A NEW NARROWLY ENDEMIC SPECIES OF CLEMATIS (RANUNCULACEAE: SUBGENUS VIORNA) FROM NORTHEASTERN TEXAS

2006·7.4 MB·English

by  Dwayne Estes

NEW
NARROWLY
A
ENDEMIC OF
CLEMATIS
SPECIES
(RANUNCULACEAE: SUBGENUS
VIORNA)
FROM
NORTHEASTERN
TEXAS
Dwayne
Estes
University of Tennessee Herbarium (TENN)
Department and
of Ecology Evolutionary Biology
University of Tennessee
Knoxville, Tennessee 37996,
U.S.A.
[email protected]
ABSTRACT
new
Clematis carrizoeiisis, a narrowly endemic species of subgenus Viorna, described from the
is
Carrizo Sands of northeastern Texas, This species belongs to a complex of similar species character-
ized by glaucous and glabrous abaxial leaf surfaces and stems. Four additional species comprise
this
complex: C.addisonii, C.glaucophyllaX-texensis, and C. versicolor Clematis carrizoensis morpho-
is
most
logically similar to the scarlet sepaled C. Eexenszsand the purplish-red to bluish-lavender sepaled
C
versicolor. It differs from those two species in having yellowish-cream and lightly lilac-tinged se-
m
pals. From. C. addisonii dnd C. glaucophylla. C. carrizoensiscV\{krs sep-dl color and having thicker
iri
and more reticulate leaves. All five species of the complex are allopatnc and occupy somewhat
dif-
ferent habitat types in different physiographic provinces. Further discussion of their morphological
geographic and
differences, distribution, habitat preferences provided.
is
RESUMEN
um
Se describe Clematis carrizoensis, nueva especies del subgenero Viorna, endemica de Carrizo Sands
en el noreste de Texas. Fsta especie pertenece a un complejo de especies similares caracterizadas por
C
tener los tallos y el enves glaucos y glabros. El complejo tiene otras cuatro especies; addisonii, C.
glaucophylla, C. texensis, y C. versicolor Clematis carrizoensis es lamas similar morfologicamente a
C
texensisde sepaios escarlata y C. versicolor de sepalos que van del rojo purpura al lavanda azulado.
C
Difiere de cstas dos especies por tener los sepalos amarillo crema ligeramente tenidos de De
lila.
C
addisomi
y C. glaucophylla, se diferencia carrizoensis por color de los sepalos por tener las
el
y
mas mas
hojas grucsas y reticuladas. Las cinco especies del complejo son alopatricas y ocupan
diferentes habitats en provincias fisiograficas diferentes. Se ofrece una discusion sobre sus diferencias
morfologicas, distribucion geografica, preferencias de habitat.
y
In North America, 18 species of Clematis (Ranunculaceae) belong the subge-
to
nus Viorna Of
(Pringle 1997). eight currently recognized species were
tliese,
included in the formerly recognized Clematissection Viorna subsection Vwrnae
C
(Erickson 1943; Dennis 1976; Krai 1987): addisonii Britton, glaucophylla
C.
&
C C C C
Small,
morejieldii Krai, pitcheri Torr. A. Gray, reticulata Walter,
C C
L
and
texensis Buckley, versicolor Small, viorna These species are peren-
nial vines characterized by relatively large (1-3 cm) urceolate flowers with thick
leathery sepals that are mostly arranged in solitary or few-flowered cymes borne
SIDA 65 -77, 2006
22(1):
BRIT.ORG/SIDA 22(1)
66
on axillary peduncles subtended by leafy bracts (Dennis 1976). These taxa can
The
be delnieated into two groups based on leaf vestiture (Dennis 1976). first
C C
and viorna have
group including morcficldii, C. pilchcru C. reticulata^ all
and The second
variously pubescent abaxial leaf surfaces steins. species of the
and
group, characterized by gh:ibrous and glaucous abaxial leaf surlaces steins,
These
species
include C.addisonii, C.gJaucophylla, C. tcxc n sis, iind C. versicolor.
form a complex here referred to as the C.glaucophylla complex.
