ASSESSMENT OF INVASIVENESS AND ECOLOGICAL IMPACT OF NON-NATIVE PLANTS IN TEXAS

1
ASSESSMENT OF INVASIVENESS AND ECOLOGICAL
IMPACT OF NON-NATIVE PLANTS IN TEXAS

• Guy Nesom, Fort Worth
  
• Texas Invasive Plant and Pest
  Conference
• November 2009

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• Overview of non-native plant species in Texas
• which are here?
• which are the most damaging, the least?
• which are most likely to become widespread
  and damaging? (WATCH)
• which have the greatest possibility of
  being eradicated?
• which require more information for accurate
  evaluation? which damaging species
  are likely to enter Texas in the near future?
• (EXPECTED)
•  
• Perspectives useful in public awareness and in
  decisions toward efforts in prevention,
  detection, and control

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A documented account of 820 non-native species
reported to grow outside of cultivation in Texas
has been developed. est. 6000 total species
About 300 of these species have been reported
since the 1970 publication of the Manual of the
Vascular Plants of Texas -- each of these has
been documented by at least a literature
reference. A Fundamental Invasiveness Index
provides a framework for ranking of each of the
non-native species according to their
invasiveness and ecological impact. The Index
is based on knowledge of the species from field,
herbarium, and literature. The F1 category
(invasive in natural habitats and ecologically
damaging) includes 51 species. A Watch List
(those most likely to become F1) includes 60
species. A Super Watch List (a subset of the
Watch List, those with greatest potential to be
eradicated) includes 45 species. An Expected
List (species not yet in Texas but probably to
arrive soon, potentially to become F1) includes
25 species.
SUMMARY
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ACKNOWLEDGEMENTS

• The authenticity of this work, especially in
  evaluation of the F1 species and Watch List but
  also in discussion of concepts and other topics,
  owes to contributions from Jed Aplaca, Bill Carr,
  Norma Fowler, Laura Hansen, Stephan Hatch, Walter
  Holmes, Eric Keith, Barney Lipscomb, Andy
  McDonald, Barbara McRoberts, Michael McRoberts,
  Tom Patterson, Jackie Poole, Mike Powell, Nelson
  Rich, Monique Reed, David Rosen, Jason Singhurst,
  Bruce Sorrie, Damon Waitt, and Justin Williams.
• Detailed journal reviews by Jackie Poole, Damon
  Waitt, and Bruce Hoagland were valuable in
  refinement of the ranking protocols and the
  detailed commentaries by Jackie Poole on
  everything from A to Z was helpful and
  appreciated beyond expression.
• Barney Lipscomb, Editor of J. Bot. Res. Inst.
  Texas, helped in many ways, especially with
  literature and with planning of the publication.

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To be published as a manuscript in late Nov 2009
(J. Bot. Res. Inst. Texas)
The information is available online,
regularly updated
www.guynesom.com
The published manuscript will include
commentary on development of the complete list
commentary on the ranking categories for
Texas a brief review of other ranking
systems in the USA
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Citation for web files
Nesom, G.L., J.L. Aplaca, W.R. Carr, N.L. Fowler,
L.L. Hansen, S.L. Hatch, B.W. Hoagland, W.C.
Holmes, E.L. Keith, B.L. Lipscomb, B.R.
MacRoberts, M.H. MacRoberts, J.A. McDonald, T.F.
Patterson, J.M. Poole, A.M. Powell, N. Rich, M.D.
Reed, D.J. Rosen, J.R. Singhurst, B.A. Sorrie,
B.L. Turner, D.E. Waitt, and J.K. Williams.
2009. Non-native plants of Texas Overview of
occurrence and invasiveness assessments.
lthttp//www.guynesom.com/TexasNonnativeMENUweb.htm
gt
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Index Categories

• F1 Invasive in both disturbed and natural
  habitats, negatively affecting native species or
  natural biodiversity by altering native
  vegetation and habitats or by outcompeting or
  hybridizing with native species or, invasive
  into agricultural habitats and causing
  significant economic damage. Woody (17 species),
  Herbaceous (25 species), Aquatic (9 species),
  total 51
• F2 Abundant in number and widespread, commonly
  invasive in disturbed habitats, much less
  commonly in natural habitats.
• Woody (13 species),
  Herbaceous (229 species), Aquatic (16 species),
  total 258
• F3 Relatively few in number, known from
  relatively few localities, usually in disturbed
  habitats. Woody (76 species), Herbaceous (354
  species), total 424
• F4 Status unknown. (80 species)
• Watch List species with high potential to
  rapidly become destructive in Texas those most
  likely to warrant F1 ranking.
• Woody, Herbaceous, and
  Aquatic (60 species)
• Super Watch List (subset of Watch List) species
  with greatest potential to be eradicated. 45
  species

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For evaluation of an individual species,
knowledge is required of the following

• Nativity. Is the species native or non-native?
  
