DISTRIBUTION AND TAXONOMY OF SYMPHYOTRICHUM SERICEUM AND S. PRATENSE (ASTERACEAE: ASTEREAE)

2008·14.7 MB·English

by  Ronald L Jones

AND TAXONOMY
SYMPHYOTRICHUM
OF SERICEUM
DISTRIBUTION
AND
PRATENSE (ASTERACEAE: ASTEREAE)
S.
L CTheoWitsell
Ronald Jones
of
Dept. Biological Sciences
1500 Tower
Building
323
Eastern Kentucky University Center Street
:hmond Kentucky USA. Arkansas 7220
40475, Rock, U.S.A.
Little
1,
t
Nesom
Guy L
h
2925
USA
Fort Worth, Texas 76109,
guynesoim@sbcglob( im.com.
http://guynesc
il.net;
ABSTRACT
Nesom Nesom
and two
Symphyotrichum sericeum (Vent.) pratense (Raf.) are closely related taxa of central
S.
&
and eastern United In most treatments they have been maintained as distinct species Correll
States.
(e.g.,
When
Nesom
Johnston 1970, Cronquist 1980, Jones 1990, 1994, Brouillet et 2006). the taxa are considered
al.
&
Wunderlin Hansen
to be conspecific (see 2004), pratense treated as sericeum var. microphyllum (DC.)
5. is S.
& &
known many
Wunderlin Hansen. Symphyotrichum was years Aster
B.F. pratense for as phyllolepis Torr.
from Texas North Dakota
Symphyotrichum
A. Gray. sericeum generally distributed in the central to
states,
is
and southern Canada, western Michigan. Symphyotrichum pratense largely concentrated in eastern Texas
to is
—
and western Louisiana. Populations of plants in this complex that are disjunct further eastward to Florida,
—
Virginia, and Kentucky are somewhat intermediate in phyllary morphology and have been variously treated
number
and widely
as sericeum, pratense, or sericeum var microphyllus, a of states treat these often
S. S. S.
Chromosome
need both
scattered populations as counts also clarification, as ploidy levels (2n
state-rarities.
= 10 and In = 20) have been published for both taxa (Brouillet et 2006). The objective of this paper is to
al.
update information on complex, geographical point out distinguishing
available this clarify distributions,
chromosome and summarize
and review information,
features, identify typical habitats associates, available
the state-rarity status of the taxa.
732 Journal of the Botanical Research Institute of Texas 2(1)
The present study provides detailed view of the geographic distribution of Symphyotrichum sericeum
a
MO,
BRIT-SMU, EKY, GA, LSU,
from
and based primarily on study of herbarium specimens
pratense, a
S.
NCU, NLU, TENN, TEX-LL, UNC, VDB, and Maps augmented by records from various published
VPI. are
A
chromosome numbers was
The on and also reviewed.
associates,
sources. available literature habitats,
new chromosome from Kentucky population based on mitotic counts from root tip squashes
report
a
is
from germinating achenes. The key ased on a detailed examination of morphological characteristics of
is
from two
herbarium specimens across the ranges of the taxa.
SYMPHYOTRICHUM SERICEUM
from Arkansas and
and Habitat.—The primary Symphyotrichum sericeum
Distribution distribution of
is
Oklahoma southern Canada western Michigan and Indiana, with disjunct populations in central
to to
sandy
dunes,
Texas Over the larger part of range, sericeum occurs in a variety of habitats, e.g.,
(Fig. its S.
1).
open
outcrop— with
woods, sandstone glades, over granite but typically associated seasonally dry,
glades,
on Edwards where
semi-open Symphyotrichum sericeum in Texas mostly occurs the Plateau,
habitat. it
to
An
grows on limestone commonly on open, rocky slopes and roadbanks. early collection supposedly
hills,
Edwards
made the (Harris Co.: Lindheimer BRIT) similar in every respect to Plateau plants
far to east 78, is
number
and may be mislabeled. Swink and Wilhelm (1994) a of associates of this species in Illinois,
list
and
including Amorpha canescens, Schizachyrium scoparium, and Bouteloua curtipendula in dry hill prairies,
Lake
Anemone and cernua in sand barrens near
Spiranthes sites
cylindrica, Liatris aspera, Liatris cylindracea,
and sometimes under
on
Michigan. In Wisconsin occurs dry prairie hillsides, outcrops, bluffs,
at sites
it
open dominated by Schizachyrium scoparium, with
oaks, jack pine, or red cedar, but usually in the in habitats
&
Manitoba
and (Cochrane 2000). In the
Dalea purpurea, eupatorioides
Asclepias Brickellia litis
viridiflora,
species occurs in remnant tall-grass prairie sites and in openings in Quercus macrocarpa/Populus tremuloides
&
Hamel
woodlands
(Foster 2006).
