XYRIS SPATHIFOLIA (XYRIDACEAE), A NEW XYRID FROM THE KETONA DOLOMITE-LIMESTONE GLADES OF ALABAMA

2009·14.6 MB·English

by  Robert Kral

NEW
FROM
A THE
XYRID
XYRIS SPATHIFOLIA (XYRIDACEAE),
ALABAMA
KETONA DOLOMITE-LIMESTONE GLADES OF
Mincy
Robert Moffett,
Krai
Jr.
J.
Georgia Department of Natural Resources
Botanical Research of Texas
institute
500 4th Resources Division
Wildlife
Street
E.
Nongame
Fort Worth, Texas 76 02-4025, U.S.A. Conservation Section
1
Program
Georgia Natural Heritage
2065 Highway 278
SI.
U.S.
USA.
Georgia 30025-4743,
Social
Circle,
[email protected]. us
h
X. spathifolia
scies, is
INTRODUCTION
new
North America
complete,
Despite the pervasive notion that cataloging of the vascular plant flora of is
occur temporal
species continue be discovered. Frequently, these discoveries in spatial or clusters, re-
to
Alabama
vealing a botanical "hot spot," as in the case of the Ketona Glades of Bibb County, (Ertter 2000),
10-12
located the extreme southern edge of the Ridge and Valley Ecoregion (Fig. During the last
at 1).
nine vascular plant taxa new science (including the one described herein) have been identified
years, to
some and more than 60
from seven records including regional disjuncts, taxa of
this area, as well as state
conservation concern (Allison 2001). With a total flora of over 420 species occurring within an area of ca.
Watch most United
125 ha (Alabama Water 2002), one of the botanically diverse areas in the eastern
is
it
(Allison 2001).
States
During 1999 survey of populations of the rare and endangered Xyris tennesseensis Krai in the
a field
and and
Ketona Glades, markedly different xyrid, shorter in stature smaller in vegetative floral features,
a
was found admixed with the former in a small, intermittent seep at the headwaters of a tributary to Alliga-
On
Aug 900
Creek (M. 7 1999). the date of the discovery, approximately flowering spikes of
tor Moffett
s.n.,
new
were emanating from approximately 200 clumps. Individuals of the putative xyrid
the novelty
tallied,
mixed and
showed fromX. across the population. This smaller different
consistent differences tennesseensis
known
from was once abundant. However, severe drought
thus only the type relatively
xyrid, locality,
far
during summers 1999 and 2000 decimated the population. The drastically reduced population size
the of
voucher
and climate have limited the collection of additional material.
fluctuating local
complex
mixed head-
The of this Xyris population, containing the novel xyrid, is a fen/seep at the
site
mapped Alabama
waters of Alligator Creek, within an area as "Alligator Glades West" by the Natural Heritage
by
Program (Alabama Natural Heritage Program 1999), and referred to as "Enchanted Glade" Allison (2001).
Glades West one 45 such comprising the Bibb County Ketona Glades and contains
Alligator of ca. sites
is
known new The Ketona Glades herbaceous communi-
the sole population of this taxon. are shallow-soiled,
Journal of the Botanical Research Institute of Texas 3(2)
-
Mg
relatively high levels of (> 1,100 ppm). The seep itself is very small, ca. 24 n
km N
Bend Cahaba Bibb County Alaban 33° Long. 87°
located 1.7 of Bulldog (Little River) in (Lat. 04';
i
owned
by
Ownership of has changed several times during our investigation currently
01'). this site It is
Forest Investment Associates, and previously by Great Eastern Timber Compan; and prior to that by U.S.
whom
we
Alliance/Coosa Pines Corporation, of are indebted to for access. Exte
all
known
County
Alligator Creek, and of the six glades (and their ecotones) in Bibb
have no
yielded other populations.
Common
Garden Experiment
common
The garden experiment developed from an attempt prevent the extinction of this in-
initially to
teresting new taxon. During the severe summer drought of 2000, and following the severe drought in late
known
summer
and of 1999, there was concern regarding the future viability of this sole population of
fall
mature was
August hedge spike
X. spathijolia. In 2000, as a against possible future extirpation, a fruiting
A
collected from each of the 13 surviving clumps sporting at least two such spikes. mature fruiting spike
also was collected from 13 of the surviving 21 flowering clumps of X. tennesseensis. Spikes were stored in
separate brown paper sacks in an unheated outdoor shed in Opelika, Lee County, Alabama.
