THE VASCULAR FLORA OF MADISON COUNTY, TEXAS

39 Pages·2001·24 MB·English

by  Amanda K Neill

THE VASCULAR FLORA OF MADISON COUNTY, TEXAS
Amanda Hugh
and D.Wilson
1
Neil!
K.
=
USA.
'Station.^?7843-3258,
College
ABSTRACT
Cyperaceae
spp).
(
)' spp.). Tin ]\ u> arc ..m eel list that includes
i i
n name, collection citations, anc Twlicihei thai specie
i
W
duded,n,he
h
S e
P
; tottrrru
rspedetlnd
n en
ra re a d S
(
RI'SrMFN
!m
on [inn <o.
noii
ii 1 i \ i. i u 1 ' i i I l i i i i ii i
m
up l,o, [>,.„, u-< SA p n„ u linuompil kirn n un. h-t u -nieiit ulaqiu Inv.
1 i I i i ,
m
nil.
v< ml in u nl d. la ih ioik in' u
( i« I i ( i \ ii t ii i 1
INTRODUCTION
many
Madison Count) like oihei o until ol ha n ed an in-depth flo-
1< i
1
I
lom>k
Texasbota-
evaluation \u>ni| u im ha n u,oalof
ristic U id<
it - ,t
r f 1 t
M) was intended irn-volume but
nists.Lundell's Flora \n-a h> to be a series,
oj
/,
Ma
the project was abandoned in 1955. Correll and Johnston's nualofthe Vascu-
and remains only
Plants Texas (1970) incorporated Lundell's work, the
lar
of
reference with dichotomous keys encompassing the entire state. Updated check-
Gould Hatch
of the Texas flora have been compiled by (1975a), et al. (1990),
lists
and Jones Although these reference species by region or vegeta-
et al. (1997).
due
no county-by-county species information available to the
tional area, is
Manual
Reed compiled the the Dicot
dearth of local floristic studies. (1997) of
Madison
Flora Brazos and Surrounding Counties, technically including
of
County. However, than 200 collections from this county were available for
less
A&M
(FTC
reference from Texas University's two herbaria at the time Her-
Bnn
barium ipeeimen inten reference).
M
ei
Almost a century ago, Texas botanist William Bray stated that "before the
kxas
loia suffers further radical changes, the schools of the ought
ol state to
I
coopciaic ni securing a complete and authentic species represented by
oi
lisi
carefully collected and well-preserved specimens" While
t,Brav E)0b). the col-
haw
and
leges universities of Texas a great n adit ion ecological and system-
oi
,u ic siudies a century has brought us but little closer to a modern state-wide
loia. radical changes which Brav spoke continue unabated and
lie lorist ic o\
i I i
often unobserved, and the labor intensive loras of Texas counties are woe-
still
I
lully tew.
The
were and
objectives of this count)' flora identify preserve
to collect,
)
I
specimens ol all vast u la plants occurring in Madison ,ount\ lexa m
r ( ' g<
' i
ate a species lor he count v and delineate pal terns plant communities by
list oi
I
and
habitat preference; 3) analyze the flora for disjuncts, notable range exten-
endemics, and sum-
sions, recent invaders, rare taxa. This article provided as a
is
mary
of the first authors M.S. thesis research (.Neill 2000)* information also
is
available on the Madison County Flora Website <http://
at
B10COURSE.B10.TAMU.EDU/graduatc-students/neilla/madhome.htmxThis
site includes annotated species searchable in several formats, as well as
lists,
mans
and
links images.
to
Description
Site
Madison County comprises
302,451 acres (122/398 ha) in east-central Texas
W
between 30'49' and "06' N and 9537' and 96 (Ramos
latitude 3' longitude
"1
3
1
The
1997). county bordered on the west by the [\a\asota River and Brazos
is
County, on the east by the Trinity River and louston County, on the north by
I
County
Leon and on the south by Bedias Creek and Ci nnesand Walker coun-
The county and
ties (Fig. seat largest city Madisonville, situated about 90
1). is
NNF
km)
mi
(142 Houston.
