NOMAPHILA STRICTA (ACANTHACEAE), A NEWLY DISCERNED AQUATIC WEED IN TEXAS, AND THE FIRST REPORT FOR NORTH AMERICA

3 Pages·1992·1.9 MB·English

by  T P Ramamoorthy

A
A
NOMAPHILA
(ACANTHACEAE),
STRICTA
WEED
NEWLY
AQUATIC
DISCERNED IN TEXAS,
AND NORTH
THE REPORT FOR AMERICA
FIRST
RAMAMOORTHY^
T.P.
Department Botany. Insthuto Biolo^ia
of
cle
Universidad Nacional A//tonoma de Mexico
MEXICO
Mexico
City.
TURNER
B.L.
Depart Botany
}nent of
Texas
University
of
TX78713,
Austin, U.S.
ABSTRACrr
An aquatic weed, Nrm/aphi/a new to North America, was discovered in San Felipe
stricta.
Springs, east of Del Rio, Texas, 0.2 mi., Val Verc!e Co., Texas, where was well-estabhshed and
it
vigorously reproducing by subsurface stolons. The species was apparently recently introduced
from the paleotropics and should be carefully monitored by ecologists interested in aquatic
ecosystems in the southwestern U.S.A. and adjacent Mexico.
Keywords: No?naphila, Hygroploila, Acanthaceae, aquatic weeds, Texas.
member
In September of 1991 the junior author, while collecting an aquatic
,
of the family Asteraceae {Trichocoronis rivularis A. Gray), observed and collected
an aquatic plant new to him. Indeed, upon further investigation, he was unable
any North American manual purporting account
to position the species in to for
& &
Wooten
97 Godfrey
the aquatics of this region (e.g. Correll Correll 1 2 1 979;
, ;
^tc^. The plant was thought to be, possibly, an undescribed species of the
first
aquatic genus Hygrophila (Acanthaceae), but the peculiar bilabiate corolla, palate
much
and branched
lower inner petals, the exserted, (albeit axillary) inflore-
scence precluded any close relationship with the North American species of
that genus.
Since the plant concerned was abundant and occurred in San Felipe Springs,
a well known collecting site visited by numerous botanists (beginning in 1849
seemed would not
with the of Charles Wright), unlikely that the species
visit it
we might
have been collected by yet other workers. Thus, felt that the species
prove to be an exotic introduction.
members
The author experience with paleotropical of the Acanthaceae
senior
s
'Present Address: Visiting Scholar, Plinit Reso/ares Ceiiter, University of Texas at Austin,
TX
Amtim
78712, U.S.A.
115-117.
SiDA 1992
15(1):
116
SioA 1992
15(1):
him
directed to the ^enus Nomaphila, a segregate from the world wide weedy
genus Hygrophib. Subsequent showed
research the species to h^No?miphila strkta
known
weed
(Vahl) Nees, a well aquatic of Malaysia (Backer
1965).
The
weed
introduction of this aquatic into San Felipe Springs was probably
We
dumped
accidental. surmise that was into the stream, unintentionally, by
it
someone on minnows
intent releasing or "gold lish" into the streams concerned.
The
proximity of the springs to Lackland United States Air Force Base, Del Rio,
home
Texas, which to numerous well travelled service men, often accompanied
is
by Asian makes
their wives, this a possibility. Regardless, the plant, which
-
emerges from the water for 30 80 cm, always along the stream banks, well-
is
established on both sides ofrhe stream leading from San Felipe Springs. Since the
several colonies occur along the banks of San Felipe Springs which soon empties
Rio Grande
into the might become
River, possible that the species an
it is
obnoxious weed
in soudiern Texas and Mexico. Aquatic should
ecologists
monitor
closely the spread of this taxon; perhaps removal the present time
at
might seem
expedient, since it does appear to compete, in part, with the Iocali:^ed,
probably
threatened, aquatic
species, Trichocoronis rividarh.
A
brief account on the taxonomy, nomenclature, and
a description of the
species follows:
Nomaphila
Nees
stricta (Veihl) in Candolle, Prodr. 11:84. 1844. Based on
E
Symb.
Just/da str/ctaV'cihl^ Bot. 1791-
6.
II.
&
Hygropbilii slruh/ (Nccs) Lindau in Englcr Prancl, Nacurl, Planzenf. IV. 3b. 297 895 non
. 1 .
Ilygrop/j/la strichi Hassk., Cat. Bot. Bo^or. M(S. 184-1.
m
Stoloniferous or rhizomatous aquatic herbs to about Stems 4-angled,
tall.
1
-6
cm
glandular-villous, the nodes thickened. Petioles 2 long; leaf-blades elliptic
6-15 2-7
cm cm
oblong, long, wide, acuminate above, obtuse below, with
about 16 pairs ofparallel secondary veins, entire to subcrenate. Inflorescence ax-
mm