rom
The ucophyJla complex can be distinguished each
species of the C.gla
I
com-
other by relatively few qualitative morphological characteristics. Often, a
morphology and must
bination of features, including habitat, distribution, be
used to identify taxa. Several structures including the cauclex, roots, inflores-
cences, and achenes offer or no taxonomic value in separating most spe-
little
complex Dennis The most taxonomically use-
cies of the (Ericl<son 1943; 1976).
and
ful traits are leaf texture, degree of leaf vein reticulation, sepal color,
and
although even these characters exhibit considerable variation intergrada-
when
tion (Erickson 1943; Dennis 1976). For instance, leaf thickness is useful
Dennis noted such age
extremes are exhibited, but (1976) that factors as leaf
make
and environmental conditions often a difficult character to assess. Simi-
it
character found extremes
larly degree of vein reticulation is a useful vv^hen in its
when continuum between
but can be confounding trying to evaluate the ex-
it
tremes (Dennis brickson (1943) concurred, noting that while reticubuc
1976).
venation valuable taxonomic character, not often possible to distin-
is a "it is
Dennis considered
guish betw^een degrees of reticulation consistently." (1976)
complex;
sepal color to be important for distinguishing species of the for ex-
C
from
ample thin-leaved specimens of versico/orcan only be distinguished C.
glaucophylla by sepal color Other characteristics, including degree of leaf dis-
and stamen only generally
section, leaflet shape, flower shape, vestiture, are
Whil
useful distinguishing species and are apparently never diagnostic. e
for
Cg/aucophy complex may mor-
the species of the be difficuh to differentiate
/la
phologically members of the complex exhibit specific physiographic pref-
all
erences (Dennis 1976) and have non-ovedapping ranges (Fig.
1).
and Cversico/orare completely allopatric with the former
C/c?i7a trsfexensis
restricted to the Edward Plateau of Texas and the latter confined to the Inte~
s
lighlands (Arkansas, Missouri, Oklahoma) and Interior Low^ PEiteaus (Ala-
-tor
1 I
and
bama, Kentucky, Tennessee). They differ consistently in flower color gen-
erally in leaf dissection and leaflet shape. Both species usually have relatively
thick and conspicuously reticulate leaves. Erickson (1943) called attention to
between
possible intermediate populations occurring in the region the Interior
Highlands and the Edw^ards Plateau noting that some specimens from this re-
gion have been difficult to assign to a particular species. Erickson arbitrarily
specimens from southwestern Arkansas and southeast-
referred c[uestionable
Oklahoma and specimens from northeastern Texas (Smith
ern
to C. vcr.sico/or
—
I . ' r . ^ .
NEW FROM
ESTES, A SPECIES OF CLEMATIS TEXAS 67
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—
—
—
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&
— -^ 1 -.,.Jv4 Ci
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-C^T- t 'v. -i.. <" > /"
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-—s,-/ /' V ' *, V .yV r- '^^^^*^--sS--1- -»LH * J- * -f- T^TV->- "-^^^r^""*^. -.
- > Or,.y v^ <-.yj / /^<-. /- S fr ' \ 3 — V.,-; ^ *^^-w.
I P—r>^^i ^ J -. siv 'V.N / t-4 .J-_ __ -r.^?
v^ -X'\ A-i!
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—
4: ^
* - i.-t % V-* J T-
b'?-^ v' I
O- X
J. „,? /.
J * % ^r n -^ >fLF - -_--/ r' ^
-i r ->^>_^_i^. -,,-^^ ( ^T -r\.j ^^t-4— -r < ^ Jr L/' ; <^.-- -s: V
r- J---I /i' ,< ^-E
_..t-*-^ ^._
-\ ^ *~
if r-. '^^-n/
[ j I t'- ..i. y >^.
? ;i r "^-H X>-^:- .' '*.-,-^,
\. .-4. r- x: V.
r ^_ - -^^ ,/
:^<> ^\>^
/T
v"
b-/>.
v.
.y ^
l.,„J^T-r-^
-',^,.lJO
r' -Ci-
-^.