of
The
land
surlaci flat to gent rolling unl genetal .lopes to the south-
l\
l\
i
east, with elevations ranging from 420 ft (128 m) above sea level south of
Normangee
to 140 (A in above sea lead along the lower Trinity River and
3
i t »
Bedias Creek (a tributary of the Trinity) CU.S.G.S. I9b2-I989). The eastern two-
thirds of the county are drained by these watercourses, which converge the
at
While
southeastern tamed
corner. the Trinity hydrologically with
a river a
is
now
historical flood plain 10 miles wade and largely under cultivation, Bedias
Creek most deep
for length a small, creek with extensive bottomlands
is of its
oxbow
ol lakes, swamps, and frequently flooded ridge and -swale topography.
u
The
Navasota drams
River tributary ol the Brazos River the western third of
J
Madison Count}', where meanders through wide and wiyxled loodplam
a
it ol
I
sloughs, natural and
lakes, terraces, ravines.
d
The
geology of Fast Texas the result alluvium washed southward by
is
m
and
rivers deposited layers upon he advance and retreat of coastal waters
in
t
the Gulf of Mexico. This deposition occurred in the region during the Eocene
Madison County, Texas
and
and map bottomland and vegetation zones. Adapted from Gould et (1960) Neitsch
Location of soils al. (1
Fig. 1
.
Epoch (58 to 37 mya) of the Tertiary Period C pearinj L991) The Eocene layers
members Group and com-
deposited Madison County are of the Claiborne are
in
and (Neitsch Neitsch
posed sandstones, lignites 1994).
of clays, shales, siltstones,
and
with upland three
(1994) 12 associations in the county, six soils
lists soil
loamy sands and Three bottomland soils of alluvial clay
prairie soils, all clays.
modern un young
cover flood pi tncl terra;
i :
The Madison County growing season averages 250 days, with a
frost-free
maximum 96T mean minimum
mean temperature and Janu-
July of (35°C) a
and and
ary temperature of ~]tVF TC). Precipitation peak:, in the spring fall av-
{
cm) (Ramos
annually
erages 41.6 in (106 1997).
Cultural History
Madison
Although no major archaeological sites have been found in County,
some Indian camp and kitchen-middens have been found that date from
sites
Caddo
3000 (Madison County Historical Commission 1984). Tribes of the
B.C.
Confederacy formed permanent settlements in the eastern part of the county,
where the people ultivated corn and squash lorn n ibes that occupied
sdic
c I
who
Creek and confluence
the county include the Bedias, frequented Bedias its
with the Trinity River, and apparently had a village in this peninsular area
Almanac
(Neitsch 1994; Texas 1951).
French and Spanish explorers, missionaries, and soldiers began leading
The Spanish
expeditions through the area in the mid-sixteenth century. first
Bucareli-where hghway
settlement, present-day Texas
21 crosses the Trinity
I
River-was
established in 1774 as an outpost against French invasion. Bucareli
was abandoned in 1779 due 10 Idocxlint; epidemics, and raids by the nomadic
Comanches
(Madison County Commission
listoneal 1984).
1
Madison County most
is historically significant for containing the inter-
two
section of earl}' roads. Originally Indian these roads were used by
trails,
missionaries, explorers, and eventual!)' The Old San Antonio Road
settlers.
known
(OSR), also as Hi Cainino Real, or the Kings Highway, connected
settle-
ments
in the hast with those in San Antonio and Mexico Today, this modern
highway forms most northern Madison town
o\ the bordei oi ounty. At the of
I
Midway, another road known La Balna from OSR and
as Trail split led south-
west to the mission at Goliad (U.S. Dept. o{ the Interior 1998).
Madison County was
organized and
in 1853, settlement increased rapidly
to a population of 3000 by 1800 (Texas Almanac 1951). By 1900, the population
had grown and
to 10,432, 71,000 acres were being farmed (.Richardson 1940).
