A NEW SPECIES OF BRAZORIA (LAMIACEAE) FROM THE CENTRAL MINERAL REGION OF TEXAS

7 Pages·2003·4 MB·English

by  Matt W Turner

NEW
A
OF BRAZORIA
(LAMIACEAE)
SPECIES
FROM
THE CENTRAL MINERAL REGION OF TEXAS
Combs
School of Business
AustinJX78712,U.S.A.
ABSTRACT
&
ilar to truncata (Benth.) Engelm. A. Gray
B.
f
lobes of the calyx. habitat and edaphic
le Its
photographs, dot-maps, and keys
;criptions,
RESUMEN
-10 y Burnet). Se asemeja a truncata (Benth.;
B.
my
As
noted previously in overview of the genus (Turner 1996), the only three
known me
collections of Brazoria that were from the central mineral region
to
of Texas prior to 1996 (from collections housed at BRIT GH, K, LL, OKL, TAES,
TEX)
possibly constituted an undescribed taxon, but lack of extant popula-
tions precluded their recognition. Subsequently, sightings of populations of the
taxon by Marshall Enquist in this region prompted three years of additional
me
fieldwork by myself. These studies have convinced that the plant
is
undescribed and deserving
of specific recognition.
is
M.W.
enquistii Turner,
sp.
mi ESE
Masc
ca. 11 airline of
:
GH, MO, TAES,
types: BRIT,
1
cm
Erect annual herbs mostly 15-40 high, simple, or branched at base; latter,
if
branches immediately ascending from Stems pubescent below
base. square,
Leaves opposite Iowli Icucs ptisistcnt usuilh
_s
il
9cm cm
Ivspatulate) 5 long 2 wide often tapciing
1
margms
undulate to denticulate upper leaves oblong
and Matuie
usuall) paitly clasping spikes
sessile
mm
Tcd with lower mternodes mostly 2 5 4 long
mm
u
mostly 8-12
base pedicels ovate orbicular
ol
s
mm m
2-3 cam
mostly length Calyces broadly
h hail
s
ul ^ Si 10)1111 nlongbilabnteth lower lobe^ mostl) truncate VMth
itc
tooth uooll) -mentose ub^sc ithi niHN eghnc luhrh^irsreaclimg2
tc vx
hdlowK mucK
length uppei middle lobe usui IK une ue ^nate
in oi
ti
m
lateral lobes ueionitetoipieul Ue ipinte ,hi uluhi huisseai tered
ei e
mduppei
bihbntepilelaven
bothlo^Ae, lobes Corollas 15
Kpu
indusuilU distinetl) \emed spaise bciulent ong the uppei su [ace
\\
I
hp bifid n\et hptiifid lobes usu all)( margmatc thioats\Mthan nulub
11
1
mm
loaMsof 2-3
pen above ovaiy maculate
pet dieul u coiolla ith
ill\ \\
hump
mte
met on lov surface bcneitlistai nens Stamens 4 fertile the
ei
calmmwi
pmlongei dcatbascoKie
than the posterior Filam ents -poi
conspicuo dnged, arched h ward near upper
usly^^ villous, apices; pa:irfree
1
,
mm; mm,
from adnation 3-4 innermost
to corolla for lower, pair free for 1.0-1.5
with mutually opposing "bulges" or "shoulders" that, together with overlapping
hairs, hold style in epipetalous position. Thecae apiculate laterally at base, dark
purple and ringed with white; upper pair slightly smaller than lower
(ca. 1.2
mm
vs 2.0 mm); ventral (rarely dorsal) surface of connective tissue between
mm
lobed, glabrous; branches linear-lanceolate. Nutlets mostly 1.5-2.5(-3.5)
long, strongly trigonal, with incurved hispidulous hairs, rarely glabrous.
Distrihution—Tht most geographically isolated species of the genus,
known
Brazoria enquistii only from three counties— Burnet, Llano, and Ma-
is
son (Fig. 1)—and have only been able to locate extant populations in the latter
1
Many
two of these. attempts to ascertain distribution extensions (beyond what
made
reported here) have been in the surrounding vicinity over the past
five
IS
km
years to no avail. Although only ca. 130 separates the taxon (Llano/Burnet
from
Co. border area) the nearest populations of truncata (Bastrop Co.)