- y l^x T-n_^ Je ' u. ^ x^lr.,^-^
.<
-- ^>'<T'1 '/
f ^ S -. V' i-i' • ^i tf . 1 -Hi ,vr^
r ^ -t
V y
1-
,
Legend
'I -'
.;-<
^
t ^ r" '\ ^
r ^
>
r i - ^-P -^
-4- Clematis
^ spp.
™>-.
—
^
L >^
C. addisonii
i,-,..
J 4
t
C
carrizoensis
L
C. glaucophyila
C. (exensis
C. versicolor
400
Kilometers
1
J. Geographic ranges of the five species of the C/emot/5g/aufo/7/]y/to complex. (Adapted from Dennis 1976)
Fig
C
County) to tcxensis. Dennis (1976) contended that the Texas specimens were
C
not because the sepals were white pale lavender rather than the
texeiisis to
Dennis
bright red characteristic of that species. Interestingly, (1976) referred
from
the Texas plants to versicolor in spite of the fact that they also differed
C.
and and occurred physiographic
that species in sepal color habitat in a different
km C
known
region 200 from nearest versicolor population. Additional
ca. tlie
study herbarium specimens from region coupled with work has
of this field
C
revealed that the Texas populations previously referred to versicoloractually
new
represent species described below.
a
nov
Clematis carrizoensis D. Estes, sp. (Figs. 2, 3, 4B). Type: U.S.A. Thxas; Smith Co.; 1.5
NW
ETiL of Linclalc, sandy soil, vine growing along fence near roadside, 15 May 194*^)J.r Hcnncn
SMU).
408, consists of 2 sheets (llOLOTYPH:
A
Clematide vcrsieolore sepalis e lilacinis flavidis-cremeis, loliis plerLunque dissectioribus, foliolis
saepiuseule emarginatis ad apices profnndius basibus
eorclatis dilfert.
m
woody
Perennial trailing or scandent vines to 3 long, from a caudex 'bearing
numerous smooth fleshy apparently unbranched Stems stout proximally,
roots.
and
slightly flexuous distally, 6 angled, 12 ribbed, glabrous glaucous, reddish-
brown
to pale brown. Leaves oppositely decussate, imparipinnate to pinnate-
68 BRIT.ORG/SI0A 22(1)
HE"?3ARiUM
lEXAS
DAtlAS.
^
t
V^
^_b___ \ ^^ ^^^ \ ^J.A^^^'
THE UNiVfiHSlTV Of TCNNESSCI
Clcnati3 vcr.^icoior Siruill
H. Michticl Dennis December ,76
.
->«&-
--LbLAnr^JH^ ^T^^n ^"^W"iha
PLANTS OF TKXAS
jiEiBAiirx ioi^ii»y xminfitvr cjciiEkfnrr
*jr
CXon^itls rotictii rjilt.
*.t.i,
HOLOTYPFOF:
i-
roadside.
Clematis curniocnshT}. Estcs nc.ir
U^ \^
VAi9
S)UT1 nf: J, F* }if^:mr>n \f^%
\
FiG-2.Holotype (J.RHennen408, SMU) oi Clematis carrizoensis.
NEW FROM
ESTES, A SPECIES OF CLEMATIS TEXAS 69
Fig J. f/en7jf/5 ramzoe/js/i. A. Portion of plant showing glaucous abaxial leaf surfaces. B. Close-up of abaxial surface of
leaflet showing raised-reticulate venation. C. Flower, front view (note crispate sepal margins). D. Fruit. Photos above
are from plants collected at same site as D. Estes 07032.