• Approximate date of introduction in Texas
  (e.g., pre-1970, 1970s, 1980s, 1990s).
  Documentation in the current account does not
  provide specific information for species
  introduced before 1970 (those included in Correll
  Johnstons Manual), but for species recorded
  since that time, dates are evident in a file
  posted and periodically updated on the internet.
  
•  
• Current geographic distribution. Based on
  distribution maps in Turner et al. (2003),
  distribution maps generated by data from Invaders
  of Texas (2009), records from herbaria, and
  literature accounts.
•  
• Ecological/reproductive behavior in Texas and
  in other regions. Based on field experience of
  the author and others, published literature, and
  information from herbarium collections.
•  
• Basic habitat and growth form (aquatic or
  terrestrial, herbaceous or woody). Based on
  field experience, published literature,
  information from herbarium collections.

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Caesalpinia mexicana
Native in Texas or spreading from
cultivation?
2003 Atlas
10
Chilopsis linearis
Native in south Texas, non-native in north
Texas?
2003 Atlas
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For evaluation of an individual species,
knowledge is required of the following

• Nativity. Is the species native or non-native?
  
• Approximate date of introduction in Texas
  (e.g., pre-1970, 1970s, 1980s, 1990s).
  Documentation in the current account does not
  provide specific information for species
  introduced before 1970 (those included in Correll
  Johnstons Manual), but for species recorded
  since that time, dates are evident in a
  documentation file posted and regularly updated
  on the internet.
•  
• Current geographic distribution. Based on
  distribution maps in Turner et al. (2003),
  EDDMapS distribution maps generated by data from
  Invaders of Texas (2009), records from herbaria,
  and literature accounts.
•  
• Ecological/reproductive behavior in Texas and
  in other regions. Based on field experience of
  the author and others, published literature, and
  information from herbarium collections.
•  
• Basic habitat and growth form (aquatic or
  terrestrial, herbaceous or woody). Based on
  field experience, published literature,
  information from herbarium collections.

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Documentation file on-screen view

• ARACEAE
• Colocasia esculenta (L.) Schott
• Arridge, R.E. and P.J. Fongteyn. 1981.
  Naturalization of Colocasia esculenta (Araceae)
  in the San Marcos River, Texas. Southw. Nat. 26
  210211.
• Dense stands of this species grow on the banks of
  the Blanco, Colorado, Guadalupe, and San Marcos
  rivers.
• This species is recorded from 6 counties, fide
  Turner et al. (2003). Jackie Poole (pers. comm.,
  July 2009) notes that it is under-represented in
  herbaria. Its at Lost Maples in Bandera County,
  and I dont doubt that its in many other Hill
  Country streams as well. The Invaders of Texas
  database and EDD Map show the species in 11
  counties Bexar, Brazoria, Guadalupe, Hardin,
  Harris, Hays, Liberty, Montgomery, Tarrant,
  Travis, and Valverde.
• Cryptocoryne beckettii Thwaites ex Trimen
• Rosen, D.J. 2000. Cryptocoryne beckettii
  (Araceae), a new aquatic plant in Texas. Sida
  19 399401.
• Hays Co. San Marcos River, as large naturalized
  colonies in open shallow riffles and shaded deep
  pools.
•  
• Pistia stratioides L.
• Included in the 1970 Texas Flora. Vouchered at
  TEX for 7 counties, but shown by Howard (2009) to
  occur in 10 discrete Texas drainage systems,
  clearly in at least 10 counties.
• Howard, V. 2009. Pistia stratiotes. USGS
  Nonindigenous Aquatic Species Database,
  Gainesville, FL. lthttp//nas.er.usgs.gov/queries/
  FactSheet.asp?speciesID1099.gt Revision Date
  3/14/2008
•  
• Xanthosoma sagittifolium (L.) Schott
• Lemke, D.E. and E.L. Schneider. 1988.
  Xanthosoma sagittifolium (Araceae) new to Texas.
  Southw. Nat. 33 498499.
• Hays Co. San Marcos River, growing with
  Colocasia esculenta. Guadalupe Co. Guadalupe
  River, near Seguin.
• ASCLEPIACEAE
• Cryptostegia grandiflora (Roxb. ex R. Br.) R. Br.

