Printer Friendly

Invasive species in an urban flora: history and current status in Indianapolis, Indiana.

INTRODUCTION

An invasive species is defined in the United States by Executive Order as "a species that is: 1) non-native (or alien) to the ecosystem under consideration and 2) whose introduction causes or is likely to cause economic or environmental harm or harm to human health" (USDA, NISIC 2016). Invasive species (exotic insects, plants, fish, birds, mammals, and many other organisms) are a serious threat, resulting in estimated costs and damages of more than $120 billion annually in the United States (Pimental et al. 2005) and more than 12[euro] billion annually in Europe (van Ham et al. 2013). Human actions are the primary means of introduction.

Urban areas are often points of introduction for invasives (Pysek 1998). In cities, invasive plants have been shown to alter species composition, resulting in loss of biodiversity and declines in primary productivity, to diminish ecosystem services (e.g., erosion control), to cause infrastructure deterioration, to alter nutrient cycling, and to contribute to declines in property value (van Ham et al. 2013). Additional social impacts include the perception of spaces overgrown with invasives as signs of urban decay, and loss of visual connection with natural features such as riparian corridors (van Ham et al. 2013).

This paper reports on invasive plants known to be present in Indianapolis/Marion County, Indiana, USA. The city and the county are the same governmental unit and so occupy the same geographic space, referred to as Indianapolis in this paper. Indianapolis is a model urban area to study invasive plants for several reasons. Much is known about its floristic composition, from the late 1800s through current times. Indianapolis was almost entirely forested in pre-European presettlement times, but forests were reduced to 13% cover by the late 1900s (Barr et al. 2002). Most of the original forest was converted into row-crop agriculture. Agriculture has declined from 80% of land use in 1922 to 72% in 1953, to 18% by 1990 (http:www.savi.org). The time period from 1953-1990 corresponds with rapid urbanization in the city. This pattern of land use change is likely a model for other cities in the American Midwest. Indianapolis is the twelfth largest city in the United States, with an estimated population of over 900,000 people and total area of 650 [km.sup.2] (105,200 ha). The city is in the Central Till Plain Natural Region of Indiana (Homoya et al. 1985), an area characterized by a terrain of gently rolling hills of glacial till.

Species richness of the Indianapolis flora has been documented by Dolan et al. (2011) at about 700 plants. This number was consistent over a 70 year period, but there has been considerable species turn-over, with a loss of rare native plants and an increase in non-native plants from 20.3% to 27.1 % of the flora over the years covered by the study. These percentages are on par with urban areas across the globe (La Sorte et al. 2014). Not all non-natives in the Indianapolis flora, historically or currently, are considered invasive plants in Indiana (Indiana Invasive Species Council 2016). This report focuses upon invasive species in the Indianapolis flora, including how long they have been known to be present, their origins, and uses or causes of introduction. Finally, the invasive species that are likely to be the biggest problems in the near future for the city are discussed.

METHODS

For this study, plants were identified as invasive if they were present on the Official Indiana Invasive Plant list, established by the Indiana Invasive Species Council (2016). Nomenclature is based on scientific names used in that list. Sources of information on invasives present in the flora of Indianapolis and dates of first record range from historical journal articles to contemporary web-based records. The oldest record is a county list for Marion and adjacent Hamilton County (Wilson 1895). While not comprehensive, this paper does document species presence, often annotated with comments on abundance. Coulter (1899) produced a state-wide flora that sometimes mentions counties and ranges for plants now recognized as invasives in the state.

Deam's 1940 Flora of Indiana is the last comprehensive manual of the state's plants. Deam's flora presents county-level distribution maps based on herbarium specimen vouchers. Overlease & Overlease (2007) reported weed species distributions for Indiana at the county level, based on their own observations and compared these distributions with records from Deam (1940) and Coulter (1899). Dolan et al. (2011) compiled these and other records, including herbarium specimens (Figs. 1 & 2) from the Friesner Herbarium (BUT) of Butler University, into a historical list for the city (pre-1940) and a more recent list based on species reported by botanists working in the city since that time.

Additional records for invasives in Indianapolis came from the Indiana Plant Atlas (Dolan & Moore 2016), sorted by location (Marion County) and invasiveness, and from Early Detection & Distribution Mapping System (EDDMapS 2016). Origin and mode of introduction of invasives are from Weber (2003) and Czarapata (2005).

Invasive plants that represent the largest current and emerging threats in the city were identified by polling local experts. Eight environmental professionals and knowledgeable amateurs from government agencies, non-profit organizations, private consulting firms, and academia were asked to list the invasive plants they perceive as being the greatest current and emerging concerns in Indianapolis.

RESULTS AND DISCUSSION

Sixty-nine of the 120 species listed on the Official Invasive Plant List for Indiana are known to occur in Indianapolis. These invasives comprise approximately 10% of the flora, somewhat less than the 16% average reported for 110 cites by La Sorte et al. (2014). The majority of invasive plants reported for Indianapolis are ranked as highly invasive (Fig. 3). Most plants (62%) originated in Asia or Eurasia (Fig. 4). Escape from cultivation is, by a wide margin, the most common mode of introduction of invasives in Indianapolis (Fig. 5). Accidental or unknown modes of introduction account for 18% of species, with forage accounting for 12%. The first two introduction pathways are most common for urban floras globally as well (La Sorte et. al 2014). Forage plants may be the remnant of former wide-spread agriculture in the area, or may be the result of contemporary seed mixes used to cover bare ground during construction.