4-6
cymose, the branches glandular-
illary, hairy. Bracteoles none. Pedicels
Calyx
long. glandular-hairy, of unequal
5 linear lobes, the posterior ones longer,
mm
7-10
cm
long, the anterior 2 shorter, 0.6 long. Corolla tube
ca. hairy,
tlie
mm
mm
whitish, ca. 5 long, the limb lilac, the upper lip broadly elliptic, ca. 12
mm
mm
long, 0.8 wide, concave and hood-like, shortly bilobed, the lower 2
ca.
1
mm
long, 8 wide, broadly
ca. elliptic, palate, 3-lobed, the lobes of equal length,
the laterals slightly wider than the obliquely velutinous middle
plicate, lobe.
Stamens
included, conspicuously didynamous,
4, the filaments glabrous, the
mm mm
longer ones 6
ca. long, the shorter 2 long, anther two-celled,
ca. ca.
mm
Ovary
1.5 long. densely glandular-hairy, 2-celled, multiovulate, die
style
ca.
mm
12 long, pubescent, the anterior stigmatic lobe longer.
Nomaphila
{Aainthaceae-Contortae-Uygrophileae) apaleotropical genus, recog-
is
nized by cymose
its axillary inflorescence, glandular-hairy calyx with unequal
and
lobes the palate, villous to velutinous, lower lip of the corolla. Various authors
have often considered to belong to Hygrophila Nomaphila) but our view
it (sect. in
Ramamoorthy and Turner, Nomaphila 117
The
the two differ taxonomically in significant ways. eglandular calyx with equal
lobes, and the axillary clusters (sometimes solitary) of flowers, readily distinguish
Up
now
Hygrophila from Nomaphila. until there have been no reports o^Nomaphila
becoming Americas, and discovery here of
naturalized in the so its is interest.
Correspondence with some of the larger herbaria in the U.S.A. revealed only two
collections oiNomphila, both from indoor cultivation {Pohls.n, US; and from an
,
CAS, comm.). Pohl comm.)
aquatic nursery in California, T. Daniel, pers. (pers.
US
notes that "The original source [ofthe collection ofN. strkta] was undoubtedly
Florida, which produces most of the aquarium plants used in the U.S. This species
name
widespread in the aquarium trade and under the of water wisteria',
sells
is
a highly ridiculous term."
Daniel comm.), reading our paper, noted that an almost identical
(pers. after
situation to that oiNinnaphila of Texas has occurred "in Florida with Hygrophila
&
He
polyspermia (Les Wunderlin 1981), an aquarium weed that escaped." further
we make
suggested that check the article concerned "to certain that the plant
Our
same examination
identified as H. polysperma in Florida not the as yours."
is
of the paper concerned leaves no doubt that the two plants are markedly different.
Hygrophila on the other hand represented in Texas streams by H. lacustris
is
Nees. should be noted that Nomaphila were retained in Hygrophila
It also \i it
would new combination name, name H. (Nees) Lindau
require a or the stricta
being preempted by the earlier H. stricta Hassls., as noted above.
TEXAS:
Specimens examined: U.S.A. Val Verde Co.: San Felipe Springs, growing in water
m N
along E bank ca. 40 of rhe bridge on hwy 90, 13 Sep 1991 S. Tz/vfjer 16020 (TEX); same
,
MO,
Oct 16032 (GH, SRSC, TEX).
localicy, 12 1991, B. Tmiier
SW
OLD WORLD:
MALAYSIA.
Celebes: northern central part, on the coast of Dongala,
INDONESIA.
Meijer 10133 (US); Johore, Kota Triggi, S/miair 8425 (US). Timor: Kumlol,
THAILAND.
Sa/mur 83 (GH). Tahsaeh: Ban Nah Saan, Group Maxwe/i 87-62 (GH).
15,
ACKNOWLEDGMENTS
We Gwylum Kew who
Mr. Lewis of faxed xeroxes oi Nomaphila
are grateful to
specimens from K, which confirmed the Texas plant's identity, and curators
stricta
GH
US
of and loan of specimens. Mr. TJ, Patterson kindly collected
for
additional material of the species at our recjuest, and largely responsible for
is
Richard Pohl helped providing
observations as to the distribution discussed. in
Thomas
information, noted, and Daniel reviewed the manuscript
useful
eis
comments.
including additional helpful
REFERENCES
Backer, C.A. 1965. Flora of Java 2:57 Noordholf-Groningen, Netherlands.
1
.
CoRRELL, D.S. and H.B. Correll. 1972. Aquaric and wetland planes of soudiwestern United
Washington, D.C.
States. E.P.A.,
Godfrey, R.K. and J.W. Wooten. 1979. Aquatic and wetland plants of southeastern United
States. University of Georgia Press, Athens, Ga.
Les, D.H. and R.P. Wunderlin. 98 llygropbilapolyslm-nia (Acanthaceae) in Florida. FloridaSci.
1 1
.
44:189-192