CAREX LUTEA (CYPERACEAE), A RARE NEW COASTAL PLAIN ENDEMIC FROM NORTH CAROLINA

9 Pages·1994·5.2 MB·English

by  R J Leblond

A
CAREX LUTE A RARE
A
(CYPERACEAE),
NEW
COASTAL ENDEMIC
PLAIN
FROM NORTH
CAROLINA
LEBLOND
R.J.
North Carolina Natural Program
Heritage
N
132 Road
orris
NC
Swamboro, 28584, U.S.A.
WEAKLEY
A.S.
North Carolina Natural Program
Heritage
and
Department Environment, Health, Natural
of Resources
Box 27687
P.O.
NC
27611-7687
Raleigh, U.S.
,
REZNICEK
A.A.
Michigan Herbarium
University
of
North Building
University
Ml
Ann
Arbor, 48109, U.S.A.
CRINS
W.J.
Natural
Ontario Ministry
Resources
of
Box 9000
P.O.
CANADA
POA
IKO,
Huntsville, Ontario,
Carex lutea (section Ceratocystts) described from the outer coastal plain of so
is
New
North
Carolina. the only specie cur south of Jersey ak
It is
Im
Atlantic Coast, and appears to be a calized endemic ofwe savannas underlam by
lo^
;t
From
deposits. all other species oft his section, C. lutea s distinguished by its pale
i
and
:ulms, elongate nflorescences(4.5)5.4-25(
i
long with usually only one or two widely separated pi stiUate spikes below the
Field surveys in 1991 by LeBlond of a
R.J.
i
nderlain by coquina limestone deposits on the ou
S]DA16(1) 1994
154
County, North Carolina disclosed an unfamiliar Carex with clear affinity to
and more with
the well-defined boreal section Ceratocystis, specifically the C.
&
complex defined by Crins Ball (1988, 1989a, 1989b). Sub-
flava L. as
sequent searches the plant by LeBlond and A.S. Weakley disclosed four
for
additional populations in Onslow and Pender counties. However, the popu-
km.
lations were clustered within a radius of about 4 Furthermore, only
all
the original population was large; the others consisted of fewer than 60
all
clumps
each.
Diagnostic characters of the Carex complex include globose to ovoid,
flava
more with
or approximate, short-peduncled to sessile pistillate spikes
less
&
the perigynia spreading (the lowermost often refiexed) (Crins Ball 989b).
1
Three species of the complex, C. cryptolepis Mack., C. flava, and C. vtridula
known none
Michx. subsp. viridula, are from the northern coastal plain, but
New & Two
has been found south of northern Jersey (Crins Ball 1989b).
(Andersson)
additional subspecies of C. vtridula, C. viridula subsp. oedocarpa
known
Schmid and Schmid, from
B. subsp. brachyrrhyncha (Celak.) B. are
Gulf
boreal habitats farther north along the Atlantic coast in the of St.
found
Lawrence and
region in Eurasia. Several other, distinct species are
elsewhere in the old world and in the temperate parts of the southern
North
hemisphere, but the relationships of the Carolina plants are clearly
with the North American members of the C. complex.
flava
number
Close examination of the North Carolina plant discloses a of
significant points of difference from the other species of the Carex flava
complex North America. The of the North Carolina plant
in pistillate scales
are pale yellowish-green, immediately separating from C. flava and most
it
subspecies of the of which are coppery or tinged with red
C, viridula, scales
mm
The
or brown. larger (up to 5.2 long), reflexed lower perigynia
(5.8)
may
separate from those subspecies of C, viridula that have paler scales.
it
The North from
Carolina plants can be separated the pale-scaled C. cryptolepis
perigynium
by its usually sparsely serrulate beaks, as well as its taller stature
and longer
inflorescences.