The primarily associated with the Central Lowlands Physiographic Province in the U.S., but
species
is
A
and Symphyotrichum
also occurs in the Ozark Plateau Province of Arkansas Missouri. recent collection of
it
sericeum from open shale barrens on a southwest-facing slope in central Arkansas, is apparently the first
record from the Ouachita Mountains Province. This disjunct from the nearest populations about 155
site is
km
on Ozark Voucher: Garland Co.: Ouachita Mountains, Ouachita National
the northeast the Plateau.
to
and Walnut Creek
on upper above
Forest, steep S-facing shale barrens (Mazarn Formation) slope, east of
750
near point which flows into Lake Ouachita, Crystal Springs 7.5' quadrangle, steep glades, elev
at
it
A
(ANHC,BRIT, UARK).
hundreds of plants in high quality shale barrens, 29 Sep 2006, Witsell 06-471
ft,
km
above
northwest
second population was subsequently found in similar habitat of the
1.9 site.
Chromosome Numbers.—
There are about a dozen published diploid counts for Symphyotrichum seri-
& &
Semple
Semple
ceum, these mostly from the northern portions of range (Jones 1980; Brouillet 1980;
its
Chmielewski Semple 1989; Semple 2002), with the most southerly count from Izard Co., Ar-
1987; et et
al. al.
kansas (Sherif 1983). There apparently only a single report of a tetraploid count (Love 1982) for S. seri-
et is
al.
same comm.).
from Semple,
ceum, count from Canada; there are also diploid counts this vicinity pers.
this
(J.
Nesom synonym
Taxonomy.—
Symphyotrichum lucayanum as a of
Brouillet (2006) treated (Britt.)
et
al.
more Nesom, based on
sericeum, but lucayanum here considered to be closely related to S. concolor (L.)
S. 5. is
The
and morphology and geographical proximity.
in capitulescence phyllary their closer
their similarities
Nesom
was by
widespread the southeastern U.S.A. Symphyotrichum lucayanum treated (1994) as a
in
latter
is
based on very loosely racemiform capitulescence with interspersed leaves only slightly
distinct species,
its
more
reduced or not from the proximal cauline, different from the densely congested, bracteate capit-
at all
ulescence of Turner (1982) treated the taxon as a synonym of Aster concolor L., and the type of
concolor.
S.
&
was by 1974
lucayanum Uillspaugh 2448, NY!) annotated W.T. Gillis in as A. concolor.
Aster (Britton
Britt.
State-Rarity.—Symphyotrichum sericeum currently ranked as S2 (Threatened or Rare) in Arkansas,
is
Canada
Threatened
Indiana, Michigan, and North Dakota (NatureServe 2008). listed as Nationally in
is
Symphyotrichum sericeum and pratense
Jones et al„ Distribution of S.
from
Sym d are from vouchered observations; dotted circles are literature
Distribution of circles
Fig. 1 i
.
Journal of the Botanical Research Institute of Texas 2(1)
by and NatureSer
Brouillet (2006)
et
ir al.
—
Distribution and Habitat. The densest distribution of Symphyotrichum pratense in Texas, Louisiana, and
is
—
southern Arkansas scattered, disjunct clusters of populations occur eastward over a wide geographic range
and
in a variety of physiographic provinces Symphyotrichumpratense in Texas characteristically occurs
(Fig.
2).
in sandy soil (sand, sandy loam, sandy clay, silty clay, silty clay-loam), being largely restricted to the follow-
Oak Woods
ing natural Piney Woods, and Gulf Coast and Marshes, and Blackland
regions: Prairie, Prairie
Within Texas. Dallas 12032
Prairie. these regions, less frequent in blackland prairie: Co.: Lundell
is e.g.,
it
&
who name
(LL, SMU). Shinners recognized the legitimacy of the Rafinesque ahead of the Torrey
(1950),
Gray name, and showy open oak woods and
described this species as frequent plant of transition-belt
"a
and and
prairies thoughout east Texas ." In Texas, pratense also occurs in longleaf loblolly pine areas in
S.