Over 20,000 acres of this was cotton. Three railroads were through
in built the
and
county, the population peaked in 1930 at 12,227 inhabitants (Ramos 1997;
Richardson and
1940). Pasture haylancl for beef cat prod action have replaced
le
t
most
cultivated crops today. Seventy percent of the county used as rangeland,
is
and
hayland, pasture (Neitsch 1994). Fishing and hunting are important land
many
in ihccounty with
in propertic leased easonal duck and deer hunting.
to
i
Botanical History
map
Every vegetation available represents Madison an
'.omit v as ecotone. Past
i
and
ecologists botanists in Texas recognized that he area around the 96 th me-
I
which
ridian, divides the county in half, a zone where western xerophytic
is
grasslands mingle with mesophytic
eastern
forests (Bra)' 1906; Blair 1950;
Tharp
Cronquist 1982; 1920). Allied and Mitchell (1955), Correll and Johnston
Cory and Parks and Gould upon
(1970), (1937), et (1960) generally agree the
al.
boundaries of the three major vegetation zones converging Madison County;
in
commonly
these vegetation zones are called the Pineywoods, Blackland
Prai-
and Oak Savannah
Post
ries, (Fig.
1).
m
Correll anil Johnston 1970) described the vcgctational area-, largely
ac-
(
cordance with The Pineywoods
past descriptions. region of Hast Texas repre-
sents the most mesophytic area of Texas and characterized by extensive pine
is
and pine-hardwood swamps
Crests wit intermittent Madison ountvsoast
li
(
M
ern edge one the most westward-extending, tongues
is ol this vast vegeta-
nonal Blackland
\<i\c lie Prairies region lies in hive diagonal bands trending
"I
t
NE-SW
Of wo
across east-central Texas. the southern bands Blackland
of Prai-
t
San Antonio
the Prairie occupies the border northwestern Madison
rie, of
County, and the Payette Prairie is sometimes shown to extend into the south-
central portion the county. The Post Oak Savannah region mterdigitates with
ol"
the Blackland Prairies. A belt of Post Oak Savannah occupies most central
of
Madison
County.
Although no \hn iu tnuonal ndu U mi onducted Madi m
\egi in
lia\
l *
County, past lescan h h included Holistic ispeel found within the eount\
Launchbaugh
Both 952) and High tower 987) changes
J invc ligated in veg-
(J
I
etation structure n ;pon etodisturbaua Anion Diamond
in in th< u 10 Prairie.
.,
remnant communities which
(1980) described plant of the Fayette
Prairie,
is
tht south* rn disjunct of the Black land proper. ing the northern limits
Pi pla<
Grimes and Walker McCaleb
of the Fayette Prairie in counties. (1954) analyzed
m m m
the vegetation of t!u outhernP tOal ih hid( d Madison County
\
i
I
within his Oak-Hickory Forest Region. Allen (F)7! vcgetational study of the
s
)
lower Navasota described plant ommunitie dong he watershed Grimes
in
i
. i
County and pointssouth. Apparent v none the above investigators conducted
o\'
1
research within Madison County. There no voucher specimens
are resultant
for
(TAMU)
the county in the Tracy (TAES) or Biology Department herbaria Texas
at
A&M
(FTC Herbarium Specimen
University Browser, internet reference).
Mi-inons
Vascular plants were collected frequent and regular intervals in Madison
at
May
County, from 1996 to April 2000. Public lands (roadsides, railroad rights-
unm
of-way, city parks ami Miiemru n io ml habitats identified as
\\
i >
unusual were With news-
revisited over several seasons. the assistance of a local
paper article (Levey 1998), private landowners were contacted for permission
to collect on their prop* tn s >thei pi ivate land wen hosen with the aid of
(
i ; <
photographs and and
aerial .,vm lh gin in a .in bartered plain topographic
ill
soils maps, in order to u.r\ bot h gi ultural h\< toed n id-use areas and to
y
i I
unusual undisturbed Urban
investigate possible or habitats. areas (Madisonville,
Normangee, North Zulch. and Midway) provided disturbed upland sup-
sites
weedy
porting a unique, flora Riparian ind lacustrim terns were accessed
\
bridges, on private property, and by canoe.
at
At the time of plant collection, data were recorded on the specific habitat
and abundance
relative of the species in the area. Publications describing similar
research were reviewed for exposure to floristic protocol. References include
Allen McCaleb Reed Starbuck and Wilson
UQ84).