In February 2001, seeds from each spike were sown onto a 60:40 mixture of Pro-Mix (Premier Horti-
cm
and grown
culture, Dorval, Canada) and sand in separate 15.2 diameter (6-inch) clay pots in a heated/
Auburn Ap-
evaporatively-cooled greenhouse the University Plant Science Research Center (PSRC).
at
proximately 50-100 seeds germinated in each pot by June. Plants were thinned to about 10 per pot during
471
new Alabama
from
and a xyrid
Krai Moffett, Xyris spathifolia,
removed from
was maintained. Seedlings pots (and
second and parental identity carefully
the year, their
Annual
hence experiment) were grown commingled in trays in a separate part of the greenhouse.
the
flat
PSRC During growing
greenhouse temperatures typically range from ca. 18.3-29.4°C, per records. the
bench
photon
(March photosynthetic irradiance level (adjusted for
season October), the average daily at
to
60% shade ranged from 3 mol m-2 d-1 15 mol m-2 d-1, on overcast and sunny days, respectively
to
cloth)
two weeks with 20-20-20 (N-P-K) during the
and were every liquid
(Elkins Wallace 2000). Plants fertilized
matured and reproduced
growing During the subsequent three years, the seedlings vegetatively,
season.
summer
clumps 30-40 ramets and 30-60 flowering spikes per pot by the of 2003.
generating of
ca.
summer we what began "rescue propagation" could provide data
During the of 2004, realized that as a
The
limited morphometric analysis of the principal characters distinguishing these syntopic xyrids.
for a
common "common
known grown from seed environment constituted a
parentage in a
3-year-old plants of
N
and
garden" experiment. Sample size was = 25; 12 pots of X. spathifolia 13 pots of X. tennesseensis.
new
The nine morphological characters selected for measurement are aspects of the taxon that, in the
The
and were charac-
most fromX. also easily quantifiable.
appeared obviously different tennesseensis,
field,
width, plant height, spike length, lateral sepal length, petal length, anther length,
ters are: leaf length, leaf
measurements were taken the widest longest) part of a
stamen length, and seed length. In cases, at (or
all
With plant structure
structure along the appropriate axis. regard to plant height, the longest or "tallest" for
maximum
some
although
each ramet was measured. This was usually a measure of scape length, in cases
was Flower length was measured from base of claw to blade
the structure of greatest length a leaf. petal
Stamens were measured from the point of basal fixation with the anther to the lowest point of basal
apex.
Data were not
measured major collected
adnation the Seeds were along the axis tip to tip).
to corolla. (i.e.,
on other important characters used in North American Xyris species classification because of the
several
two Excluded characters included: keel features of the lateral
high the taxa these characters.
similarity of for
and
sepal, position of the lateral sepal relative to the bracts (i.e., inserted/exserted), color texture of the leaf
sheath, and the presence/absence of a mealy (farinose) seed coating.
and randomly
Samples were generated by numbering reproductive ramets in a pot, then selecting
first all
from
by recorded
ramets from each Sample values each pot were created averaging the values
pot. for
five
from propagation did not
randomly ramets. Since most of the plants resulting the original
the selected
five
measurement
most ramets in
and produce summer/fall 2003, certain that selected for
flower seeds until is
it
mean
reproduction. Thus, each sample represented a
experiment were the result of asexual, vegetative
this
were developed
progeny clump. Samples for different characters
of the of a single distinct, field-identified
using approaches.
different
Measurements length and width were gathered from the four outermost leaves of each selected
of leaf
Measurements
were obtained using spikes from a selected ramet. of floral structures
ramet. Spike lengths
all
were recorded from open flower on each spike usually the case with Xyris that only one flower
the single is
(it
on
mature were each spike
measurements, capsules identified
opens each day per For seed length
spike). all
and were
One was randomly from each spike then seeds subjectively
and numbered. capsule selected five
chosen from each capsule measurement. Plant height measurements involved but a single value for each
for
made
and were using
Length measurements stamens, anthers, seed length a light
ramet. for petals, sepals,
microscope with micrometer.
a stage
means two were analyzed using the Student's
Differences in the nine character for the taxa statistically
improved
when assumptions and were not subsequently using either
normality
except data violated
t-test,
where non-parametric
square root or logarithmic transformations. This was the case involving seed size, the
Kolmogrov-Smirnov and Wilk-
was
Mann-Whitney was employed. Normality assessed using the
U-test
with
Homogeneity assumptions were evaluated using Levene's Levene's cor-
Shapiro of variance test,
tests.