. .
and been from and
coastal prairie grassland, has collected roadsides, clearings, fencerows.
fields,
it
and
In Louisiana the plants occur in pine flatwood blackland prairie, chalk calcareous clays,
sites, hills,
A
on
as well as along dry roadsides. blackland prairie locality for Symphyotrichum pratense is the "Kieffer
Winn
Brown 8220 (SMU) and from same (LSU Herbarium
Prairie:" Par.: five other collections the locality
Online Database 2008). At the Kieffer Prairie pratense grows with associates such as Schizachyrium sco-
5.
and
parium, Andropogon gerardii, Sorghastrum nutans, Echinacea pallida, Oligoneuron rigidum, Vernoniamissurica
(USDA
Forest Service 2008).
open
In the Gulf Coastal Plain of Arkansas, typical habitat for Symphyotrichum pratense saline
is
—
barrens treeless openings in Pinus taeda/Quercus flatwoods with clay soils containing high levels of
similis
who
sodium and/or magnesium. Eric Sundell, discovered the species in Arkansas the Warren Prairie
at
first
number
(Sundell 1983), noted that the plants occurred with prickly pear and dwarf palmetto and that a of
other rare species were associated with these including Geocarpon minimum and Schoenolirion wrightil
sites,
USDA
NRCS
The (USDA, and Newton Arkansas
Plants website 2008) Izard counties in for pratense,
lists 5.
but these records from northern Arkansas are based on collections of sericeum.
5.
Eastward Alabama, Florida, Georgia, Kentucky, Mississippi, Tennessee, and Virginia), Symphyotrichum
(to
and
pratense occurs mostly in calcareous habitats, chalk barrens, cedar glades, limestone outcrops. Krai
e.g.,
(1981) reported on the species Coastal Plain in Alabama (Sumter Co.) and Florida (Gadsden Co.) and
at sites
noted that the plants in Alabama were found in blackland prairie patches and that those in Florida were
The was from
the coast. species subsequently discovered in Decatur Co., Georgia, just across the state line
&
Gadsden on Decatur 80099
Co., in calcareous glades a Co.: Godfrey Gholson (GA). In Mississippi
bluff:
McCook, The
the species occurs in association with calcareous chalky outcrops pers. comm.). central
(L.
Alabama and Barone The most
Mississippi populations are located in the Black Belt prairie lands (see 2005).
Rim
Alabama Highland
northerly populations in occur in limestone prairie barrens within the province,
many
with
along other rare species, including Dalea Leavenworthia alabamica, Cypripedium can-
gattingeri,
and magnicamporum (Webb
didum, Eriogonum longifolium var. harperi, Schoenolirion croceum, Spiranthes et
al.
1997).
At most northerly range limits in Kentucky, Symphyotrichum pratense found in glades or barrens
its is
Low
Rim
habitats of the Interior Plateaus (chiefly Highland sites) with Juniperus virginiana and Quercus
woody
marilandica the dominants and with Andropogon Schizachyrium scoparium, Sorghastrum
as
gerardii,
and These
nutans, Sporobolus compositus, as the conspicuous grasses. habitats often contain
S. vaginiflorus
a variety of other rare or infrequent plants, such as Cypripedium candidum, Echinacea pallida, Liatris aspera,
and
Lithospermum Dalea Dalea
Liatris cylindracea, canescens, Silphium pinnatifidum, Candida, purpurea, Phys-
ostegia virginiana (Cranfill 1991; Kentucky State Nature Preserves Commission 2008). The barrens sites in
Rim
Tennessee (Highland and Appalachian Plateau and in southwestern Virginia (Valley and Ridge)
sites)
Jones et Distribution of Symphyotrichum sericeum and S. pratense
al.,
dotted from
Distribution of Symphyotrichum pratense. Solid circles are from vouchered observations; circles are literature records.
2.
Fig.
number (DeSelm Ludwig
are very similar to the Kentucky sites and also contain a of very rare species 1990;
1999; Tennessee Natural Heritage Program 2008). In northern Georgia the plants occur at both Appalachian
and and Ridge comm.). In the Coosa watershed of Georgia,
Plateau Valley Patrick, pers. rive
at sites (T.
:
with habi include
other iated this at Asclepias hirtella,
pra,
S.
Hypericum
Buchneraamericana, Dalea Echinacea urn dolabrijorme,
gattingeri, pallida,
\tra\is, I
Depa
and magn: (Georgia
sphaerocarpum, squarrosa, Spiranthes
Liatris
7i
2007).
Recent investigations of dolomite and limestor n southwestern Virginia have disc
-
by Ludwig subsequently
Symphyotrichum reported treated
several populations of pratense initially (1999),
We
by Weakley and Virginia Botanical Associates (2008). have studied the
Brouillet (2006), (2007),
et
al.