North from
Several features unique to the Carolina plant separate all
it
complex both North America and world-wide.
other species in the C. flava in
The North Carolina plant than any other members of the section, with
taller
is
cm
mature flowering individuals typically over 65 and reaching
taller tall
number
up m. Even though
heights of to 1.25 the plants are tall, the of pis-
As
spikes normally only one or two, extremely rarely three. well, the
tillate
is
North culms
inflorescences of the Carolina plants (particularly those of that
much
produce two pistillate spikes) are longer than any other species, the
18-41 members complex
longest ranging from cm. All other of the C. flava
much
cm, and
reaching heights of over 65 routinely pro-
are shorter, rarely
cm
ducing 2-3 spikes shorter inflorescences 1.5-12(20) long.
pistillate in
Based on unique morphology, and highly North
its this rare localized
new
Carolina plant here described
is as a species.
Carex
lutea LeBlond,
sp. nov. (section Ceratocystis). (Fig.
1)
mm
Styli marcesentes; stigmata Antherae 2.1-3.6 longae.
3.
3,
Plants cespitose in small to large (up to 45 culms) clumps, with
ca. fertile
short ascending rhizomes; roots pale brown, not densely with
felted root
mm
cm
culms
hairs; fertile (40)65-110(125) 0.6-0.9 wide base of
tall, at
lowermost more smooth
spike, central, or trigonous, except apex
less at
where
often slightly scabrous-angled, with glabrous, stramineous to pale
brown cm
bladeless basal sheaths. Leaves 3-7, mostly basal; blades 5.5-28
mm
much
long, shorter than culms, .8-3.8 wide, plicate, yellowish-green,
1
mm
glabrous, the margins antrorsely scabrous, the widest 2.4-3.8
leaves
mm
wide; 2.5-11 more
leaf sheaths long, or tightly enveloping culms,
less
band
glabrous, green; inner of sheath glabrous, whitish-hyaline, the apex
and more
thin friable, irregularly concave, or less truncate, or occasionally
mm
slightly prolonged; ligules obtuse, 1.4-3.6 long, the portion more
free
mm
or less entire, whitish-hyaline, to 0.7 long. Vegetative shoots 40-65(90)
cm
cm
tall; leaves 5-11, similar to those of fertile culms but up to 65(90)
mm
long and 4.6 wide, more or less evergreen (at least the proximal portions
cm
of the blades); pseudoculms 5-13 Inflorescences (4.5)5.4-25(41)
ca.
tall.
cm
with
long, all spikes quite separate, the lowest 2 pistillate spikes
(if
cm
present) (1.6)4.5-18(33) distant; spikes single nodes, ascending;
at
cm
lowermost spikes with peduncles 0.4-4.5(16.5) long, the uppermost
spike peduncles smooth and more
pistillate sessile; terete proximally, or
less
and
trigonous serrulate-angled distally; lowermost bracts usually reflexed
when cm
(except subtending long-peduncled with 5-2
blades long
spikes),
5
mm
cm
and 1.2-2.5 wide and sheaths (0)0.2-4 long, 0.5-1.3(1.9) times
as
much
long uppermost
as the inflorescence, the bracts also reflexed, bur
reduced. Spikes 2-3(4), the terminal staminate (very rarely with an addi-
tional small, accessory staminate spike the
at base), lateral pistillate (very
mm
7-
rarely with a small staminate apex up to 8 long). Terminal spikes
(9) 1
mm mm
39 long, 1.4-2.5 wide, 45-90-flowered, peduncles
(0.3)1-
ca.
2)cm
6(10. long, (0.1)0.7-2. 5(5.1) times as longas the spikes. Lateral spikes
mm
cm
8-11
0.7-2.7
long, wide, globose
to ellipsoid or short-cylindric.