Mann
Whitney-U
2 and
are expressed as eta values, for the
rection applied violations. Effect sizes for t-tests
to
was SPSS
Analysis
by an using Cohen's D. software utilized 16.0.
test effect size correlation (r y\) Statistical
and Shannon and Davenport
found (2000).
adhered procedures in Pallant (2001)
to
;
472
Journal of the Botanical Research Institute of Texas
3(2)
Review Herbarium
of Records
specimens from numerous and were and
Xyris regional, national herbaria reviewed annotated part
state, as of
this project. Taxa selected for the review process were either part of the X. "complex" (Krai 1978) or
difformis
known
occur with The complex
to syntopically X. tennesseensis. X, comprises X.
difformis difformh
and and
curtissii, difformis, floridana), X. tennesseensis, X. torta. Xyris jupacai not considered a
is r
complex, but does co-occur with few Only specimens
this X. tennesseensis at a locations. those
colli
and
Alabama, Georgia Tennessee range were examined. The purp
(the tri-state of X. tennesseensis)
investigation was to determine specimens of X. had been collected previously under
if spathifolia
known
name, thereby providing not only additional specimens for study, but also expanding the range of
new
Approximately 900 specimens and
the taxon. of X. X. jupicai, X. tennesseensis, X. torta were
difformis,
examined from AUA, DUKE, GH, Museum
vascular plant JSU JSU (Anniston
collections
at (Jacksonville),
of Natural History), MO, NY, US, TROY, UNAF, HALA, UNA, FLAS, GA, MICH, NCU, TENN, and VDB
at
BRIT. Herbarium acronyms Index Herbariorum (Holmgren
follow 2008).
Common
Garden
Experiment
common
grown
Analysis of morphological characters from greenhouse plants in a garden setting revealed
significant differences in all nine size-related traits. In all cases, measurements for X. tennesseensis specimens
were than
significantly larger those for X. (Table Significance values ranged from < 0.001
spathifolia to 0.03,
1).
39-93%
with each was by
effect sizes indicating that of the variance in character explained taxon
identity.
Table 2 provides an assessment of character differences between the two taxa based on vouchered
state
herbarium specimens and
collected material.
field-
Review Herbarium
Records
of
Review 900
approximately specimens andX. from
of of X. difformis, X. jupicai, X. tennesseensis torta 19 national,
and
regional state herbaria located only a single record fitting the concept of X. collected by James
spathifolia,
known new
R. Allison in 1993 from Alligator Glades West, the sole extant site of this taxon.
cm
Perennial, cespitose, 15-40(-50) tall, roots fibrous. Stems short, or present as slender, ascending, rhi-
on clump
zome-like bases innovations (result of burying of by seciment). Leaves ascending to erect, 15-30
cm
long, soft, sheaths often fully as long as blade or longer, gradually widening from keeled apex convex
to
proximally smooth, brown, upsheath with
base, multi-costate, pale tan to tints of red or pink, progressively
and
increasingly densely green margins narrowed
papillose, so pale, scarious, gradually blade
distally,
to
mm
most
(this often of its length infolding distal leaf of innovation); blade linear, mostly 1-2 wide, slightly
very margins smooth
to twisted, flattened, proximally to medially strongly papillose, toward apex or nearly
apex narrowed, incurved smooth;
so; excentrically acute, tip incrassate, blunt, surfaces densely pale-
its
and
granular-papillose interruptedly rugulose proximally, progressively smoother up-blade. Scape sheaths
than
shorter principal leaves, mostly open, short-bladed. Scapes erect or ascending, narrowly
linear,
ca. 1
mm
5-8
thick, twisted, pale green, proximally subterete with (mostly) papillate costae, the intervals smooth
or nearly so, distally sharply unequally angulate-ribbed, with up to 5(-7) costae making the angles, 2-3 most
raised, all densely papillate-tuberculate, the intervals sulcate to broadly concave, slightly to very papillose
mm
5-8
or papillose-rugulose in short lines. Spikes ovoid to ellipsoidal or lance-ovoid, long, blunt, several
mm
2-3
flowered, bracts in loosely imbricate, the proximal narrowly 2.5-3
flat spiral, sterile, ovate-triangular,
and
Krai Moffett, Xyri
Independent samples were used
nt. t-tests for
tr
iters. The Mann-Whitney U test was usee for the ninth chai
=
+
sks (*). Degrees-of-freedom values departing from 23 (N cance threshold of oc 0.05 was used. Effect
sizi
1
2
lann-Whitney U tests are given by eta and effect size correla
X.spathifolia tennesseensis
X.