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Non-native plants of Texas
  Fundamental Invasive Index INDEX
CATEGORIES   All species, with Invasive Index
rankings COMPLETE LIST   All aquatic
species, grouped by Invasive Index ranking ALL
AQUATIC Numbers
of non-native species in Texas ranked as F1, F2,
F3, and F4. The total is 820 species.
Species ranked as F1 F1 Species ranked as
F2 F2 Watch List WATCH Expected List
EXPECTED Non-native Texas species on lists
from nearby states and regions RANKED NEARBY
Non-native species reported for Texas since
1970 DOCUMENTATION
CITATION
on-screen view www.guynesom.com
on-screen view www.guynesom.com
F1 Woody Herbaceous Aquatic TOTAL 17
25 9 51 F2
Woody Herbaceous Aquatic TOTAL 13
229 16 258 F3 Woody
Herbaceous TOTAL 76
354 424 F4
Woody Herbaceous TOTAL
0 80 80
Comments, suggestions, and questions about any of
these lists, rankings, or concepts are sought and
welcomed. Post and read comments in blog format.
BLOG
Last update 14 Oct 2009
14
Complete Liston-screen view
Non-native Species In Texas Complete List  
All known non-native species (terrestrial and
aquatic) that occur in Texas are listed here,
organized by family. 820 species are included.
Each species is ranked on the Fundamental
Invasiveness Index developed for Texas species.
Documentation for additions since 1970 is in a
separate file Non-native species naturalized in
Texas Reported since 1970. Last update 3
October 2009 ACANTHACEAE Hygrophila
polysperma (Roxb.) T. Anders.
F2-AquaticNomaphila stricta (Vahl) Nees
F2-AquaticRuellia caerulea Morong
F3-Herbaceous SYN Ruellia brittoniana
LeonardThunbergia alata Bojer ex Sims
F3-HerbaceousALOACEAE Aloe vera (L.) Burm.
f. F3-HerbaceousAMARANTHACEAE
Achyranthes aspera L. F3-HerbaceousAlternant
hera caracasana Kunth F2-HerbaceousAlternanther
a philoxeroides (Mart.) Griseb. F1-Aquatic
Alternanthera pungens Kunth F3-HerbaceousAlter
nanthera tenella Colla F3-Herbaceous
SYN Alternanthera bettzichiana (Regel.) Standl.
Amaranthus blitum L. F2-Herbaceous
SYN Amaranthus viridus auct. non L.Amaranthus
cruentus L. F3-Herbaceous SYN
Amaranthus hybridus var. cruentus (L.)
Moq.Amaranthus hypochondriacus L.
F3-HerbaceousAmaranthus sessilis (L.)
DC. F4-HerbaceousCelosia argentea L.
F3-HerbaceousGomphrena globosa L.
F2-Herbaceous
to end of file, families A-Z
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Non-native plants of Texas
  Fundamental Invasive Index INDEX
CATEGORIES   All species, with Invasive Index
rankings COMPLETE LIST   All aquatic
species, grouped by Invasive Index ranking ALL
AQUATIC Numbers
of non-native species in Texas ranked as F1, F2,
F3, and F4. The total is 820 species.
Species ranked as F1 F1 Species ranked as
F2 F2 Watch List WATCH Expected List
EXPECTED Non-native Texas species on lists
from nearby states and regions RANKED NEARBY
Non-native species reported for Texas since
1970 DOCUMENTATION
CITATION
on-screen view www.guynesom.com
on-screen view www.guynesom.com
F1 Woody Herbaceous Aquatic TOTAL 17
25 9 51 F2
Woody Herbaceous Aquatic TOTAL 13
229 16 258 F3 Woody
Herbaceous TOTAL 76
354 424 F4
Woody Herbaceous TOTAL
0 80 80
Comments, suggestions, and questions about any of
these lists, rankings, or concepts are sought and
welcomed. Post and read comments in blog format.
BLOG
Last update 14 Oct 2009
16
All non-native aquatic species known in Texas