s
LeBlond, Weakley, Reznicek,
CRINS, Carex 157
lutea
mm
mm
densely 15-60-flowered. Pistillate scales 2.1-3.3 long, 0.9-1.3
more
wide, lanceolate to narrowly ovate, obtuse to or acuminate,
less
glabrous, pale yellowish-green with a green center and wide hyaline
(sometimes stramineous-tinged) margins and apex, 1 -nerved, almost totally
mm
concealed by the crowded perigynia. Staminate scales 2.9-5.6 long,
mm
1.2-1.9 wide, narrowly obovate narrowly oblong, obtuse
to to acute,
glabrous, stramineous to pale brown with a green center and wide hyaline
mm
margins and apex, l(3)-nerved. Perigynia (3.5)3.9-5.2(5.8) long, 1.4-
mm
2.2 wide, spreading, strongly outcurved and squarrose in the spikes, the
lowermost strongly somewhat and asymmetri-
reflexed, inflated, irregularly
cally trigonous with convex, obovate sides, glabrous, bright yellow proxi-
mally, pale yellowish-green distally, short-stipitate and tapered to the base,
much
7-13-nerved with two nerves more prominent than the con-
rest,
mm
tracted into a strongly deflexed beak; beaks 1.4-2.2 long, finely and
sparsely serrulate or sometimes smooth, green, the apex bidentulate with
mm mm mm
teeth 0.2-0.5 long. Achenes 1.4-1.9 long, 1.2-1.5 wide,
trigonous with flat to slightly concave, strongly obovate sides, essentially
truncate brown, withering; stigmas Anthers
apically, sessile. Styles 3. 3,
SW
UNITED Hwy
North
Type: STATES. Carolina. Pender Co.: of N.C. 50, ca. 1,8 mi
NNW
WofOnslowCo. Rd
line, ca. 11 mi of Holly Ridge. S of secondary 1532,0.85 mi
SW
Hwy
May
of N.C. 50, "Lamer Quarry Savanna," 20 1993, A.A. Reznicek 8942 with S.A.
& Some MICH; BRIT/SMU, GA,
Rezmcek. LeBlond B.A. (holotype: FLAS,
isotypes:
R.J.
NCU, VDB,
TAES,
us,
herb. C.T. Bryson).
NORTH
CAROLINA. Onslow NE
Addirional specimens examined: Co.: side N.C.
NNW
Hwy
May
50, ca. 10.4 mi of Holly Ridge, "Powerline Savanna," 20 1992, A.A.
&
8954 (MICH, Pender
Reznicek with S.A. Rezmcek, LeBlond, B.A. Sorrie VPI). Co.:
R.J.
SW Hwy NC
Lanier Quarry Savanna, S of secondary road 1532 0.85 mi of 50, Apr 1990,
1 1
May
LeBlond 1188 (NCU); 24 Apr LeBlond 1983 (NCU); 22
1991, RJ- 1991,
R.J. R-J-
LeBlond 2056 (MICH, NCU); 27 Jun LeBlond 2267 (NCU); 20 Apr
1991, RJ. 1992,
R.J.
LeBlond 2723 (NCU); Sandy Run Savanna along Hunt Club Rd miS;ofHwyNC50,
).5
(
May & D.lmiNofHwy
12 1992. A.S. Weakley LeBlond .«.(NCU);WarkinsSaLvanna,
R.J.
1
,
.5miWoftheOnslowCo.li May &
N.C. 50ca. ne, 12 1992, A.^ Weakley R.J LeBlond
.
NNW
,r,«,(NCU);N sideN.C.Hwy50,ca.lmiW^ofOnslowCo.line,ca .11.5m of Holly
a
May
Ridge, "Waclcms Savanna," 20 1992 A.A. Rezmcek 8949 with A. Reznicek,
S.. R.J.
,
&B.. (MICH, USCH).
LeBlond
Sorrie
\.
DISCUSSION
&
In the key to the Carexflava complex in Crins Ball 989b), C. lutea keys
(1
closest to C. cryptolepis because of its pale, yellowish-green scales, narrow
and The
leaves, perigynia of similar size. overall yellowish-green color of C.
C
lutea also similar to that of Insertion of the following couplet
is cryptolepis.
in place of the lead of couplet however, will complete the key, and
first 3,
Irom
allow easy separation ot C. lutea C. cryptoLepis.
times as long as the inflorescence; staminate spike peduncles mostly 0.7-2.5
mm
perigynium
times long the staminate spikes; achenes 1.2-1.5 wide;
as as
beaks often sparsely serrulate C. lutea
as long as the inflorescence; staminate spike peduncles 0.2-0.5 times as long
C. cryptolepis
Although Carex lutea keys with C. cryptolepis due to its pale scales, its
most
elongate inflorescence similar in aspect to that of C. vindula subsp.
is
and
brachyrrhyncha var. elatior{^ch.\td\.) Crins (C. lepidocarpa Tausch), a boreal
subarctic taxon of highly calcareous, open wetlands in the Gulf of St.