= =
U)
(n (n
13) Test
Effect
Character (mean±S.E.) (mean±S.E.)
d.f. Sig. Size
*
±
±1.57
Leaf length (cm) 24.1 48.9 2.3 20.8 -8.87 <0.001 0.774
(mm) +
width ±0.16
Leaf
6.98 0.69 733
1.51
±
Plant height (cm) 27.5 3.54 48.6 ±3.83 23 -4.05
0.001
±042 *
(mm)
±0.67
Spike length
6.75 13.0 19.8 -7.93 <0.001 732
±
(mm)
Petal length 3.46 0.03 4.44 0.04 22.2 -17.5* <0.001
± ±
(mm)
Sepal length 4.27 0.06 4.77 0.07 23 -5.59 <0.001
(mm ±C02
Stamen
±0.06 -17.1*
length 2.14 15.7 <0.001 0.926
±
(mm)
Anther ±0.07
length
0.55 0.02 1.74 <0.001 0.927
(mm)
Seed
length ±0.01 ±0.01
0.52 0.55 22.7 -2.18
0.03 0.39
Comparison
Table 2. of selecte d morphological features in staxa.
Character State Xyrisspathifolio Xyris tennesseensis
x
(length width)
Leaf surfaces nooth
or finely papilla
blade edc
papillate,
?s
smool
looth, surfaces
densely
ridges
papillati
:,
x
sulcate deeply co ncave,
papillate
5-
Ovoid
ellipsoidal or lanceovoid,
tc
4.0-4.5 Tim
long, ciform, keel
la
pically
mm
Obovate ,ca.3.5mrr Obovate,
ca. 4.5
mm mm
2-2.4
ers 0.5-0.6 long, anthers 1.5-2
Ovoid c
Ellipsoid n, slightly farinos to broadly
ellipsoidal,
mm
long, keeled, the ones broadly obovate, 4.5-5 apex broadly rounded,
fertile entire, ag-
1
,
brown
ing with
erose, surface a lustrous rich a green, ovate granular dorsal area. Lateral sepals
free, equilateral, oblanceolate (viewed from side), ca. 4-4.5 long,; the thin keel entire proximally,
,
widening and
progressively shallowly ascending-lacerate blades obovate (measured
distally. tals di stinct,
mm
from claw
apex) staminodia
ca. 3.5 long, apically erose; bibrachiate, staminodial hairs pencillate,
mm
Capsule 2-2.5
slightly clavate. ellipsoid-cylindric, long, placentation seeds broadly
3-parietal; ellipsoid
mm
narrowly with 8-10
ovoid,
to 0.5 long, apiculate,
ca. ribs/side, slightly farinose.
Etymology.—The on morphology
epithet "spathifolia" is based a peculiar of lower leaves of innovations.
These margins and
are spathe-like, their conduplicate enfolding inner
leaves.
Journal of the Botanical Research Institute of Texas 3(2)
Leaf Sector of leaf midblade. d. Leaf sheath, e. Base of innova
Xyris spathifoiia (from the type), a. Habitat sketch, b. tip. t.
2.
Fig.
and
blade anther
lower (below) and middle (above) scape, g. Sector of distal part of of scape, h. Spike, i. Fertile bract, j. Lateral sepal, k. Petal (left),
m.
staminodium and branches Capsule, Seed.
(right).
style
I.
new
and from Alabama
Krai Moffett, Xyris spathifolia, a xyrid
the Research of Texas
Journal of Botanical Institute 3(2)
COMPLEX
KEY TO TENNESSEI SYMPATRIC XYRIDS, INCL. XYRIS DIFFORMIS
XYRIS
INSIS
combinations of these
or fimbriate, or various
Keel of laeral sepals usually firm, papil iliolate, in
Xvristorta
Keel of sepals scarious, lacerate
lateral
brown
een Xvris jupicai
Leaf sheaths or sheath base light gr straw-colored, or dull
2.
r
brown
red-brown.
Leaf sheaths or sheath base with re d, pink, or purple tints, or glossy or
2.
opaque
Seeds or mealy.