dm
ternate, largest at about mid-stem, spreading, to 2.0 long, longer than wide
to as wide as long; petiole stout, equaling or more rrec[uently shorter than the
cm
lowest leaflets, to 6.0 long, glabrous and glaucous, base of opposing petioles
usually connate; rachis geniculate; leaflets symmetrical or asymmetrical,
8-10 on imparipinnate 25 on proximal-most pinnate-ternate
paired, leaves, to
leaves, spreading to erect, reduced distally on rachis, the distal-most often form-
70 BRIT.ORG/SIDA
22(1)
ing a short simple tendril, proxiinal-most entire or 2-3-lobed to trifoliate, ovate,
cm cm
broadly ovate, or subrotund, leaflets to 7.0 long and to 6.0 wide, coria-
ceous, base shallovvly to deeply cordate, rounded, or truncate, margins slightly
and
revolute, leaflet apices lobe apices rounded, retuse, or occasionafly acute,
mucronate, adaxial and abaxial surfaces strongly reticulate with vein or-
all
ders conspicuously raised, lorming an intricate reticulum, hght green adaxially
paler abaxially drying pale olive-brown olive-green, gfabrous and gfaucous
to
on both surfaces but more conspicuous on abaxial surface; petiolules 1.5-3.0(-7
cm)
long, one-fourth to one-third length of leaflet or rarefy one-half to as long
and
as leaflet, stout, glabrous glaucous. Flowers solitary on long axillary pe-
duncles or rarely axillary and terminal, nodding, ovoid peduncles
or urceolate;
cm
erect, curved or frequently abruptly recurved at apex, 7.5-17.0 long, stout,
glabrous and glaucous, with 2 foliosc bracts; bracts sessile or subsessile with
mm,
petioles to 4.0 positioned mostly near the middle of the peduncle, base
subcordate to deeply cordate, margins entire or 2-3-lobed, otherwise similar in
and
shape, size, texture, vestiture to leaflets, Sepals erect, connivent, ovate-lan-
cm cm
ceolate to oblong-ovate, apices reflexed, L8-3.0 long, 0.7-1.3 wide, coria-
ceous, ca. 12 nerved, abaxially yellowish-cream, or greenish-yellow and often
faintly tinged with lilac proximally adaxial surface similar in color to the
abaxial surface at least distally mostly drying tan or light brown, edges nar-
rowly and
crispate, wdiite-tomentulose, abaxial adaxial surfaces glabrous. Sta-
cm
mens
linear, 1.8-2.4 long, the filaments flattened, in dried material dark
brownish-red in the proximal half densely pilose from below middle apex,
to
,
mm
mm
anthers 6.0 long, connective extended 1.75-2.0 beyond anthers, pilose.
cm
Fruit tightly clustered in spherical heads 4.5-8 diameter, brown,
in light
mm
body nim
rhomboiclal-ovate, 6.0-9.0 long and 6.0-7.0 wide, acuminate
at
both ends, connpressed, marginally thickened,
sericeous; style curvate, 3.0-5.5
cm
coma
with yellowish-brown plumose coma,
long, a hairs of spreading
to
mm
Chromosome number unknown.
ascending, to 3.0 long.
W
Additional specimens examined: TEXAS: Cherokee Co.: ca. 9.5 mi F of Troup, ca, 6 mi of Price, ca,
Hwy
N
3,5 mi of 13, sandylands. 12Jul 1977, C. Ajilvsgl %138{\]R]T). Smith Co.: sandy woods cast of
May
Swan, iO 1902,/. Rcverchon 2962 [two sheets] (MO); on R.R. [railroad] near Lindale, Apr
1923, J.
Rcvcyxhon s\f!. (MO); western Tyler along Cotton Belt Railway, east end of Pine Burr Rc[., infreciuent at
woods May
edge of along railway, 21 1^)49, V.L. Cory 56212 [SMU); western Tyler, S of Pine Burr Rd,
Aug
infreqnent in sandy woods. 10 1950, VL. C^iiy 57^>60(SMlJJ;just N of Interstate 20 in woods E
oi'
&
Old Tyler-Mineola Rd., 20 Oct 1965, D.5. Corrdl KB. CorrcU 32041 (LIJ; sand)^ field uith scattered
SW
post oak in angle ubere US Rte. 69 and Loop 323 intersect, north edge of Tyler, 28 Aug 1966, DS.
Corrcll 33513 (LL); pure sand in field on Loop 323 near intersection with Rte. 69, Tyler, 6Jun 1969, DS.
SW
Coi rdi 37401 (LL); in angle oi uitcrscction of US 69 and Loop 323, N edge of Tyler, under oaks
next to 12 Oaks Motor Hotel, growing in sandy field undcv QucvcusiuLafia.Q.margayclia.w'nh Opun-
WM.
