponds occasionally are witliout standing water. Similar ponds at higher and lower elc-
Mau
montane bogs of west
Mt
and
intertwined
10-15 with roots
individuals Uieir
The
lawn largest
impression of a sparse (Fig.
distance, Uiese aggregations give the 6).
8-10 cm The pond margins, which are most subject
occur water averaging deep.
plants
in
to periodic drying, are usually devoid of Isoetes.
Mauna Kea
located
of arc in
known on slope
The populations of hawaiiensis the east
/.
m
montane about 850 elevation,
two adjacent stream channels within a rainforest at
grow
km about 50 100 plants
approximately 17 norUiwest of Hilo. At Uiis location, to
stream courses.
rock forming the
lava
close together several patches attached to
in
mm.
7600
be about
Annual area estimated to
precipitation in this is
and extensive,
polymorphic rootstock
its
Noteworthy of hawaiiensis are
features its
/.
species.
unifonn shape for a particular
usually in
matted Rootstocks of Isoetes are
roots.
more horizontally
may grow centimeter or eiUicr
a
However, rootstocks of hawaiiensis
/.
cylindrical root-
Occasionally,
become
become cylindrical.
fusiform or vertically to
to
Roots of
or variously lobed. /.
and clavately lobed,
stocks are dilated distally are clavate,
Such exten-
of plant.
longer than the rest tlie
numerous, and often
hawaiiensis
are slender,
mud. These roots are
anchor plants securely in soft
needed
sive roots are probably to
plant
species
continent or island.
brought from a distant
and divergence of plants
isolation genetic
deposited
arrn
Progenitors of hawaiiensis possibly
/.
Tins
known
Mallard to eat Isoetes.
For example, the is
bodies of migratory waterfowl.
m
breedmg ground.s
from
presumably
Hawaiian Islands its
duck
occasionally reaches the
Canada Goose, which also has
227-233). Tlic
western North America (Berger, 1981. p.
lowland wetlands.
Hawaiian
the
an iiTCgular visitor to
been observed devour
to Isoetes, is
While North American
.,..„—..
.
-
appear be
of Isoetes to
American species
^_
__„...
,
no records of ducks or geese fre-
are
quitrdimTemVoTn Second, there
I'/imv^/irt.^/.v.
Eke
region.
summits
quenting Mt. Eke or the west forest in tlie
come from L taiwa-
have the
could
hawaiiensis
seems more progenitor of
a
It likely /.
cold water,
group of high elevation,
complex a
nensis complex. The taiwanensis is
/.
New Taiwan
Zealand
from to
rim
western Pacific
island species occurring along the
a basic
taiwanensis
is
& hawaiien.us,
For example, like I.
(Britton Brunlon, 1991). /.
taiwa-
Furthcnnore.
microspores.
megaspores and echinate /.
diploid. also has rugulatc
It
NUMBER
VOLUME
AMERICAN FERN JOURNAL: 83 2 (1993)
70
pond on norUiern Taiwan near the top of an extinct vol-
shallow
nensis occurs in a small,
m
Whereas Isoetes taiwonensis is dis-
1000 (DeVol, 1972).
cano an elevaUon of about
at
megas-
corm, and smaller
from hawaiiensis by lack of a velum, irilobed
tinguishable its
/.
pm
400 diameter and less than 30 ^tm
which average Uian in
pores and microspores less
chromosome number,
taiwanensis similar to hawaiiensis in
in length, respectively, is /.
/.
complex
An from taiwanensis
hawaiiensis
and ancestor of/, tlie
spore textures, habitat. /.
Golden Plover which winters
could have reached the Hawaiian Islands via the Pacific
New
Zealand,
from China, Taiwan, and the Hawaiian Islands south to Australia,
India,
breeding grounds on the tundra
Samoa, and Oceania. In spring this plover migrates to its
abundant
The Golden Plover an
Pacific is
of northern Siberia (Johnscard, 1981, p. 135).
Mt
grows(Berger, 1981,p. 231).
LEDGMENTS
We Botany Department, Bishop Museum, William R.
from Jane A. Medler,
are grateful for as.sistance
Hawaii-Manoa, K. Frey,
Anderson, Herbarium, University of Micliigan, Daniel D. Palmer, University of Jill
University of Wisconsin- Milwaukee, and Qien-Meng Kuo, National Taiwan University.
CmzD
Literature
Berger, Andrew 1981. Hawaiian Birdlife, 2nd ed. University of Hawaii Press, Honolulu, Hawaii.
J.
Britton, Donald M. and Daniel Brunton. 1991. The spores and affinities of Isoetes taiwanensis
F.
Fern Gaz. 14:73-81.
(Isoetaceae: Pteridojjliyla).
DeVol, Charles E. 1972. Isoetes found on Taiwan. Taiwania 17:1-7.
JoHNSGARD, Paul A. 1981. The Plovers, Sandpipers, and Snipes of World. University of Nebraska Press,
tlie
Lincoln, Nebraska.