• F1 Known to occur in 10 or more counties
• F2 Known to occur in 9 or fewer counties
• (number of counties of known occurrence
  in parenthesis)

F1-AQUATIC (9 species) Alternanthera
philoxeroides (20) Colocasia esculenta
(11) Eichhornia crassipes (25) Hydrilla
verticillata (85) Myriophyllum aquaticum
(18) Myriophyllum spicatum (10) Nasturtium
officinale (35) Pistia stratiotes (10 or
more) Salvinia molesta (10)
F2-AQUATIC (16 species) Ceratopteris
thalictroides (1) Cryptocoryne beckettii
(1) Egeria densa (3) Hydrocleys nymphoides (1
or few) Hygrophila polysperma (2) Landoltia
punctata (6) Limnophila sessiliflora
(2) Ludwigia grandiflora subsp. grandiflora
(3) Ludwigia grandiflora subsp. hexapetala
(9) Nomaphila stricta (1) Nymphoides indica
(1) Nymphoides peltata (2) Ottelia alismoides
(1) Potamogeton crispus (8) Salvinia minima
(2) Xanthosoma sagittifolium (2)
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Colocasia esculenta
Naturalizing mostly around urban areas.
2003 Atlas
Early Detection and Distribution Mapping System
observations from Invaders of Texas database
2009 EDDMapS
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F1 Rankings Woody and Herbaceous
F1 WOODY Ailanthus altissima Arundo donax
Ligustrum lucidum Ligustrum quihoui
Ligustrum sinense Lonicera japonica Melia
azedarach Nandina domestica Rosa bracteata
Rosa multiflora Tamarix aphylla Tamarix
chinensis (including T. pentandra, T.
ramosissima) Tamarix gallica (including T.
canariensis, T. africana) Tamarix parviflora
Triadica sebifera Ulmus pumila Wisteria
sinensis
F1 HERBACEOUS Atriplex semibaccata Bassia
scoparia Bothriochloa ischaemum var. songarica
Carduus nutans subsp. macrocephalus
Centaurea melitensis Cynodon dactylon
Cyperus entrerianus Dichanthium annulatum
Dichanthium aristatum Dichanthium sericeum
Eragrostis lehmanniana Lolium perenne
Lygodium japonicum Marrubium vulgare
Melilotus albus Melilotus indicus
Melilotus officinalis Orobanche ramosa
Pennisetum ciliare Rapistrum rugosum Salsola
kali subsp. pontica Salsola tragus Solanum
viarum Sorghum halepense Urochloa maxima

Invasive in both disturbed and natural habitats,
negatively affecting native species or natural
biodiversity by altering native vegetation and
habitats or by outcompeting or hybridizing with
native species
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F2 Rankings Woody and Herbaceous
F2 WOODY Albizia julibrissin
Broussonetia papyrifera Hypericum perforatum
Lagerstroemia indica Lantana camara Morus
alba Nicotiana glauca Phyllostachys aurea
Poncirus trifoliata Pueraria montana var.
lobata Pyrus calleryana Rosa laevigata Vitex
agnus-castus
F2 HERBACEOUS 228 species
Abundant in number and widespread, commonly
invasive in disturbed habitats, much
less commonly in natural habitats.
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Watch list non-native species in Texas
potentially ranked as F1
from F2-AQUATIC Ceratopteris thalictroides
Cryptocoryne beckettii Egeria densa Hydrocleys
nymphoides Hygrophila polysperma Landoltia
punctata Limnophila sessiliflora Ludwigia
grandiflora subsp. grandiflora Ludwigia
grandiflora subsp. hexapetala Nomaphila
stricta Nymphoides indica Nymphoides peltata
Ottelia alismoides Potamogeton crispus
Salvinia minima Xanthosoma sagittifolium
from F2-WOODY Hypericum perforatum Pueraria
montana var. lobata Pyrus calleryana Vitex
agnus-castus
from F2-HERBACEOUS Carduus tenuiflorus Cirsium
vulgare Clematis terniflora Gibasis pellucida
Lespedeza cuneata Perilla frutescens
Polygonum arenastrum Polygonum persicaria
Stachys floridana Torilis arvensis Verbena
brasiliensis
from F3-WOODY Ardisia crenata Casuarina
equisetifolia Cinnamomum camphora Cortaderia
selloana Elaeagnus angustifolia Leucaena
leucocephala Lonicera maackii Macfadyena
unguis-cati Photinia serratifolia Pistacia
chinensis Schinus molle Schinus
terebinthifolius Ulmus parvifolia
from F3-HERBACEOUS Carduus acanthoides Cayratia
japonica Cryptostegia grandiflora Elymus
repens Imperata cylindrica Lespedeza
bicolor Microstegium vimineum