3.
mature bulbous
Base of plant
4.
cm smooth
30-70 sheaths and blade surfaces mostly or just slightly papillate
Plant in height; k;af
5.
somewhat and
along keels and edges; sca|oes with 2 ridges flattened wing-like distally, all papil-
difformis
not bulbous Xyris v
nt
much
somewhat widened
edges and smooth; scape
(except to distally;
for
ribs)
making wings smooth Xyris difformis
wider, or papillate v
much
widened
variously papillate or minutely scabrous; scapes not distally; ribs
DISCUSSION
known was
from once
As mentioned in the prefatory paragraph, this plant, thus far only the type locality,
abundant (over 200 clumps on the lower side of a small open seep). However, on our return to the site in
numbers chance
had reduced eliminating the additional
August drought (thus for
2000, severe drastically
We
voucher hope provide more vouchers once the population has recovered.
material). to
should be
The question of what rank to assign this novelty is intriguing. Certainly, careful attention
Of
known
given the plant sole location, as well as searching for in other calcareous fens of the area.
to at its it
North American
xyrids
particular interest the fact that, prior to this discovery, only Xyris tennesseensis of
is
new
known One morphology
was occupy would be tempted consider the a simple
fen-like habitats. to
to
mixing
extreme by were not the side-by-side of
anomaly, perhaps reaction habitat X. tennesseensis, for
a to it
on
which, distinguished the basis of several characters.
the two, nonetheless, are easily
between andX. were manifest primarily
Differences in several character states X. spathifolia tennesseensis
and
and wings, the of individual characters,
in terms of leaf scape surface features ridges, papillae), size
(i.e.,
was some specimens possess small
There tendency X. to
as well as the overall plant. also a for spathifolia
known
from North
rudimentary rhizomes, not other
ascending offshoots reminiscent of a feature
lateral
new
and
American xyrids. The differences exhibited by the taxon are of a nature degree that are consistent
with recognized genus (Krai 1966; Krai 2000).
species status distinctions for this
CONSERVATION CONSIDERATIONS
and
Considering the documented rarity of X. association with similarity to X. tennesseensis,
spathifolia, its
known made
argument can be
and the specific threats associated with single extant site, a strong for a
its
pine
"high" conservation ranking. This sole isolated site is located within a fire-suppressed loblolly planta-
with woody encroachment. The overstocked plantings along (and within) the inter-
tion severe tree/shrub
reducing groundwater (Jackson
mittent stream course supplying the fen are capable of drastically levels et
owned no
with conservation
2005). Moreover, this lacks formal legal protection is privately
site (i.e., it
al.
and
Thus would seem requirements both extreme
easements/covenants in to satisfy the of rarity
place).
it
new
and from Alabama 477
Krai Moffett, Xyris spathifolia, a xyrid
necessary imperiled ranking both and Alabama using
threat to justify a critically globally in (Gl/Sl), the
NatureServe
(2008) system.
North America The
in (north of Mexico). currently recognized Xyris species of greatest conservation concern
known
X. from approximately 25 in three (AL, GA, and TN) with NatureServe
is tennesseensis, sites states a
global ranking of imperiled (G2). Xyris tennessensis also has status and receives protection under the federal
Endangered Species Act of 1973, under law in Georgia through the Georgia Wildflower Preservation
state
Act of 1973 (Georgia Dept. of Natural Resources 2008), and under law in Tennessee through the Rare
state
now
Plant Protection and Conservation Act of 1985 (Crabtree 2008). Conversely, as X. only
spathifolia is
new
being recognized as a species, enjoys no legal protections at either the federal or state level. Further
it
contributing to this precarious situation the lack of any state laws protecting rare plants in Alabama.
is
The some
conservation situation involving X. obviously Currently, there living
spathifolia is dire. is
common
material remaining from the garden study that will be safeguarded Georgia Plant Conserva-
at
member
tion Alliance (GPCA) institutions and the Auburn University Donald E. Davis Arboretum. Visits
from West
to obtain additional X. spathifolia seed the Alligator Glades in order to bolster the existing
site,
made made
work
be August/September be
ex situ collections, will in of this year (2009). Efforts will also to
new
cooperatively with the property owners of the Alligator Glades West Forest Investment Associates,
site,
manage
both
to better the for the benefit of xyrids.
site
The wish and
authors to express their gratitude to the U.S. Alliance/Coosa Pines Corporation, the Great
Company
Eastern Timber for their access to the and to Jim Allison, Georgia Department of Natural
site,
known
Resources, Natural Heritage Program, his 1998 tour of Bibb County Glade containing
for all sites
Two anonymous
X. including the research. reviewers provided constructive and
tennesseensis, for this
site
We
wish acknowledge Hansen, John Freeman Herbarium,
helpful reviews. also to Curtis Curator, D. for
with
his assistance loan material.
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