MARSILEA MINUTA (MARSILEACEAE): NEW TO FLORIDA AND NORTH AMERICA

5 Pages·1995·2.4 MB·English

by  James R Burkhalter

NEW
MARSILEA MINUTA TO
(MARSILEACEAE):
AND NORTH
FLORIDA AMERICA
BURKHALTER
JAMES
R.
Michael Herbarium
Cousens
I.
Room 120
Building
38,
University West Florida
of
PL
Pensacola, 32314, U.S.A.
newly
reported introduced
re as for Floric
introduction via waterfowl and
if its its pc
ABSTRACT
Condado como
de Escambia,
Florida,
ret
1
An
obviously spontaneous population of the primarily tropical water-
clover fern Marsilea mtnuta L. has been found growing in a streetside ditch
the northwest corner of Lownde Avenue and Grundy
at Street in a residen-
tial subdivision on the southwest side of the Pensacola area in Escambia
At
County, Florida. the time of discovery was realized that the nearest
it
documented many
sites for Marsilea in Florida were kilometers to the east
m
m
and south the penmsula (Ward and Hall 1976; Johnson 1986) and
&
Apalachicola (Anderson 1986) for the species M. vestita Hook. Grev. and
westward in Mobile, Alabama, for M. macropoda Engelm. ex A. Braun in
Kunze
(Burkhalter 1989). It was also realized that Marsilea in the Pensacola
new new
area constituted a county record and a species of vascular plant for
the entire western Florida panhandle (Clewell 1980; Wilhelm 1984). Only
—
the genus of the water-clover fern, namely Marsilea a taxonomically dif-
—
ficult group was recognized at the time of discovery, so a sporocarp-bear-
May
ing specimen {Burkhalter 13220) collected 3 1992 was sent to David
M. Johnson Ohio Wesleyan
of University for determination. Dr. Johnson
identified as Marsilea minuta L. (Johnson 1986). Duplicates of that speci-
it
UWFP
men
were deposited Additional specimens
at (Fig. fertile
1).
{Burkhalter 13304) collected at the discovery site 19 June 1992 were sub-
UWFP,
sequently deposited FSU, FLAS, USE, and NY. According
at to the
comm.
information provided by Dr. Johnson (pers. 27 August 1992)
-
SiDA 16(3): 545 549. 1995
MO
SiDA 16(3)1995
Mantka
new
iiinima hereby reported Florida and North America
is as ro
Comm.
N. Amer.
(also see Flora Hd.
1993,
333).
p.
At
the discovery minuta dominant
site Al. the vascular species the
is in
m
60-cm-deep
described
ditch for a distance of approximately 30 north-
ward from
the stated intersection. Associated
species in this section of the
ditch include Hypericum mutilum, Ludwigia
decurrens, Hydrocotyle umbellata,
]
Mikaniascandens, Upocarpha Pam-
maculata, uncus
Paspalumurvillei,
elliottn,
cum
repem, Sacctokpis Thelyptens and Osmunda The
striata,
palustris,
regalis.
composed muddy
substrate of black mixed with and
is silt tan sand, stand-
ing or running water almost constantly To
is present. the south of the in-
tersection the ditch very shallow and grades
into adjacent
is residential
There
lawns. only a few scattered individuals of M. minuta occur over
a
m
distance of approximately 20
in association with
Lilaeopsis attenuata,
Cardamtm
and lawn
pensylvanica, This
grasses. section of the ditch sub-
is
m
mowing.
jected to periodic Less than 250 southward
the ditch drains into
Bayou
Grande,
a large lagoonlike extension off the western side of Pensacola
A
Bay. detailed search of ditches and other low moist
all habitats the
in
general geographic area has revealed that M. minuta occurs only in the ditch
An
where was discovered. interview with Andrew who
it Lucas,
L. resides
from
across the street the M^m/e^-containing
ditch, has provided informa-
me
which
tion leads to conclude that the M. minuta colony not very old
is
and perhaps became
established than
less five years prior to discovery.
its
Marstlea mtnuta primarily
is tropical in its eastern hemisphere distribu-
common
tion (Johnson There
1986). it occurs as a and widespread weed in
and
Africa India. In the western hemisphere, where
introduced, has
it is it
known
been
heretofore only from the islands of Trinidad and Tobago and
from ofPernambuco
the
state in eastern Brazil (Mickel Johnson
1985; 1986).
New
The World
colonies occur low
at elevations near the coast freshwa-
in
ter or occasionally brackish habitats (Trinidad and Tobago)
or in seasonal
ponds
(Brazil).
The how
question of M. minuta became
introduced
into the Pensacola
area deserves consideration. Johnson
(1986) has reviewed
the literature con-
cerning long-distance Mars
dispersal o^ ilea sporocarps in the digestive tracts
of migratory aquatic and mode
birds; this of transport
for certain species of
Marstlea, particularly via various ducks (genus Anas, and
possibly also Atx),
uncommon
is an established fact and a not occurrence. Dennis and Webb
commented
(1981) have on
similar long-distance
dispersal oiVtlularia spo-
by
rocarps waterfowl. thus seems apparent most mode
It that the probable
M.
of introduction of minuta
into the Pensacola
area long-distance sporo-
is
carp transport via waterfowl from South America. This
particularly likely
is
in view of the proximity of the discovery waterfront (Bayou
site to a area
Grande)
by migratory
visited waterfowl and number
the
fact that a of