• Known in Texas only from a few recently recorded
  populations and known to be both invasive and
  ecologically destructive in other regions of the
  USA or the world. A number of additional F3
  species, especially the woody ones, and some of
  those ranked as F4 (status unknown) probably
  belong on the Watch List.

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Cryptostegia grandiflora Watch List
Rubber vine is smothering riverine forests in the
dry tropics of north Queensland (northeast
Australia), especially along rivers feeding into
the Gulf of Carpentaria. It is arguably
Australia's worst weed.
- Invasive Species
Council of Australia
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Super Watch List -- What is realistic?
The Watch List account perhaps is the most
significant part of the overview of Texas
non-native native plants provided here.
F1s and many of the F2s are already so widespread
that it is unlikely that they can be eradicated
or even controlled except by sustained efforts on
local levels. Biological control? Many of the
Watch List species especially widely
cultivated woody species -- also probably are
beyond eradication. Control by limiting further
planting?
All of the F2 aquatics are included because of
their potential for extremely rapid dispersal and
growth, but at least some of them are beyond
eradication.
Super Watch List (subset of the Watch List)
those species that perhaps can be removed from
the Texas landscape before they become impossible
to control. Immediate attention should go to
these.
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Super Watch List
From F1-HERBACEOUS   Solanum viarum -- attempt
to eradicate (but becoming locally abundant)
  From F2-WOODY   Hypericum perforatum --
attempt to eradicate Pueraria montana var.
lobata -- attempt to eradicate from F3-WOODY
  Ardisia crenata -- attempt to eradicate
Casuarina equisetifolia -- attempt to
eradicate Cinnamomum camphora -- attempt to
eradicate (but commonly cultivated) Elaeagnus
angustifolia -- attempt to eradicate Leucaena
leucocephala -- attempt to eradicate Lonicera
maackii -- attempt to eradicate (but becoming
locally abundant) Macfadyena unguis-cati --
attempt to eradicate Schinus terebinthifolius
-- attempt to eradicate   from F2-HERBACEOUS
  Clematis terniflora -- attempt to eradicate
(but becoming locally abundant) Gibasis
pellucida -- attempt to eradicate Lespedeza
cuneata -- attempt to eradicate (but becoming
locally abundant)   from F3-HERBACEOUS
Cayratia japonica -- attempt to
eradicate Cryptostegia grandiflora -- attempt
to eradicate Imperata cylindrica -- attempt to
eradicate Microstegium vimineum -- attempt to
eradicate
from F2-AQUATIC   Ceratopteris thalictroides
Colocasia esculenta Cryptocoryne beckettii
Egeria densa Hydrocleys nymphoides
Hygrophila polysperma Landoltia punctata
Limnophila sessiliflora Ludwigia grandiflora
subsp.
grandiflora Ludwigia grandiflora
subsp. hexapetala Nomaphila stricta
Nymphoides indica Nymphoides peltata
Ottelia alismoides Potamogeton crispus
Salvinia minima Xanthosoma sagittifolium
All F2 Aquatics included because of
their potential for extremely rapid
dispersal and growth.
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Watch List, annotated
from F1-HERBACEOUS  Solanum viarum --
attempt to eradicate (but becoming locally
abundant) from F2-WOODY Hypericum perforatum
-- attempt to eradicate Pueraria
montana var. lobata -- attempt to eradicate
Pyrus calleryana --
widely cultivated, probably here to stay and
increaseVitex agnus-castus
-- widely cultivated, probably here to stay and
increase from F3-WOODY Ardisia crenata
-- attempt to eradicate Casuarina
equisetifolia -- attempt to eradicate
Cinnamomum camphora -- attempt to eradicate
(but commonly cultivated) Elaeagnus
angustifolia -- attempt to eradicate
Leucaena leucocephala -- attempt to
eradicate Lonicera maackii --
attempt to eradicate (but becoming locally
abundant) Macfadyena unguis-cati --
attempt to eradicate Photinia serratifolia
-- widely cultivated, probably here to
stay and increasePistacia chinensis
-- widely cultivated, probably here to stay
and increasePyracantha koidzumii --
attempt to eradicate Schinus molle
-- widely cultivated, probably here to
stay and increaseSchinus terebinthifolius
-- attempt to eradicate Ulmus parvifolia
-- widely cultivated, probably here to
stay and increase from F2-HERBACEOUS Carduus
tenuiflorus -- already abundant, at least
locally, probably here to stay and
increaseCirsium vulgare --
already abundant, at least locally, probably here
to stay and increaseClematis terniflora
-- attempt to eradicate (but becoming locally
abundant) Gibasis pellucida --
attempt to eradicateLespedeza cuneata
-- attempt to eradicate (but becoming locally
abundant) Perilla frutescens --
already abundant, at least locally, probably here
to stay and increasePolygonum arenastrum --
already abundant, at least locally, probably here
to stay and increasePolygonum persicaria --
already abundant, at least locally, probably here
to stay and increaseStachys floridana
-- already abundant, at least locally, probably
here to stay and increaseTorilis arvensis
-- already abundant, at least locally,
probably here to stay and increaseVerbena
brasiliensis -- already abundant, at
least locally, probably here to stay and increase
from F2-AQUATIC Ceratopteris thalictroides
-- attempt to control and eradicate Colocasia
esculenta -- attempt to control and eradicate
Cryptocoryne beckettii -- attempt to control
and eradicate Egeria densa -- attempt to
control and eradicate Hydrocleys nymphoides
-- attempt to control and eradicate Hygrophila
polysperma -- attempt to control and eradicate