(1974), (1954), (1997), (1972).
o
R< it r< rn - us< d for pla t mil iti n u orr< 11 hn to 1°, to ii *
t I « < | i i [
et al. (1999), and Reed (1997). Grasses were identified with The Grasses of Texas
(Gould 1975b), and identifications were verified by Stephan Hatch and Dale
Kruse at the S.M. Tracy Herbarium in College Station, Texas (TAES). Sedges (Carex
sp.) were identified with an unpublished key to the Carex of Texas provided by
Stanley Jones, curator the Botanical Research Center allege Station, Texas
oi
(
(BRCH), and identifications were verified by him. Other experts consulted were
Momque
Reed (TAMU). Theodore Barkley the Botanical Research
Institute
at
Texas (BRIT), and Richard Rabelerai (he University Michigan Herbarium
of o!
(MICH).Taxonomtc onquistian system
classifit ation nti follow* d ilu
\
i ; ;i 1 1 1 ( i
U 'ronquisi 1088). wirh the exception ol familial treatment ol the Tupelo family
Chiekenspike family (Sphenocleaceae and Dodder family
iNyssaceae),
),
(Cuscutaceae). Voucher specimens collected throughout the project were de-
A&M
posited in the herbaria at Texas University in College Station, Texas
(TAMU, TAES), and are available for examination.
A search the Flora of Texas Consortium Browser C.OOOa.) revealed some
ol
m
species that the authors did not find thccounty,and these are included in the
TAMU
TAPS
Only those specimens held and were seen by the au-
checklist.
at
Numerous specimens had been landed "Madison County" but
older ac-
thors.
were northwest Normangee Icon County. The location
tually collected of in
SMU
and ASTC, TEX, SHST, and
identification of species collections held at LL,
have not been
verified.
AND
DISCUSSION
RF.SULTS
CUT
Madison County vascular plant collections resulted in a total ol speci-
mens. The flora comprised of 1041 taxa with 985 species in 488 genera and
is
m
The
136 27 Poaceat
families. fiv't largt pi ntlainili< Vstci ic (1 species),
t i
Fabaceae spp Cyperaceae and
(123 spp.), Uscn.su stricto) (70 (63 spp.),
).
44%
Fuphorbiaceae (32 spp.). These live families con tain approximately of the
species found in Madison County. Further numerical distributions of the flora
are found in Table
1.
Major Vegetational Habitats
Thirteen major habitat types were classifiable in Madison County. These habitats
are essentially those described, lor Robertson Count)', Texas, by Starbuck (1984).
Riparian habitats and lowlands include habitats in water, near water, and low
ARM), and
areas within floodplains. Aquatic emergent aquatic floating (AFF),
(
submerged (ASUJ and
aquatic are habitat categories obligate aquatic species
lor
wen dm
those plants that found in landing water io loot ling Habitats along
the banks and frequently (.two or more times a war) flooded areas of riverine
and lacustrine bodies oi water were divided into major riparian (RUM) and
(RUM)
minor riparian habitats. Major riparian habitat that of the Navasota
is
and Trinity whereas minor riparian habitats are those along creeks and
rivers,
ponds. Rowland habitats flooded once year or [uenily were divided by
less
a re.
i
woody lowland woods (TIW). lowland open
cover into terrestrial terrestrial
(TFO),and lowland mixed (TFM). Uner upland areas were similarly
terrestrial
divided upland woods upland open (TUO),
into terrestrial (.TUVV). terresii
ia.1
and terrestrial upland mixed (II VI) [wool uirbucl habitat groups, parasite
UTI
(PAR) and epiphyte better describe plant habits, but were maintained for
),
BOO
wen
consistency in this te> [wool tarbucl habitat H used. Hi bog
(,
Sphagnum
habitat applies to the acidic bogs found the deep sands of
in
Robertson County (Bryant 1977; Starbuck 1984). This habitat not present in
is
Madison Count) was
St rbucl rn trial prairie(TPR) habitat used in his text
i
specimens by Hightower remnant
solely for collected (1987) at a prairie locality.