Lawrence region and Europe. Carex most obviously from
lutea differs C.
and
viridula subsp. brachyrrhyncha var. elatior in plant size, inflorescence size,
paler The two taxa can be separated by the following couplet.
scales.
Pistillate scales pale yellowish-green, nearly the same color as the perigynia
1.
and thus inconspicuous; culms 65-1 10(125) cm; longest inflorescences
tallest
among
brown
Pistillate scales with coloration, conspicuous the greenish to
1.
yellowish perigynia; culms (10)20-60(85) cm; longest inflorescences
tallest
cm
2-12(18) long vindula subsp. brachyrrhyncha
C. var. elatior
In addition to the scale color and size differences, Carex lutea differs from
C. viridula subsp. brachyrrhyncha var. elatior in inflorescence proportions. In
C. lutea, the bracts of the lowest pistillate spikes are shorter than or equalling
the inflorescence and most staminate spikes are shorter than their peduncles.
In C. viridula subsp. brachyrrhyncha var. elatior, the bracts of the lowest
pistillate spikes often equal or exceed the inflorescence and most staminate
spikes are longer than their peduncles. Because of the great variability in
number
these proportions due to differences in the of pistillate spikes in the
and depending on
inflorescence the considerable plasticity of inflorescences
modest
the vigor of the plants, there overlap in these proportions,
is
them
rendering unsuitable as key characters. Carex lutea also has proportion-
ately narrower leaves than C. viridula subsp. brachyrrhyncha var. elatior.
Although a significantly shorter plant than C. lutea, the widest leaves of C.
mm
viridula subsp. brachyrrhyncha var. elatior range up to 5.6 whereas those
mm
most Other
of C, lutea are at 4.6 wide. differences include the larger
mm
C
much
which up
staminate spikes of lutea, are to 39 long, larger than
mm
maximum
and
the of 25 in C. viridula subsp. brachyrrhyncha var. elatior,
mm
perigynia up long whereas those of
larger to 5.2(5.8) in C. lutea C.
mm
up
viridula subsp. brachyrrhyncha var. elatior are only to 4.2 long.
It tempting to suggest that the character of pale scales, which uniquely
is
defines the two North American endemics, C. cryptolepis and C. lutea, indi-
LeBlond, Weakley, Reznicek, Crins, Carex 159
lutea
cates a close relationship. However, until genetic, breeding system, and
micromorphological evidence comparable to that available for the other taxa
known
for C. lutea, statements of putative relationship are speculative.
is
when
Nevertheless, a character compatibility analysis was run with C. lutea
Crms
added to the data matrix of 990), C. lutea consistently clustered with
( 1
Although
(unpublished genetic and micromorphological
C. cryptolepis data).
and
data are not yet available for C. lutea, can be recognized readily
it
The
ecology of C. lutea quite distinctive within the section; not
is
surprisingly, since its occurrence is so far removed from all the other species.
All the occur sandy overlying coquina limestone and
sites in soils deposits,
the species shows a preference for the ecotone between the longleaf pine
swamp
savanna and nonriverine communities. from Lanier
forest Soil a
pH pH
Quarry microsite for C. lutea had a of 5.6. This similar to levels
is
recorded Thalictrum H.E. Ahles microsites the Lanier Quarry
at cooleyi at
Savanna. Thalictrum the most frequent of and
cooleyi associate C. lutea,
is is
similarly restricted in distribution. Soils not supporting T. cooleyi at the
pH
Lanier Quarry regularly lower
site test at levels.
Most
Carex lutea plants occur in the partially to moderately densely tree
shaded savanna-swamp ecotone, with scattered shrubs and a moderate to
dense herb layer. The savanna-swamp ecotone subject to occasional to
is
frequent which favor a herbaceous ground layer and suppress shrub
fires
dominance. Carex lutea a subdominant to patch dominant at two of the five
is
known
sites. Occurrences are densest in areas of partial to moderate tree
shading with an absence of a shrub understory. Frequent associates include
Taxodium ascendens Brongn., Liriodendron Acer rubrum Myrica
tulipifera L., L.,
Thalictrum Carex
cerifera L. var. cerifera, cooleyi, Aletris farinosa L., lonchocarpa
Osmunda
Willd., regalis L. var. spectabilis (Willd.) A. Gray, Physostegia purpurea
and Michx.