NAV km WSW'
tia^ Yucca, 22 Jun 1975, Dciiiiis 5/7/8 (T[:NN); portuMi of city of Tyler, 0.75 of
TX Hw^ Hwy m SW Hwy
junction ol State 323 Loop and US 69, ca. 20 of junction of 323 Loop and
N
Silver Creek Dr., 32'-22'42.1"N, 95'-'20'20.6AV, ak^ig edge of scrul4^y oak luckory woods and in a
small opening nearby rooted in deep sand and scrambling over small shrubs and hcrbswvnh Qucrcus
9
NEW
ESTES, A SPECIES OF CLEMATIS FROM TEXAS 71
Fig. 4. Flowers of Clematis texensts (A), Clematis carrizoensis (B), and Clematis versicolor (C).
spp., Carya. Rh usaw7nai lea, Prunus gracilis, and Toxicodendron puhesccns, May 2005, D. Estcs 07032
(GH, NY, TnNN, VDB)_ Van Zandi Co.: 2.3 mi E oi Ben Wheclci; sandy loam, 6 May 1951, R. Van Vleet
(sum
1257
Ha
endemic endemic
DLst bu tiona?!^ tat.— Clematis c<ar?i^oensis or nearly
ri bi is
km
to the Carrizo Formation, a narrow zone (19 wide) of relatively deep depos-
km
of coarse to find sand that trends southwest to northeast for 720 from
its ca.
(Macbryde and Weakley
south-central to northeastern Texas 1933; Sorrie 2001).
and Weakly an endemic
Sorrie (2001) identified additional 12 taxa or nearly
endemic Within
to this formation. the Carrizo Sands, C. carrizoensis has only
been collected from three contiguous counties, Cherokee, Smith, and Van Zandt,
in the northeastern section of the formation. Clematis carrizoensis grows in
all
or along the edges open, well-drained, prairie-like areas in sun or partial
ol full
shade. Within these communities, carrizoensis along the ground or over
C. trails
low herbs, shrubs, or fences, apparently rarely climbing higher into low
branches of Oak-hickory woodlands or thickets border these Domi-
trees. sites.
C
nant tree species associated with one population ot carrizoensis in Tyler, Texas
of D. Estes07032 cited above) include Quercus incana Bartr, marilandica
(site Q.
Mucnch., nigra stellata Wang., Carya texana Buckl, Sassafras albidum
Q. L., Q.
(Nutt.)Nees,and Frequent small shrubs and woody
L//?nuscrassi/o[ia Nutt.
trees,
&
vines w^ere Opuntia sp., Prunus caroliniana (P. Mill.) Ait., R gracilis Engelm.
A.GrayR/iusaromatica /inum Rubus
Ait., R. copal L., R.gl<abra L., ri via /is Michx.,
t
Garden
5ti//ingia sylvatica ex Toxicodendron puhescens Mill, Vacciniuni
L., P.
arhoreum Viburnum
Marsh., rufidulum Raf., Vitis mustaiigensis Buckl.,
V.
and
rotundifoUa Michx. Yucca sp.BaptLsiasp.,Cn.idosa)/us(cxanus(Muell.-Arg.)
Mimosa dntmmonchiTorr
Small, Crotona?'gy?^anthenu(sMichx., sp.jParonj^cbia
&
Rumcx
A. Gray, Pteridium aquilinum Kuhn, hastatuJus Baldw.,
(L.)
BRIT.ORG/SIDA
72 22(1]
SchizcK-hwiumscoparium Nash and rugospermum Holzingcr
(Michx.) Tahnu}}]
were herbaceous
closclv associated taxa.
May
PhcnoJogy— Clematis carrizocnsi^ flowers from early to early August;
produced beginnuig June and November.
fruits arc in late persist until
Etymology— The was honor
specific epithet ''carrizoc nsif selected in of the
C
which
Carrizo Sands, the geologic fortnation carrizocnsis apparently
to
is
restricted.