mm
m
Although certain pi ni p kIm m uuld In linn i_i d
\
i > ! i i < > t \ i
no undisturbed county
prairie species, prairie habitats are intact in the today.
oxbow
Aquatic habitats such as lakes, stock ponds, reservoirs, drainage
Uncom
ditches, and shallow creek and river margins supported a unique flora. -
mon mCid
herbs found ju.ur lumbolutea,Thaha
tin h h bitai h
*
/>.
, >
dealbata, and Utricularia radiata. Lowland and riparian habitats contain the
most diverse flora in Madison County. The extensive wooded loodplams of the
f
Navasota River and Bedias Creek exemplify typical bottomland hardwood veg-
common
etation. Trees most in low, moist areas of the county include Carya
aquatica,Fraxinuspcnn yiviimca Nyssa sylvatua Plan ra aquatica, Querent
lyrata,Q nigra, phellos, Tilia americana, and Ulmuscrassifolia. Disturbances
Q.
and Due
to this area include logging, flooding, cattle grazing. to agricultural
use and the construction of levees and dams, the Trinity River floodplain
for-
om
umnd when
ests are less extensiu vu >Mtion ol sjk n w comparing
( < i
collections from the two major riparian habitats (RLM). Species found only
Amtoma
within the Navasota River floodplain include Aristolochia
illuttris,
tomentosa,Baptisiii alba Brunniehia ovata Carex cnmpl<iihita erut-eorvi.
(
Mikaniascandens.lHaticniaquatica^PrunusearoliiuumKTiUandsiarecurvata,
mnmm
mdma
onb
Urticachamacdiytudi lounb aiinn
<uu\
u
<<
>\>
• >
the Trinity River floodplain include Amorphafruticosa, Ampelopsis cordata, Carex
am,h
retroflexaXlcmah nln uluui qui iuu< hu viyai imi 'l'i c uto
I
noodmnhmm
Panicum
virgatum,. .m nhitn .ttnl low land open habitats
(l
r<
I |
(TLO) were typical urnd id Forested areas or river flood plains, low pas-
I
md
tures, moist roadsid Inch oth ropenarea near bodies of water. These
mowing
and and
habitats are often disturbed by grazing us support variety
th a
mm
pm
pn
wlli
weedy invade mini ml
of
n
i
i
|
upland Madison County prime and
Level sites in are locations for pastures
m
haymeadows,asthey were mostly cleared the century cropland. Most
last for
wooded with what would con upland always found
areas be idered nearly
in in
along creeks, and so \vou Id be included in die terrestrial lowland classifications
ITUM)
or this stud True wooded upland 'W'iand mixed upland habitats
siios^.'1'l
v.
I
may
do occur, and these be carcgoi ized into h ve general association types:
t
Oak - Winged Elm - Yaupon
Post Association
1.
This association encompasses nearly upland wooded sites in the county, and
all
huypical [ho 1'ostOak Savannah vegetation type he association found in
ol is
I
areas with sandy loam topsoil and, gra\ clay subsoils anil characterized by
is
Quercus Ulmusalata/and vomitoria.
Ilex
stellata,
Oak - Oak - Winged Elm
Blackjack Post Association
2.
Qucnusmanlandu.
Characterized by the presence o^ sites exhibiting this as-
u,
Oak -
sociation arc generally more poorly drained than [hose with the Post
Winged Elm Yaupon The
- association. aspect of these sites also that of the
is
Post Oak Savannah vegetation pe but was ivquent ly iound with tall grasses
in
1
such Andropogonternarius,
seen in the Blackland Prairie vegetation type, as
Soiyhastrum and Schizachyrium scopanum.
nutans,
Gum
Southern Red Oak - Sweet - Post Oak Association
3.
This association occurs the eastern third the county and character-
is in ol is
by dominance Quctx and u/mT.mdv/ These
ized a oi us jalcata styraciflua.