(Walter) Blake, Parnassia caroliniana
S.F.
Though might
the height oi Carex lutea suggests that be easily found,
it
the plants are slender, occur in areas with substantial graminoid cover, and,
may
except for one are rare and localized. Thus, a colony remain quite
site,
inconspicuous, even in fruit. This suggests the possibility that additional
coastal plain, though the association with narrowly endemic species in an
may
unusual habitat suggests that C. lutea be a highly localized species.
The
occurrence of a localized disjunct species of the boreal Carex
flava
complex on the outer coastal plain of North Carolina quite striking. This
is
km
known
constitutes a disjunction of about 750 from the nearest popula-
members com-
tions of other of sect. Ceratocystis. In Eurasia, species of this
The
plex occur south Spain, Morocco, Turkey, and most sub-
as far as Iran.
among
stantial range separation close relatives in Europe that between C.
is
&
vlridula subsp. brachyrrhyncha vars. elatior and nevadensis (Boiss. Reut.)
Crins from southeastern France southern Spain 800 km).
to
(ca.
The type locaHty of Carex Lanier Quarry Savanna, and the other
lutea,
locations where has been found are ecologically highly unusual and phyto-
it
geographically notable. The combination of open conditions under-
fairly
Over
lain by a calcareous substrate very rare on the Atlantic coastal plain.
is
26 regarded North Carolina by the Natural Heritage
species as rare in state
Program are found at the Lanier Quarry site. Nine of these are listed as
endangered, threatened or candidate species by the U.S. Fish and Wildlife
Many
service. of these rare plants have very restricted distributions, either
The
being endemic to small areas or with highly scattered occurrences.
of these taxa are variable, but include connections to the calcareous
affinities
savannas of the Gulf Coast alkaline marshes of the Atlantic tidewater,
states,
and Appalachian and
calcareous glades, barrens, prairies of the region,
New
pinelands of the Carolinas and southern Most notable the
are
Jersey.
two endemic species closely associated with Carex Thalictrum
lutea, cooleyi
and an undescribed species oi Allium. Thalictrum endemic to about
cooleyi is
a dozen sites, all savanna margins in sites underlain by calcareous deposits,
North and
in Carolina, Georgia, Florida. has the highest ploidy level
It
known (30x more
in the genus at2n = 2 suggesting derivation from a
10), its
The
widespread northern and inland species such as revolutum (Park 992).
T.
1
undescribed Allium related to the widespread inland species A. cernuum
is
Roth and A. stellatum Ker and known from only four of them shared
5 sites,
is
with
C. lutea.
calcareous deposits have evidently served as a small archipelago of phytogeo-
graphic islands for species poorly adapted to present conditions on the
southeastern coastal plain. seems likely that Carex lutea a narrowly
It is
may
distributed, very rare endemic. It reflect a southern extension of the C.
flava complex during the Pleistocene glaciation, followed by isolation in a
few suitable sites and speciation. Alternatively, C. lutea could represent the
relictual occurrence of a formerly more widespread and older species in the
C/^m
complex.
We
North Carolma The Natu
are grateful to the chapter of
providing funding systematic survey of the of
for for a flora
it
which new
preserve, resulted in the discovery of this specie
LeBlond, Weakley, Reznicek,
Crins, Carex
lutea
Crins, WJ. and W. Ball. 988. Sectional limits and phylogenetic considerations
P.
1
section Ceratocystis (Cyperaceae). Brittonia 40:38-47.
North America and northern Eurasia. Numerical taxonomy and character analy
I.
67:1032-1047.
Bot.
J.
Crins, W.J. and P.W. Ball. 1989b. Taxonomy of the Carex complex (Cyperj
fiava
1065.
A
M.M.
Park, 1992. biosystematic study oiThalictrum section Leucocoma (Ranunci