W
km
following vouchers: Russell Co.: E of Carterton, one-acre barren at top of SW-facing slope on end
1
May
20 1996 Wie-
of a short ridge, dense grass cover with dolomitic limestone cobbles, [not yet in flower],
km
hardwood with
boldt 9415 (VPI); river knob 1 E of Carterton, top of SW-facing slope, substrate cobbly
and
2100 dominant with aspera Andropogon scattered over
dolomitic limestone, species Liatris gerardii,
(?) ft,
most of one-acre barren, 17 Sep 1996, Wieboldt 9605 (VDB, VPI); E side of Mill Creek where cuts through
it
km N
between Clinch River and Reeds of Jessees Mill, SW-facing limestone hillside in
ridge Valley, ca. 1.9
3082
2040 20 Sep Ludwig
open grassland dominated by Schizachyrium scoparium, ca. plants, 11 1996,
ft,
Wise Fleming 14122 (GMUF). Ludwig (1999) noted that this species has been found at six Russell
(VPI). Co.:
,
736
Journal of the Botanical Research of Texas
Institute
2(1)
Chromosome Numbers.—
The 2n=20
first report of the tetraploid level of for Symphyotrichum pratense
who
was from Gonzales Texas, by Semple and noted count had been
Co., Brouillet (1980), that a diploid
made
earlier for the species, but that report was unvouchered and part of a 1945 embryological study by
German
anatomists. Semple and Chmielewski published counts from Grimes and
(1987) diploid plants
for
Walker counties Texas and count Milam Two Semple
in a tetraploid for plants in Co., Texas. years later
et.
we
(1989), reported a diploid count of 2n=10 for plants from Gadsden Co., Florida. In addition, report
al.
KY
a previously unpublished 2n=20 count for pratense: Kentucky. Hardin Co.: cedar glade off 2762, 6
S.
Nov
5457
1987, R.L.Jones (EKY).
—
Taxonomy. main
In the part of the range of Symphyotrichum the plants have phyl-
pratense, typically
and
lary surfaces mostly glabrous strongly contrasting with the spreading- margins. Phyllaries of the
ciliate
Virginia plants are unusual, having densely sericeous surfaces, with or without strongly margins, but
ciliate
resemble typical pratense of Texas and Louisiana in the proximal indurate portion of the phyllary being
S.
relatively short, the distal leafy portion being relatively broad and long, and the overall phyllary length about
Some
1.5 cm. Their geographic position also obviously suggests that they are part of pratense. plants from
S.
Roane
Tennessee are similar in their phyllary features Co.: Morton 1307, SMU).
(e.g.,
The
description of Aster montanus Nutt. seems to refer to Symphyotrichum pratense; Nuttall noted that
it
was
"nearly allied to the preceding [Aster sericeus], but distinct." Torrey and Gray (in N. Amer.) treated
Fl.
known
They
noted was from and North
as A. sericeus also that the species "Tennessee Carolina
var.
it
p.
On
near the mountains." 1816 he crossed from Tennessee and went on
Nuttall's Asheville, N.C.,
trip, to
name
to Rutherfordton and Morganton (Graustein 1967). Gray Synop. N. Amer. formalized the
(in Fl. at
)
varietal rank, as Aster sericeus var. montanus (Nutt.) Gray, noting that the involucre "sometimes glabrate
is
An
and
villose-ciliate; approaching the next species [A. phyllolepis]" image of the holotype of A. montanus
cm much
was obtained from PH, and an examination indicates that the involucral widths are about 2 wide,
we
than and name synonomy
larger typical sericeum, therefore place this in the of pratense.
5. S.
known
Today
nor North Gray
neither sericeum pratense occur in Carolina. N. Amer.)
S. S. is to (in Fl.
North and
listed Carolina as included in the range of A. Synop. N. Amer.), he
sericeus var. later (in Fl.
p,
specified Buncombe County as the of the collection. The specimen upon which Gray apparently based
site
comment
was NY, and an image was The from two
his located at obtained. sheet bears three plants
dif-
areas—
two from Minnesota and was from
ferent are identified as Aster while the other collected
sericeus,
"Buncombe, North and
specimen
Carolina, Gibbes" identified as "A. sericeus (montanus Nutt.)." This latter
p.
known
heads and
exhibits the large of pratense, here assigned to that taxon; represents the only record
5. is
it
from North been and
of the species Carolina. pratense has not subsequently rediscovered in the can
state
S.
be assumed
be
extirpated
to there.
monk
anus Nutt., Gen. N. A]ner. Pi. 2:156. 1818 (non A. inus All. 1785).
Aster sericeus var.
No
n
nnessee. other collection c Nuttall September to early Octob< 1816, fide Graustei 1967], annotate
Lata, [T. s.n., >r
When
these disjunct populations of Symphyotrichum pratense were discovered in eastern especially
first U.S.,
more
at the northerly sites in Alabama, Tennessee, and Kentucky, they were often identified as sericeum.
