RECOGNITION OF LECHEA PULCHELLA VAR. RAMOSISSIMA (CISTACEAE)

2007·2.1 MB·English

by  Bruce A Sorrie

RECOGNITION OF LECHEA PULCHELLA RAMOSISSIMA
VAR. (CISTACEAE)
Bruce Alan S.Weakley
A. Sorrie
University of North Carolina IHerbarium University of North Carolina Herbarium
North Carolina Botanical Garden, CB 3280 North Carolina Botanical Garden, CB 3280
Chapel North Carolina 27599-3280, USA. Chapel North Carolina 27599-3280,
U.S.A.
Hill, Hill,
ABSTRACT
&
A
new combination made: Lechea pulchella ramosissima (Hodgdon) Weakley,
Raf. var. Sorrie
is
RESUMEN
&
Se hace la nueva combinacion: Lechea pulchella Raf. var. ramosissima (Hodgdon) Sorrie Weakley.
&
Hodgdon
(1938) revised the genus Lechea and recognized three varieties within Britton Hol-
L. leggettii
hck. The nominate variety (named Hodgdon), ranges from eastern Massachusetts northeastern
var. typica to
Hodgdon
Ohio and south to northern and western Virginia. Variety moniliformis (E.R Bicknell) occurs near
New
the coast from southeastern Massachusetts to southern Jersey; localized disjunct populations occur
within old shorelines of the Great Lakes in Indiana, Michigan, Ohio, and Ontario. Variety ramosis-
Illinois,
Hodgdon
sima occurs from southeastern Virginia to central Florida and west to eastern Texas. In a revision
of Lechea in the southeastern United States, Wilbur and Daoud (1961) accepted Hodgdon's var. ramosissima,
but without assessing distinctiveness.
its
many
Wilbur (1966) argued that Rafinesque's older names should be used for of the names used by
Hodgdon and Thus, became synonym However, paper Wilbur
others. L. leggettii a of L. pulchella Raf. in this
am
declined to recognize varieties, stating that not convinced that these tendencies represent biological
"...I
New
and
varieties or subspecies." In a study oi Lechea in Jersey, Barringer (2004) did not recognize varieties
did not mention the southern taxon ramosissima.
AND METHODS
MATERIALS
We
NCU,
examined over 150 specimens from VPI, and WILLI. Specimens represented broad geographic
a
we
range from Massachusetts Florida and Louisiana; however, paid special attention the potential zone
to to
of overlap of var. pulchella and var. ramosissima in the mid-Atlantic states. Specimens represented 13 coun-
We
in Virginia, 28 in North Carolina, and 3 in Maryland. assessed Hodgdon's (1938) key characters
ties
We
number, and
of seed seed shape, density of capsules, panicle shape, panicle branching. also assessed
plant height.
RESULTS
We
found that these characters, used in combination, satisfactorily separated a high percentage of speci-
if
mens with mature The most useful characters were seed number, seed shape, density of capsules, and
fruit.
plant height. Table summarizes these characters. Density of capsules refers to the arrangement of capsules
1
on the ultimate branches: in var. pulchella they vary from a tight cluster (or glomerule) to a crowded row
of capsules that actually or nearly touch one another; in var. ramosissima the capsules vary from a loosely
mm)
may
arranged row (capsules separated by one to a few to a row of capsules that touch one another.
Hodgdon we
Panicle shape and branching, defined by were apply but
as (1938), difficult to effectively, in-
them
clude here completeness.
for
We
experienced little difficulty in assigning specimens to var. pulchella or to var. ramosissima. All speci-
mens
from North Carolina and southward exhibited characters of var. ramosissima. with no characters of var.
-
Texas 369 371 2007
J. Bot. Res. Inst. 1 (1):
.
. ,
370 Journal of the Botanical Research Institute of Texas
1(1))
Table Morphological characters used to distinguish varieties Lecheapulchella.
in
1
.
• •
Mat. pulchella var. ramosissima
number
seed
3 (-4) 2(-3)
seed shape relatively narrow and 3-sided, broad and compressed, or obscurely
sections of an orange 3-sided
like