(but becoming locally abundant)
Landoltia punctata -- attempt to control and
eradicate Limnophila sessiliflora -- attempt
to control and eradicate Ludwigia grandiflora
subsp. grandiflora -- attempt to control

and eradicate
Ludwigia grandiflora subsp. hexapetala --
attempt to control

and eradicate Nomaphila stricta
-- attempt to control and eradicate Nymphoides
indica -- attempt to control and eradicate
Nymphoides peltata -- attempt to control and
eradicate Ottelia alismoides -- attempt to
control and eradicate Potamogeton crispus --
attempt to control and eradicate Salvinia
minima -- attempt to control and eradicate
Xanthosoma sagittifolium -- attempt to control
and eradicate
Super Watch list
from F3-HERBACEOUS Cayratia japonica
-- attempt to eradicateCryptostegia
grandiflora -- attempt to eradicate Imperata
cylindrica -- attempt to eradicate
Microstegium vimineum -- attempt to
eradicate
25
Non-native plants of Texas
  Fundamental Invasive Index INDEX
CATEGORIES   All species, with Invasive Index
rankings COMPLETE LIST   All aquatic
species, grouped by Invasive Index ranking ALL
AQUATIC Numbers
of non-native species in Texas ranked as F1, F2,
F3, and F4. The total is 820 species.
Species ranked as F1 F1 Species ranked as
F2 F2 Watch List WATCH Expected List
EXPECTED Non-native Texas species on lists
from nearby states and regions RANKED NEARBY
Non-native species reported for Texas since
1970 DOCUMENTATION
CITATION
on-screen view www.guynesom.com
on-screen view www.guynesom.com
F1 Woody Herbaceous Aquatic TOTAL 17
25 9 51 F2
Woody Herbaceous Aquatic TOTAL 13
229 16 258 F3 Woody
Herbaceous TOTAL 76
354 424 F4
Woody Herbaceous TOTAL
0 80 80
Comments, suggestions, and questions about any of
these lists, rankings, or concepts are sought and
welcomed. Post and read comments in blog format.
BLOG
Last update 14 Oct 2009
26
Expected List
Alliaria petiolata (Garlic mustard)  
Ampelopsis brevipedunculata (Porcelain berry).
Berberis thunbergii (Japanese barberry)
Celastrus orbiculatus (Oriental bittersweet)
Centaurea stoebe (Spotted knapweed) Centaurea
solstitialis (Yellow star thistle) Cirsium
arvense (Canada thistle) Dioscorea alata
(Winged yam) Elaeagnus pungens (Thorny olive)
Elaeagnus umbellata (Autumn olive)
Euonymus alatus (Burning bush) Euonymus
fortunei (Wintercreeper) Euphorbia esula
(Leafy spurge) Halogeton glomeratus
(Saltlover)
Lonicera morrowii (Morrow's honeysuckle)
Lygodium microphyllum (Small-leaf climbing fern)
Melaleuca quinquenervia (Paperbark)
Miscanthus sinensis (Chinese silvergrass) Phalari
s aquatica (Harding grass) Pennisetum
setaceum (Fountain grass) Polygonum cuspidatum
(Japanese knotweed) Schismus arabicus
(Arabian schismus) Setaria faberi (Japanese
bristlegrass) Typha angustifolia (Narrowleaf
cattail) Wisteria floribunda (Japanese wisteria)