5.
We
They now
such confirm examined
are listed as in several state natural heritage databases. speci-
still all
mens
from Alabama, Florida, Georgia, Kentucky, Mississippi, North Carolina, Tennessee, and Virginia as
—
main
State-Rarity. Symphyotrichum pratense generally rare outside range in Texas and Louisiana
is its
—
it is currently considered Threatened (S2) in Arkansas, Special Concern (S3) in Kentucky, and SI (critically
imperiled in Alabama, Georgia, Mississippi, Tennessee, and Virginia (NatureServe 2008). Although there
) is
known
only one county occurrence only where
of in Florida (the state it still is treated as a variety of S. seri-
among
ceum, pratense currently not listed that rare species (Florida Natural Areas Inventory 2008).
S. is state's
Jones et Distribution of Symphyotrichum sericeum and pratense
al., S.
Taxa.—
Morphological Criteria for Distinguishing the Our examination specimens from th
of
much
two
out of the ranges of the taxa indicates that they can be reliably distinguished as follows:
1/4-1/3(-1/2) the
total phyllary length, jsually distinctly shorter
i
<
middle
portion; phyllaries mostly 7
te
mm Omm
mm)
< '
wide; involucral height mostly (7-11 high
3)
I
Symphyotrich
ui
sericeous
itrigose (rarely
he
phyllary length,
total
mm
> >
llabrate portion; middle phyllaries mostly 8 long and
2.5
Symphyotrichum and and They
pratense sericeum are distinct species of central eastern U.S. are largely
S. al-
common
and
lopatric in distribution, occur sympatrically only in Texas, where pratense and sericeum
S. is S.
Symphyotrichum with provinces—
pratense associated range physiographic
rare. a of chiefly Coastal
is is
it
Low
Plain in distribution, but its range extends to the Interior Plateaus, the Appalachian Plateau, and the
and
Valley Ridge. There an historical record from the Blue Ridge of North Carolina. Symphyotrichum
is
seri-
ceum
with Lowlands and Ozark and
is largely associated the Central Province the Plateau, only sporadically
into adjacent provinces to the south, north, and west. Disjunct populations and population systems
are
a
prominent some
feature of the biology of both taxa. There intermediacy in phyllary pubescence in the
is
easternmost disjunct populations, but these features could be interpreted as resulting from local genetic
drift
in populations far removed from the main range of the species, and there no evidence of any significant
is
gene interchange between the taxa. The available evidence indicates that sericeum consists of diploid
5.
populations (with the exception of one anomalous report) and that pratense contains populations both
S. at
common
much
ploidy levels. Symphyotrichum sericeum is generally throughout of range, considered rare
its
only in the states at the eastern and southern periphery of range (Michigan, Indiana, and Arkansas), and
its
Nationally Threatened Canada. Outside Texas and and
is in of Louisiana, pratense a rare plant con-
5. is is
sidered critically imperiled in several states (Alabama, Georgia, Mississippi, Tennessee, and Virginia). The
—
been some
identity of these disjunct eastern populations has the source of confusion in the past they have
been variously treated by the different states as S. pratense or S. sericeum, and this latter name continues to
be used by some Our
eastern states for their rare species study concludes that specimens examined
lists. all
from
populations in Alabama, Florida, Georgia, Kentucky, Mississippi, North Carolina, Tennessee, and
We
MO, TENN, TEX-LL
and
are grateful to staff at for help during visits there and to the curators and
staff
Tom
we
of all herbaria that provided loans. In particular, thank Wieboldt for a loan of specimens from VPI,
Townsend
Johnny
(Natural Heritage Program, Virginia Dept. of Conservation and Recreation) information
for
GMUF
on Virginia Andrea Weeks an image Wise County
collections, at for of the (Virginia) collection of
PH
Symphyotrichum Alina an image
pratense, Freire-Fierro of for of the holotype of Aster montanus, Jacquelyn
NY
Thomas
Kallunki, Zanoni, and Lucy Klebieko of for providing a virtual herbarium loan of the speci-
men
from North Carolina, and John Pruski (MO) help with obtaining Brent Baker (UARK)
for literature.
provided distribution data for specimens compiled by the Arkansas Vascular Flora Deborah White
Project,
McCook
provided from Kentucky Commission
data the State Nature Preserves database, Lucile provided
Wood
information on Mississippi populations, Emily and Walter Kittredge specimen searches GH,
for
at
Wendy
and Zomlefer and David Giannasi information on Georgia we thank John
for records. In addition,
Semple chromosome
on
for his assistance in the gathering of information counts.
Journal of the Botanical Research Institute of Texas 2(1)
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