/
sites have acidic sandy soils Nvith \iood drainage. The best examples of this as-
unwu
Cobb
sociation arc found the uplandsalong Youngs reekc and Creek
in
(.
The
Canyon. These localities are discussed in the Unique labitats section.
I
Padina series of deep sands frequently iound these sites. Sassafras dl bid urn
is at
and Ptnuslacda are also found this association.
in
upland open habitat dFl'CYis ubiquitous and easi accessed in Madi-
lei'ivsii iul In
son ounty. ike open lowland sues, these generally roadside and pasture habi-
(
I
mm num
ma
are characterized heib and hough heic that
tats In hi is
it
many showy may Open
of the and popular wild! lowers Texas also be seen.
ol
summer when
upland habitats are first to suffer in drought conditions, even
mown
narrow county roadsides arc lor hay in [Ins county difficult to find
is
It
examples of this habitat type that have not experienced disturbance. Pasture
are frequently invaded by Prosopisglandulosa and Acacia Jarncsiana.
sites
Epiphytes found county
(EP1) in the are restricted to Pleopletis
and (PAR) found
polypodioidcs, Tillandsta rccurvata, usneotdes. Parasites in
/'.
the county include Cuscuta cuspidatd, C.glomcrata. C. oblusifolia, Orobanchc
and Phoradcndron tomentosum.
multijlora,
Unique
Habitats
m
Several localities Madison County primarily on private lands, exhibit un-
usual characteristics that deservespccial mention. Isolated populat lonsol I'mih
tacda are found at several places in the countv. but the only area that deseiwes
woods lound
designation as the Hast k as Piney vegetation typ< n out h
i
eastern Madison Count), on the peninsula formed by he eon luenceol the Trin-
I i
River and Bedias Creek and extending up Bedias Creek for several miles,
ity
hardwood
lowland Species
although area o contain ;onn forest col-
this
il
Caicx na
lected only thi habitat include \nsioloihiu ei pentai ui. hvali
in.
Dioscorea ixgodhun japonicum ninth, pracco\
xillasa in pi
'
1
Nointact,undistui'jfflpn(. oft an \ntonio Blackland Prairie are pre-
ha
;
OSR
served in Madison County. The narrow band oi prairie that once followed
way 45 has been
from the Navasota River to a few miles oi Intel tat< tgh
t
i ' 1 1
woody Although
and encroachment the road-
lost to grazing, crops, of species.
mown, some road contain pock-
sides are occasional portion oi tin .rretehol
\
I
support
herbs along the fencelmes lh sites spe-
ets of prairie rid reel in e
-
Eriogonum
including Astragalus Buglossoides arvensis,
cies distortus,
m cum Orbexilum Pen-
Eryngt m, latum, simplex,
longijolium, u vucetjolt u ivi h a
maxima
tcmou lan'ijhna R and Silphium radula.
in <Wis Uiiiliu
t I >
OSR county wildflower viewing
Roadsides along are the best places in the for
and summer.
in the spring
ome
Hit Ka\ ota IV will continue to host the most unique habitat
-r if
i
in Madison Count}' he wild stretch of south o\ ake milestone is allowed
if it
t I I
remain unimpouncled. The upper terraces along the consist deep
to rivet oi
spn
sands where a high water table produces my, a nil nearl v bog-like seeps. Here,
two springs supported a number of species not found elsewhere in the county:
Galium obtusum. tlvdnxoiylc ranunculoidesjuncus
Baccharis halimijolia,
Saccharum
Ranunculus baldwinii,
debilis,Polypogon mouspclicnsis. scclcral us.