density of capsules clustered branch or sparse row, sometimes
at tip, in a in a in a
dense row dense row
cm cm
25-55 35-80
plant height
panicle shape and branching ovoid to subcylindric; principle subcylindric to subglobose; principle
branches subequal, short branches diminishing upward, long
relatively relatively
pulchella. Similarly, specimens from Maryland and northward exhibited characters only of var. pulchella (or of
var. moniliformis). Virginia specimens from Caroline County (Wieboldt 9538 VPI) and City of Suffolk, (Fleming
11235 WILLI) had three seeds per capsule and seeds variously shaped, but had capsule density and plant
height characters typical of var. ramosissima. Virginia specimens from Fairfax County (Hunnewell 6506 VPI)
and Prince William County (Jownsend 3532 VPI) had three seeds per capsule and seeds variously shaped,
but had capsule density and plant height typical of var. pulchella. These specimens apparently are examples
—
Examination specimens zone and
of hybridization. of additional in the of overlap in eastern Virginia in
—
may
adjacent Maryland and North Carolina reveal additional evidence of natural hybridization. However,
we
since a small percentage of collections appear to exhibit intermediate characters, believe that recognition
on
of var. ramosissima warranted, based the concept of varieties as incompletely separated evolutionary
is
we
entities with correlated morphological and ecogeographic differences. In this regard, stress the impor-
when
some
tance of using several key characters identifying varieties within Lechea pulchella, since there
is
any
overlap in given character.
many
While species in the eastern United States exhibit variation from north to south (Liriodendron
little
tulipijera L.), others exhibit a clinal pattern (Limonium carolinianum (Walter) Britton), Still other species exhibit
a more-or-less distinct shift of characters in the region of the Virginia-North Carolina boundary. Kalmia
K
angustijolia L. and Carolina Small, considered species by some and varieties by others, is an example.
&
Lechea pulchella Raf. var. ramosissima (Hodgdon) Sorrie Weakley, comb. nov. Basion™: Lechea RaL
pulchella
&
NewFl.N. Amer. 1:91. 1836. Lechea kggettii Britton Rollick var. ramos[ssimaHodgdon,Rhodora 40:1 19-123, pi. 491, fig. 3. 1938.
Type: U.S.A. Mississippi. Jackson Co.: Ocean Springs, 29 Jul 1896, Pollard 1109 (holot\te: GH; isotypes: NY, US).
F,
Lechea pulchella ramosissima ranges on the coastal plain from southeastern Virginia (Accomack, Caroline,
vdiT.
NCU,
City of Suffolk, City of Virginia Beach, Greensville, and Northampton counties; specimens VPI,
at
WILLI) south central Florida (reaching Hernando and Martin counties, Atlas of Florida Vascular Plants,
to
NCU)
www.plantatlas.usf.edu) and west western Louisiana (Beauregard Parish, specimen and eastern
to at
&
Daoud
Texas (Orange County, Turner Tennessee County, Wilbur
2003); disjunct in central (Coffee
et
al.
1961) and northeast Georgia (Rabun County, specimen NCU). Habitats include dry mesic pine-oak
at to
woods, pine savannas, pine flatwoods, borders of shrub-tree pocosins, moist powerlines, dry roadsides,
fields,
many
and
railroad rights-of-way. In of these habitats, a recurring disturbance.
fire is
REFERENCES
New
pinweeds Bot Soc 13L261-276.
Barringer, 2004. Jersey {Lechea, Cistaceae). J.Torrey
K.
A
Hodgdon, 938. taxonomic study of Lechea. Rhodora 40:29-69, 87-1
A.R. 31
1
Sorrie and Weakley, Notes on Lechea maritima var. virginica 371
and Volume
Turner, H. Nichols, G. Denny, 0. Doron. 2003. Atlas of the vascular plants of Texas. Botanica
B.L., 1.
Research Institute of Texas Press, Fort Worth.
Wilbur, 1966. Notes on Rafinesque's species of Lechea (Cistaceae). Rhodora 68:192-208.
R.L.
Wilbur, R.L. and H.S. Daoud. 1961. The genus Lechea (Cistaceae) in the southeastern Unites States. Rhodora
63:103-118.