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

ASSESSMENT OF INVASIVENESS

AND ECOLOGICAL IMPACT

OF NON-NATIVE PLANTS IN TEXAS

Guy Nesom, Fort Worth

Texas Invasive Plant and Pest Conference

November 2009

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

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

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.

To be published as a manuscript in late Nov 2009 (J. Bot. Res. Inst. Texas)

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

The information is available online, regularly updated www.guynesom.com

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. <http://www.guynesom.com/TexasNonnativeMENUweb.htm>

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

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 & Johnston’s “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.

Caesalpinia mexicanaNative in Texas or spreading from cultivation?

2003 Atlas

Chilopsis linearis

Native in south Texas,

non-native in north Texas?

2003 Atlas

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 & Johnston’s “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.

Documentation file: on-screen view

ARACEAE * Colocasia esculenta (L.) SchottArridge, R.E. and P.J. Fongteyn. 1981. Naturalization of Colocasia esculenta (Araceae) in the San Marcos River, Texas. Southw. Nat.

26: 210–211. 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. It’s at Lost Maples in Bandera County, and I don’t doubt that it’s 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: 399–401. 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.

<http://nas.er.usgs.gov/queries/FactSheet.asp?speciesID=1099.> Revision Date: 3/14/2008 * Xanthosoma sagittifolium (L.) SchottLemke, D.E. and E.L. Schneider. 1988. Xanthosoma sagittifolium (Araceae) new to Texas. Southw. Nat. 33: 498–499. Hays Co. San Marcos River, growing with Colocasia esculenta. Guadalupe Co. Guadalupe River, near Seguin.

ASCLEPIACEAECryptostegia grandiflora (Roxb. ex R. Br.) R. Br.Patterson, T.F. and G.L. Nesom. 2009. Cryptostegia grandiflora (Asclepiadaceae), a new non-native weed for Texas. J. Bot. Res. Inst.

Texas 3: 461– 463. Starr Co. Two localities along the Rio Grande; it is abundant at both sites and often densely covers entire trees. This species has been

described by the Australian Invasive Species Council as “arguably Australia's worst weed.”

* 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


* 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

F1 Woody Herbaceous Aquatic TOTAL 17 25 9 51


F3 Woody Herbaceous TOTAL 76 354 424


Non-native plants of Texas[on-screen view]

www.guynesom.com

[on-screen view]

www.guynesom.com

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

Complete List:[on-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-Herbaceous

ALOACEAE Aloe vera (L.) Burm. f. F3-Herbaceous

AMARANTHACEAE Achyranthes aspera L. F3-HerbaceousAlternanthera caracasana Kunth F2-HerbaceousAlternanthera philoxeroides (Mart.) Griseb. F1-Aquatic Alternanthera pungens Kunth F3-HerbaceousAlternanthera 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







* Watch List WATCH









www.guynesom.com

[on-screen view]

www.guynesom.com




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)

Colocasia esculentaNaturalizing mostly around urban areas.

2003 Atlas

2009 EDDMapS

Early Detection and Distribution Mapping System – observations from Invaders of Texas database

F1 Rankings – Woody and Herbaceous

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

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

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 …

F2 Rankings – Woody and Herbaceous

F2 HERBACEOUS

228 species

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

Abundant in number and widespread, commonly invasive in disturbed habitats, much less commonly in natural habitats.

Watch list: non-native species in Texas potentially ranked as F1

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.

from F2-WOODY:

Hypericum perforatum

Pueraria montana var. lobata

Pyrus calleryana

Vitex agnus-castus

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 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 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 F3-HERBACEOUS:

Carduus acanthoides

Cayratia japonica

Cryptostegia grandiflora

Elymus repens

Imperata cylindrica

Lespedeza bicolor

Microstegium vimineum

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

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.

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.

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

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.

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 increase*Schinus 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 increase*Clematis terniflora -- attempt to eradicate (but becoming locally abundant) *Gibasis pellucida -- attempt to eradicate*Lespedeza 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 eradicate*Cryptostegia grandiflora -- attempt to eradicate *Imperata cylindrica -- attempt to eradicate *Microstegium vimineum -- attempt to eradicate







* Watch List WATCH









www.guynesom.com

[on-screen view]

www.guynesom.com




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)

Phalaris 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.

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-highAegilops cylindrica AZ-lowAgrostemma githago SSTAilanthus altissima TEN1, SST, CALAira caryophyllea CALAjuga reptans SSTAlbizia julibrissin TEN1, SSTAlbizia lebbeck FLA1, SSTAlhagi maurorum CAL, AZ-medAlternanthera philoxeroides TEN2, FL2, SST, CALAnthemis cotula CALAnthoxanthum odoratum SST, CALAntigonon leptopus FLA2

Arctium minus SSTArdisia crenata FLA1, SSTArenaria serpyllifolia SSTArthraxon hispidus TEN2, SSTArundo donax AZhigh, SST, TEN3, CALAsphodelus fistulosus CAL, AZ-lowAtriplex semibaccata CALAvenua fatua CAL, AZ-medBassia hyssopifolia CALBassia scoparia CALBellardia trixago CALBothriochloa ischaemum var. songarica TEN2, SST, CAL







* Watch List WATCH









www.guynesom.com

[on-screen view]

www.guynesom.com





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 A&M 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 A&M University, lawn weed with Soliva, 27 Apr 1970, Correll & Correll 38493 (LL, TEX); Texas A&M 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: 1255–1264.

Harris, Polk cos. “Plants of this species rarely persist for more than one growing season but are often re-seeded for roadside beautification.”


DIOSCORIDACEAE

* Dioscorea bulbifera L.

Correll, D.S. 1972. Manual of the Vascular Plants of Texas: I. Additions and corrections. Amer. Midl. Nat. 88: 490–496.

“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: 723–725.

Collin Co.

* Scabiosa atropurpurea L.

Hatch et al. (1990), as listed. Vouchered at TEX for Collin, Hunt, Lamar, and Rockwall counties.

DRYOPTERIDACEAE

* Cyrtomium falcatum (L. f.) Presl

Brown L.E. and K.N. Gandhi. 1989. Notes on the flora of Texas with additions, range extensions, and one correction. Phytologia 67: 394–399.

Harris Co.; naturalized plants on bank of Langham Creek, west of Houston.


VERBENACEAE

* Clerodendrum bungei Steud.


* Clerodendrum indicum (L.) Kuntze


* Duranta erecta L.


* Glandularia ×hybrida (Grönland & Rümpler) Nesom & Pruski


* Verbena litoralis Kunth


* Vitex negundo L.


VIOLACEAE

* Viola tricolor L.

Hatch et al. (1990), as listed. A voucher at TEX explicitly is from a cultivated plant. Excluded from the Texas flora.

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

ContinuingEvaluations, re-evaluations

Coordination with Oklahoma, Arkansas, and Louisiana

Documents

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