B. (Fig.
the intervening distance presents the sand-loving genus with a barrier of
2),
limestone, the central mineral region being renowned as a granitic outcrop
(.which weathers sand) surrounded by calcareous This geographic
to soils. iso-
which
unlike the eastern species of the genus
i-/c(hifdt.—/^/t;C("'ic; CMC/
!( i.sf i,
i
tend to prefer the loose white sands of xeric slopes, grows almost exclusively
along granitic streambeds of the Llano River watershed. Only four of the 16
populations discovered by the author (sites of Turner 72, 95 and 96 are not
71,
)
Documented
distribution
Fig. 1 o1
.
m
More
along such streambeds (but even two of these are within 100 of one).
specifically, the species rarely found near the water's edge, but rather occurs
is
m
embankments 10-20
on the sparsely-vegetated sand within of adja-
raised,
embankments permanent wa-
The seems along
cent streams. species prefer
to
One
and only rarely found in dry washes and gullies. of the largest popu-
ter, is
was
lations (estimated at 10,000+ individuals at the type locality) discovered
on sand middle Willow Creek approaches the
a large, flat, island in the of as it
widen
Llano River Indeed, the species seems to flourish in creek beds as they
downstream near mouths (presumably because the waterways accumu-
their
become
late more sand), and becomes less abundant upstream as the creeks
known and
narrower Only three of the 22 sites to date (both historical extant)
south the Llano River
of
lie
AW known month May
Phenology— from
collections are the of
enqu
nble:
.Ther long
lishing character of the taxoi
ts
and and key foUowmg), which aln
well-developed bracts (see Fi
com whose
the developing buds, in stark to the shorter bracts of truncata
St B.
compact rows have
buds, exposed to view, dispk themselves in the that
left
ame Another
of "rattlesnake flower" obvi-
which genus (2-4
rnode length the smallest of the
is
(closed triangles); B.ff
(7
mm
m m
m
5-6 truncata 8-13 pulcherrima
vs. for B. var. truncata, for B.t.v ^L
Amdell) M.W. and 8-20(-30) nd
Turner, aremaric Lundell) provides
for B. a for
compact
extremely
spike.
1
Less obvious characters distinguishing the taxo n from uncata mclude
B.
t
mm
mm),
longer bract ciliation (2-3 vs. 1-2 a distir ct shape to the lower lobes
the calyx (truncate or with only 1 "tooth" vs. wit h 3-5 "teetf "), and a subtle
shape upper middle
Terence nr the of the lobe of the calyx uncatetoshal-
(t
1
known, was made
So far as the first recorded collection of the taxon in 1910
Some
Kingsland (Llano Co.), Hastings s.n. (LL). 20 years later, the second re-
)rded collection from an area six miles northwest of Valley Spring in Llano
is
Some
Bauman's 6286 (TAES). 30 years elapsed before the third collec-
[sic]
3.,
was made
3n (in 1962 in Inks Lake State Park, Burnet along Clear Creek,
Co.,

&
Corrdl Ogden 25300 An
(LL)), extant population has been found
at a loca-
approximating
tion the second
collection (Turner however,
69); the author's re-
peated attempts
at locating living populations in the Kingsland area and
in
western Burnet Co. have been The may
unsuccessful. Kingsland
area have
be-
come
overdeveloped and/or damming
the of the Colorado River Lake
for LBJ
with Dam) may
(in 1951 the Alvin Wirtz
have influenced
the Repeated
habitat.
visits to Inks Lake State Park, with
special attention Clear Creek and
to Spring
A
Creek, have
likewise revealed nothing. 1996
sighting by Marshall Enquist from
the Llano/Burnet Co. line area (near Buchanan Dam), prompted
this investiga-
but roadwork,immediately
tion, kical
thereafter, completely and
altered the
site
no furt her sightings have been made
in the area At
to date. the present, the west-
ern edge Burnet
o^ Co. represents the eastern limit the
for species.
Brcizorui most
cnquistii the geographically
is restricted taxon of the ge-
nus, distributed primarily within two
just counties. Like truncata
B. var.
pukhcrnmci which
is restricted to about five counties in northeastern Texas
Turner
1996), B. enquistii can be locally abundant, which would hkely
I pre-
lude
from endangered On
It species status. the other hand, more
infre-
is
it
quent in occurrence, tending appear
to in isolated patches (due
to special-
its
ized habitat), rather than being
loosely scattered along the roadside. The number
M
individuals at a given location can vary sharply from
year to year: the type
mentioned
locality above contained over 10,000
plants in 1996, but only about
number
1%
of that
in 1999.