migratory waterfowl with
species suitable dietary habits (including
species
oiAnas and Porphyrula) use flyways which pass over Pensacola and the known
M.
sites for minuta in Brazil, Trinidad, and Tobago Pough Weston
1951,
(cf.
&
Kale Maehr Of
1965; 1990; Ffrench 1991). course, one bird transport-
ing one sporocarp would
that have been required
is all to initiate the sub-
ject colony of minuta near Pensacola.
y\4.
More
two
than
years of observations have revealed that Marsika minuta
is evergreen in the Pensacola area and that easily withstood two days of
it
and
near- below-freezing temperatures on 12-13 March
1993 and another
unusually cold period on 17-18 January 1994. These together with
facts,
documented
the invasive and weedy
tendencies of this fern in other areas
(Johnson 1986), lead to the conclusion that M. minuta indeed
has the po-
become
weed some
tential to a of importance throughout
the southeastern
United
States. Suitable habitats for possible invasion by M, nitnuta include
roadside sunny
ditches, edges of freshwater and brackish marshes and
swamp
and
forests, other similar low moist Based on
the luxuriant
sites.
growth M,
of minuta
in the ditch at the discovery there some con-
site,
is
would grow
cern that vigorously became
it as if it introduced into other
similar
sites. Fortunately, as of this writing, this interesting invader from
South America
apparently
is restricted to the single streetside ditch where
am
David M.
grateful Dr. Johnson
to
I
for specific identification of
Marsika
minuta specimens
cited in this paper. also thank local ornithf
I
W.
Milmore
gists C. and Robert and Lucy Duncan
sharing
for their
ex]
and
tise information concerning possible avian
vectors.
REFERENCES
Anderson,
Noteworthy
L.C. 1986. plants from north Florida. Sida 11:379-385.
II.
BuRKHALTER,
MaYsika
1989- macropoda—stiW weed
J.R. a [in Mobile, Alabama}. Fid
H
America
Editorial Committee.
1993. Flora
c
and Gymnosperms. Oxford NY.
Univ.
!S Press,
New
1986. Systematics of the World
species
c
Maehr.
d D.S. 1990. Florida's birds. Pineapple
]
New
1985.Tnmdad lophytes. York Bot. Garden, Bronx, N'
,J.T.
&
Boubleday Garden Cir
bird guide. Co.,
sr
oiMarsiha
Re-introduction into Floi
vestita
.
56:113-115.
Jour.
1
Timbers
Florida. Tall Re;
1
3tSmv!?^rbIndde