Common Names—
Odi'vizo sands leather-! lower; sand clematis
Conseryatioii Significduce— Clematis carrizoensis a rare species. have
is
1
seen only 12 specunens from three counties in northeastern Texas; 10 of these
arc [rom just four sites in a small area of Smith County. Label data from her-
uncommon
barium specimensalsoindicate where
that this species occurs.
is
it
Most specimens examined study were 30 ago
of the for this collected o\'cr )^ears
possibly indicating that this species declining or simply ovedooked. Most of
is
the populations represented by col lections are located near or in the city of Tyler,
may
Texas. These populations be subject extirpation by future development.
to
This species should be searched for in other sandy sites, particularly those as-
sociated with the Carrizo Formation, in northeastern Texas as well as in sandy
habitats iu nearby portions of Miller County, Arkansas and Caddo Parish, Loui-
siana. This species should be considered endangered and should be afforded
protection at both the state and (ederal level.
Complex
Species of ihc Clematis glaiicophylla
Five species comprise the Cglaucophylla complex. While all species differ in
morphological and mostly
rather subtle characteristics, they arc allopatric
all
inhabit different plant communities in different physiographic provinces. The
complex
in need a detailed phylogcnetic study.
is o[
Clematis addisonii^ a narrow endemic of a four county area in the Ridge
and Valley of western Virginia (Fig. uihabits dry calcareous woods and out-
1),
crops (Krai 1983)dt characterized by mostlyerect, non-twining mostly
a habit,
is
simple, thin, and inconspicuously reticulate cauline leaves, and solitary termi-
nal flowers that have purple to reddish-purple sepals with v^diitish apices.
Clematis glaucophyUa ranges from northwestern Florida west southeast-
to
and
ern Mississippi north southeastern Tennessee reportedly
to (Fig. dis-
1); it is
Oklahoma
junct McCurtain County, (Dennis Reports
to 1976). of C.gIaucoph_y/la
from Kentucky (Jones 2005) are based on misidentified specimens (D. Estcs,
pers. obs.). Throughout most of its range in the Piedmont and Gulf Coastal Plain,
C
glaucophyUa grows in sandy neutral to slightly acidic soils along streams
C
(Dennis but some Alabama and southeastern Tennessee,
1976), at sites in
glaucophyUa grows at the edges o( dr)' rocky calcareous forests (D. Estes, pers.
compound
obs.). Clcmatisglaucophylla has a viny habit and cauline leaves that
thm
have mostly and inconspicuously The proximal
reticulate
leaflets. leaf-
NEW FROM
E5TES, A SPECIES OF CLEMATIS TEXAS 73
lets are often deeply lobed, divided, or ternate. Flowers of C. glaucophylla are
borne on axillary peduncles and have sepals that are cherry-red or reddish-
purple abaxially and light colored near the abaxial tip and on the whole sur-
face adaxially.
Clematis texensis endemic to the Edward's Plateau of Texas (Fig. where
is 1)
often associated with calcareous woodlands, edges, and stream banks.
cliffs,
it is
The species has a viny habit and compound cauline leaves with relatively thick
and conspicuously The proximal vary from simple
reticulate leaflets. leaflets
lobed or ternate. The flowers are borne on axillary peduncles the sepals
to aTicl
and
are scarlet or rose-red abaxially near the tip adaxially (Fig.
4).
Clematis versicolor has a bicentric distribution with part of range cen-
its
Highlands southwestern western
tered in the Interior ot Missouri, ArkaTisas,
Oklahoma Low
and eastern and the other portion centered in the Interior Pla-
teau of central Tennessee, extreme northern Alabama, and south-central Ken-
tucky usually associated with calcareous dry woods, and
(Fig. bluffs,
1). It is
vmy
roadsides with exposed limestone. Clematis versicolor has a habit, relatively
compound
thick and conspicuously reticulate cauline leaves with the proxi-
mal leaflets entire or rarely lobed or divided, and flowers borne on axillary
C
The
peduncles. abaxial surfaces of the sepals of versicolor are mostly pur-
and
plish-red proximally often are cream-colored or greenish distally (Fig. 4).
among
sandy oak-
Clejnatis carrizoensis restricted to prairie-like areas
is
woodlands The
hickory in three counties in northeastern Texas (Fig. species
1).
compound
has a viny habit, thick and conspicuously reticulate leaves that have
proximal leaflets frequently lobed, divided, or ternate, flowers borne on axil-
lary peduncles, and sepals that are abaxially yellowish-cream and faintly tinged
with proximally
lilac (Fig.