-The
Choice rank
taxon
of here treated rank
is at specific the following
for
-easons: exhibits several distinguishing morphological
it characters (outlined
has and
ibovc); a habitat edaphic preference from
it distinct the other taxa of
he gen embankments
(raised of streambeds
lis in purely granitic sand
xeric
vs.
>lopcs ol loose, white, non-granitic sands open woodlands and
in
stabilized
hmcs); geographically and
edaphically by
it is isolated the surrounding
cal-
which
u-cous
soil erects a barrier to gene exchange- and no populations
inter
ULdiate
to lelated taxa have been
its discovered
-The
hlymology named
species is for Marshall Enquist an attorney
in the
Utcgion withoutuhich
paper would
this not have been MrEnqmsts
possible
1
xcd
k guRk
ni loi isi u Cfnquist 1987) as well as his active reseaich on
native
I
cMsMot
ilnxludint, Xutmonc Desmodium
Crataegus and
Pfunus) have been
W
&
Mason 5 mi
TX along Wrights Creek, 16 May 19 99, Tu-rner Rohhi ns97 (TEX). Co.: ca.O.
of jet 29,
CR
V
of Castell on TX 152 in creek bed, 14 May 19'56, Tui^ner 63 (TEX );ca. 11 airiine mi \ of Llano , off
ESEofMa
May
404 San Fernando Creek crossing, 19
at
Art Hedwigs Hill Rd, 3 mi N of US Hwy 87 &1.6 mi S of TX Z9ak)ng Willow Creek, 18 M;ay 1997,
;
68^X1 TX Hickory GnoveR along San Fernando CTeek, 18
Turner 2.7 mi S of Pontotoc (jet 71) on d,
I
May Jurner
;TX71)onH Grove Rd, 1997
May 1997, Turner 70 (TEX); 2.2 mi S of Pontoltoe (jct ickor y If5
W
TX llmiSonFlyCapRd.i
Gap mi on then :hen 0.2
(TEX); HUlis Fly Ranch, 2.5 of Pontot;oc 71,
71
FlyGapRdai
May
mi Wtoentrance, 12 2002, Hi;iis286(T
N
mi ENEo Mason on iickory Grove Rd,: mi of jct with
May 2002, Hillis 293 (TEX); ca. 14 airline f 1 ^.5
N rX29at
Union Rd, 18 May 1997, Turner 72 (TEX); ca. 12 mi due E of Mas,onor1 Union Rd,0.6 mi of 1
ENE
May Tarner79 (TEX); ne mi of Mason, o n Eaton
crossing of Martin Creek, 10 1998, ca. 1 1 airii
mi
Cemetery Rd, mi E of FM 1900 at crossing of Ma rtin Creek, K3 Ma)7 1998, Turner 80 (TEX); ca. 8
1
m ow May
N nchofEWill
N N TX Creek) 16
ENE Mason, on Art Rd, 2.4 mi of jct 29,75 of creel<(bra
,
Tu rner & Rohhi ns 95 (TEX); ca. 8 mi ENE Mas.on.onNArt Rd,2 .8 mi N of jct 1:X 29, 16 May 1999,
1999,
A REVISED KEY TO THE SPECIES OF BRAZORIA
mm
bracts with hairs 0.1-0.2 in length; mature plants often be
Floral ciliolate,
southern Texas
ceolate to spatulate;
often not basally
s
long;lowerlot
Mason
gion (Burnet, Llano, Co.)
Floral bracts at base of pedicels
.
ACKNOWLEDGMENTS
the
and Curators the following institutions for
the Directors of
ain grateful to
I
GH, OKL, TAES,
450 herbarium specimens; BRIT, K, LL,
approximately
loan of
with the Latin diag-
TEX. would also like to thank Gayle Turner for assistance
I
my
additional locations of
David bringing to attention B.
nosis, Hillis for
Tom Wendt and Lindsay Woodruff the use of
and for
near ranch,
enquistii his
and kindness
(TEX-LL) and the steadfast care
Resources Center for
the Plant
m
my many
me
answering questions.
have extended
that they to
REFERENCES
and Warnockia
genus (Lamiaceae),
M.W. 1996. Systematic study of the Brazoria
Turner,
new genus from Texas. Syst. Evol. 203:65-82.
(LarTiiaceae), a PI.