Not currently known (with certainty) in Texas but
occuring in nearby areas. Each is aggressively
invasive and ecologically damaging, and there is
a high probability that each soon will reach
Texas. More to be added.
27
Non-native Texas species on lists from nearby
states and regions
Terrestrial non-native species known to occur in
Texas assessed as invasive and/or with ecological
impact elsewhere in the United States. Bold
names are on the Texas F1 list. TEN --
Tennessee Exotic Pest Plant Council (ranks 1, 2,
3) FLA -- Florida Exotic Pest Plant Council
2007 (ranks 1, 2) SST -- Miller, J., E.
Chambliss, and C. Bargeron. 2004. Invasive
Plants of the Thirteen Southern States, a
compilation of invasive plants listed by any of
the 13 Southern States and those by federal
agencies pertaining to these States as of May
2004 CAL -- California Invasive Plant Council
AZ -- Arizona Wildlands Invasive Non-Native
Plant List (ranks high, medium, low). 2005.
Invasive Non-native plants that threaten
wildlands in Arizona A categorized list
developed by the Arizona Wildlands Invasive Plant
Working Group
Acroptilon repens CAL, AZ-high Aegilops
cylindrica AZ-low Agrostemma githago
SST Ailanthus altissima TEN1, SST, CAL Aira
caryophyllea CAL Ajuga reptans SST Albizia
julibrissin TEN1, SST Albizia lebbeck FLA1,
SST Alhagi maurorum CAL, AZ-med Alternanthera
philoxeroides TEN2, FL2, SST, CAL Anthemis
cotula CAL Anthoxanthum odoratum SST,
CAL Antigonon leptopus FLA2
Arctium minus SST Ardisia crenata FLA1,
SST Arenaria serpyllifolia SST Arthraxon
hispidus TEN2, SST Arundo donax AZhigh, SST,
TEN3, CAL Asphodelus fistulosus CAL,
AZ-low Atriplex semibaccata CAL Avenua fatua
CAL, AZ-med Bassia hyssopifolia CAL Bassia
scoparia CAL Bellardia trixago CAL Bothriochloa
ischaemum var. songarica TEN2, SST, CAL
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Non-native plants of Texas
  Fundamental Invasive Index INDEX
CATEGORIES   All species, with Invasive Index
rankings COMPLETE LIST   All aquatic
species, grouped by Invasive Index ranking ALL
AQUATIC Numbers
of non-native species in Texas ranked as F1, F2,
F3, and F4. The total is 820 species.
Species ranked as F1 F1 Species ranked as
F2 F2 Watch List WATCH Expected List
EXPECTED Non-native Texas species on lists
from nearby states and regions RANKED NEARBY
Non-native species reported for Texas since
1970 DOCUMENTATION
CITATION
on-screen view www.guynesom.com
on-screen view www.guynesom.com
F1 Woody Herbaceous Aquatic TOTAL 17
25 9 51 F2
Woody Herbaceous Aquatic TOTAL 13
229 16 258 F3 Woody
Herbaceous TOTAL 76
354 424 F4
Woody Herbaceous TOTAL
0 80 80
Comments, suggestions, and questions about any of
these lists, rankings, or concepts are sought and
welcomed. Post and read comments in blog format.
BLOG
Last update 14 Oct 2009
29
Documentation file on-screen view