Sagittariaplatyphxlla. and laxndium distich lows oi these springs have
urn. lie
I I
been altered by landowners to provide water lor livestock, but the habitat is
m
m p.m rounded by Myrica
and
rich unique nu h o h id a spi nig
still
i i
, ,
and Rubus argutus and harbored a few species typically associated with
cerifera
such hea Rhexia mat tana and b'uirena squarrosa.
true bogs, as Plan foetida,
and
Unfortunately, h)°° an v oat* d to u an small tank, the
in tin a \<
i i
<
may
unusual
hydrology not continue support these plants.
altered to
Numerous and oxbows found along Navasota River
natural lakes are the
m
Oxbows low woods near the river host several aquatic and terrestrial species
m
Some
rarely or never seen elsewhere the count}'. of liese are Didiplisdiandra,
t
and
pcnxOldcnlandia Sauru ruscernuus,
uncus
Eragrostishypnoidcs. re host
ii,
j
OSR
Utricularia radiata. Just south of on the Navasota River lies a string of
natural lakes in the open loodplam. These lakes have a unique flora differing
f
from that of the oxbow lakes, Species found in and around these lakes include
Nelumbo
americana,
Bacopa Eleocharis palustrisjusticia lutea,
rotundifolia,
Nuphar Sphenoclea zeylanica, and Zizianiopsis miliacea. Most of these
lutea,
water
species were found nowhere else in the county. Plants in these bodies of
somewhat
are protected Irom curious hotaiusts by snapping and
turtles nest-
ing
alligators.
The
Navasota River has created ancient high winch appear
river terraces,
as a series of hills that are easily seen from OSR. These have bald tops with
hi
lis
summit
a white sand ringed by scrubby Oak woods, and rocky with
Post sides
These
rich prairie-like pockets. unusual lulls host species with distinctly xenc,
pe< ie: n .trictcd to e\n\ in< In.i \rg< inane alhiflora,
'
li
l
bra, Croptilon ngulijaliuin, and Mirabihs Rivina
linearis.
mmit
one
of of these Species
hills.
only seen on the rocky hillsides include Loejlmgia and Opuntia
saiairrosd
The wa
humifusa. lath ivcred with tin cale insect U loinopi .occoidea.e)
r ra:(.
(
from which pigment The
the red cochineal isextracted. grassy areas of the hill-
side were the only Dalca eampaila conn
sites lor
in lie v
t t
In the northern portion o( the county are two creeks that drain into the
Cobb
Youngs and down
Trinity River, ireek Creek. These creeks have cut into
(
the ancient terrace sand, and mudstonc deep
ol clay, to iorrn canyons, creating
a landscape unlike thai in any other part of Madison County. lowever, the two
\
creeks have very different histories, and this is reflected in their floras. Youngs
Canyon
Creek formed
within 70
the past years as the result an excavation by
o'i
the owners an attempt and
in ro divert the creek reduce looding of the sur-
I
rounding cropland (Leon Wakefield, com The
pers. L997). easily eroded
in. soil
was washed down
quickly
to the ironstone bedrock, creating sculpted walls
more
than seven meters high, bizarre monolithic pinnacles of sandstone, and
The uncommon
waterfalls. surrounding land exhibits the Southern Red Oak -
Gum
Oak
Sweet
- Post association, but the canyon itself has not yet developed a
unique Only
twospeeies, llydnnvt urnhelhaa and
flora. Najasguadalupensis,
vie
bund
were solely Youngs Creek Canyon. Future monitoring
at of species
re-
cruitment canyon
at this easily accessible could provide an interesting study
ol colonization in a situation of unusual disturbance.
The Cobb
uplands around Creek are similar to those around Youngs Creek,
maze
but the of spring-led gullies and canyons wees created without human
interference. This locality supports a flora that is allied with that of northeast-
ern Texas and has produced
cveral peck range extensions. Species found only
along springs and low banksol CohhCreekme
Apiasamentana,Araliaspinosa,
Carex emoryi, Onoilea Quotas shumardir num and
sensihilis, Tr Utile walteri,
WaodwardiaarealaiaOne
very unusual thiscanvon wasa witha
habitat
at site
hanging garden on the canyon wal was continued some on
that in aspects the
I
The woods
cliff above. on the were mostly composed Quercus
cliff of
marilandica. Species found nowhere in the county other than this include
site
AreolariagrandiflorajLchiniiccaangustijoliajMLtucLi
hirsuta,Liatriselegans,
Osmunda
cinnamomea, and
Spiranthes tuherosa. Other species unique
to