4).
Members
Characters Useful for Distinguishing of the Clematis glaucophylla
Complex
The members of the glaucophylla complex can be distinguished by differ-
C.
ences in habit, leaf dissection, leaf texture, leaflet shape, degree of vein reticu-
and geography
lation, flower position, sepal color, habitat, (Table Fig.
1).
1;
C
member
In terms of habit, addisonii the only erect non-viny of the
is
m
complex. has stems that are mostly less than tall whereas the other spe-
It 1
m
cies in the complex have viny stems mostly greater than in length. Dennis
1
C
complex
(1976) noted that while addisonii the only species in the that ex-
is
C
hibits this growth form, occasional individuals of addisonii bear apical
branches that often become entangled and approach a viny habit.
Leaf dissection a character that only generally useful for distinguish-
is is
complex, exception being Clematis addisonii
ing species of the the addisonii.
C.
has leaves that are mostly simple but occasionally vary to pinnate with up to
The complex have pinnate
six leaflets. rest of the species of the leaves that are
74 BRIT.ORG/SIDA 22(1)
Table ^Characteristics of the C/emaf/sg/aL/cop/iy/Za complex, compiled from data presented Dennis
in
and
(1976) Pringle (1997).
camzoensis
texensis versicolor addisonii glauGophylla
m m m
m m
Habit vinv. > viny, > viny, > erect, < viny >
1 1 1 1
I
Leaf Dissection -pinnate to 1-pinnate to 1-pinnate, simple,or 1-pinnate to
distal
1
pinnate- pinnate- proximal leaves 1-pin pinnate-
ternate, ternate, leaflets nate ternate,
proxinial proximal mostly proximal
leaf- leaf-
commonly commonly
unlobed,
lets lets leaflets
commonly
lobed lobed
occasionally
2-3
lobed lobed
or 3-foliate or 3-foliate
or 3-roliate
Leaf Texture coriaceous coriaceous coriaceous
thin thin
Venation
mticulate, reticulate, reticulate, not reticulate, not reticulate,
raised raised raised not raised not raised
Flower Position mostly axillary mostly axillary mostly axillary mostly terminal mostly
axillar
Flower Color
scarlet to yellowish- purplish-red to purple to cherry red to
rose-red cream, bluish-lavender, purplish-red, reddish-
creamy
ac-tinged or whitish distally purple
proximally greenish
dista
to pinnate-tcrnate with more than six leaflets. The degree of coinpounchng of
proximal
the leaflets a useful yet non-diagnostic character that according to
is
EricksoR (1943) "must be used with judgment." For example, Erickson (1943)
C C
may
noted that leaf dissection generally be used to separate tcxcnsis and
\'Vrsicolor.Clcmatisi^lcn{cophyUa,CAcxcnsis,^ndCxa}i'izocnsishec^^^
C
lobed, divided, or ternate proximal leaflets whereas the proximal leaflets of
versicolor arc usually unlobed or rarely lobed or ternate.
Erickson (1943) considered leaflet shape to be of general use in delimiting
taxa, especialK' the leaflet apices. Generally, addisonii, glaucophylla, and
C. C.
C. versico/or have broadly to narrowly obtuse leaflet apices. Clematis tcxensis
C
and carrizocnsishave leaflet apices that are more frequently emarginated
C
apically but that vary to obtuse, keaflets of carrizocnsis, C. tcxcnsis, and C.
vcrsicolorarc almost always mucronate
the apex.
at
Among
the species of the C.glaucophyUa complex, two groups can be de-
lineated based on leaf texture and degree of leaf vein reticulation. Clematis
C
glaucophylla and addison belong group characterized by thm
to a relatively
i i
and The
nou-reticulate leaves. other group, consisting of C. carrizoensis, C.
C
tcxensis and versicolor, has relatively thick and conspicuously reticulate
Once
leaves. again, these characters are relative and are hard to differentiate
when
only one species encountered and can sometimes be
is difficult to assess