• ASTERACEAE
• Cnicus benedictus L.
• Jones, S.D., J.K. Wipff, and P.M. Montgomery.
  1997. Vascular plants of Texas A comprehensive
  checklist including synonymy, bibliography, and
  index.
• Listed by Jones et al. (1997) included
  in the Texas distribution by Keil and Ochsmann
  (2006), apparently on the basis of the Jones et
  al. listing Roadsides, fields, waste places,
  sometimes cultivated N.B., N.S., Ont. Ala.,
  Ariz., Ark., Calif., Conn., Fla., Ga., Ill., Md.,
  N.J., N.Y., N.C., Oreg., S.C., Tenn., Tex., Utah,
  Va., Wash., Wis. The Texas record apparently
  is based on the following Callahan Co. grown
  in a pot from a wheat field, Mar 1993, J.
  Landers s.n. (TAES). The plant apparently was
  grown to identify a weed submitted for
  identification. Thanks to Steve Hatch for the
  voucher information.
•  
• Cotula australis (Sieber ex Spreng.) Hook. f.
• Recorded by Johnston (1990) based on
  plants from the Texas AM campus, as documented
  here by collections at TEX the report by Hatch
  et al. (1990) probably based on the same or
  similar collections.
• Brazos Co. College Station, campus of
  AM University, lawn weed with Soliva, 27 Apr
  1970, Correll Correll 38493 (LL, TEX) Texas
  AM University campus, an Australian weed widely
  adventive in W hemisphere, the first population
  known in Texas, 23 Apr 1970, Johnston s.n. (TEX).
  
•  
• Cosmos bipinnatus Cav.
• Brown, L.E., E.L. Keith, D.J. Rosen, and J.
  Liggio. 2007. Notes of the flora of Texas with
  additions and other significant records. III. J.
  Bot. Res. Inst. Texas 1 12551264.
• Harris, Polk cos. Plants of this
  species rarely persist for more than one growing
  season but are often re-seeded for roadside
  beautification.

30
Documentation file on-screen view

• DIOSCORIDACEAE
• Dioscorea bulbifera L.
• Correll, D.S. 1972. Manual of the Vascular
  Plants of Texas I. Additions and corrections.
  Amer. Midl. Nat. 88 490496.
• Eastern Texas.
• Hatch et al. (1990), as listed.
• No voucher at TEX.
•  
• Dioscorea oppositifolia L.
• Johnston (1990) noted that There is a
  possibility that D. oppositifolia also occurs in
  Texas (for nomenclature and character-states see
  Al-Shehbaz Schubert 1989). The species is
  included for Texas by the PLANTS Database on the
  basis of the Johnston (1990) allusion, but no
  vouchers have been seen and the species is
  excluded from the Texas flora.  
• DIPSACACEAE
• Dipsacus fullonum L.
• Singhurst, J.R. and W.C. Holmes. 2000. Dipsacus
  fullonum (Dipsacaceae) and Verbesina walteri
  (Asteraceae), new to Texas. Sida 19 723725.
• Collin Co.
•  
• Scabiosa atropurpurea L.
• Hatch et al. (1990), as listed. Vouchered at
  TEX for Collin, Hunt, Lamar, and Rockwall
  counties.
•  
• DRYOPTERIDACEAE

31
Documentation file on-screen view

• VERBENACEAE
• Clerodendrum bungei Steud.
• Hatch et al. (1990), as listed.
•  
• Clerodendrum indicum (L.) Kuntze
• Hatch et al. (1990), as listed.
•  
• Duranta erecta L.
• Hatch et al. (1990), as listed.
•  
• Glandularia hybrida (Grönland Rümpler) Nesom
  Pruski
• Hatch et al. (1990), as listed.
•  
• Verbena litoralis Kunth
• Hatch et al. (1990), as listed.
•  
• Vitex negundo L.
• Hatch et al. (1990), as listed.
•  

32
To do (most immediate)
For 109 species added from undocumented floristic
lists by Hatch et al.
(1990), Johnston (1990), etc provide
documentation -- vouchers and other information
For each F1 species and Watch List species
add/upgrade documentation for geographic
distribution provide a brief narrative
regarding invasiveness and ecological impact
in Texas Expected List evaluate
regionally near-by species for additions to Texas
list
Continuing Evaluations, re-evaluations
Coordination with Oklahoma, Arkansas, and
Louisiana