Over half of the invasive plants in Indianapolis were known in the flora prior to 1940 (Fig. 6). Nineteen percent were documented by as early as the 1890s. Most invasives are herbaceous (n = 40) (Table 1). Shrubs are the most commonly represented woody class (n = 19), followed by trees (n = 6) and vines (n = 4) (Table 2, Fig. 7).

Herbaceous invasives have long been in the flora. As early as the late 1800s, Wilson (1895) noted Daucus carota and Glechoma hederacea were very common, Meliolotus officinale and Saponaria officinale were common, and Vinca minor was becoming common. Most herbaceous invasives (60%) were known for Indianapolis by Deamin 1940 (Table 1). Another 20% were noted by Deam (1940) for elsewhere in Indiana, so it would not be surprising if they were present in the city (or soon would be) but had not yet been recorded. Arriving since Deam's publication are Alliaria petiolata, Artemesia vulgaris, Centaurea stoebe, Clematis terniflora, Lespedeza cuneata, Microstegium vimineum, and Najas minor.

Analysis of the dates of record for woody plants reveals a different pattern. Only 14% (4 of 29) were known historically for Indianapolis (Table 2), with another eight present elsewhere in the state based on Deam (1940). As noted by Dolan et al. (2011), non-native shrubs escaped from landscaping are the physiognomic group with the largest increase in numbers of species in the Indianapolis flora over the last 70 years. Many of these plants were planted by the city as part of the Kessler Plan, a parkway and boulevard beautification plan during the 1920s (Table 2). Others were actively promoted by the USDA and other government agencies in the past for wildlife food and cover, erosion control, and other purported benefits (Tables 1 & 2).

Five of the seven species that were most frequently cited by restoration experts surveyed for this study as the biggest current invasive plant problems in Indianapolis are woody (Table 3). Euonymous fortunei and Lonicera maackii tied for first as the biggest current problem. Among plants that were perceived as emerging problems, three (one shrub, one grass and one tree) tied for first: Fallopia japonica, Microstegium vimineum, and Pyrus calleryana.

Early detection and rapid response protocols are the most effective means of preventing the spread of invasive species into new territories. It is widely recognized to be easier to eradicate and control invasive species before they become widely established (e.g., Allendorf & Lundquist 2003). Reports of new sightings posted to EDDMapS and other online sites by consultants, naturalists, academics, and the general public provide the opportunity to track new records and to eradicate plants before they can spread. Greater awareness of invasive plants and their modes or pathways of introduction will hopefully lead to more careful vetting and selection of plants for large-scale landscaping projects in the city and elsewhere.

ACKNOWLEDGMENTS

I want to thank Ellen Jacquart with the Indiana Field Office of The Nature Conservancy for encouraging me to present a paper on this topic for the Midwest Invasive Species Network Symposium, part of the North Central Weed Society Annual Conference in Indianapolis in 2015 and for her tireless work on invasive plant management for many years. A version of the data in this paper was also presented at the Annual Meeting of the Indiana Academy of Science in 2016. I also extend thanks to the restoration professionals in the city who provided anonymous responses to my survey on worst current and emerging invasives, and to the city of Indianapolis' Land Stewardship staff who are often the first to notice, collect, and report new invasive plants. Finally, thank you to Marcia Moore and Butler University undergraduate students for helping advance all Friesner Herbarium projects.

LITERATURE CITED

Allendorf, F.W. & L.L. Lundquist. 2003. Introduction: population biology, evolution, and control of invasive species. Conservation Biology 17:24-30.

Barr, R.C., B.E. Hall, J.A. Wilson, C. Souch, G. Lindsey, J.A. Bacone, R.K. Campbell & L.P. Tedesco. 2002. Documenting changes in the natural environment of Indianapolis-Marion County from European settlement to the present. Ecological Restoration 20:37-46.

Coulter, S. 1899. A catalog of the flowering plants and of the ferns and their allies indigenous to Indiana. Indiana Department of Geology and Natural Resources, Indianapolis, Indiana. 1073 pp.

Czarapata, E.J. 2005. Invasive Plants of the Upper Midwest: An Illustrated Guide to Their Identification and Control. University of Wisconsin Press, Madison, Wisconsin. 236 pp.

Deam, C.C. 1940. Flora of Indiana. Department of Conservation, Wm. B. Burford Printing Co., Indianapolis, Indiana. 1236 pp.

Dolan, R.W. & M.E. Moore. 2016. Indiana Plant Atlas. [S.M. Landry and K.N. Campbell (original application development), USF Water Institute. University of South Florida]. Butler University Friesner Herbarium, Indianapolis, Indiana. At: http://indiana.plantatlas.org (Accessed 20 November 2015).

Dolan, R.W., M.E. Moore & J.D. Stephens. 2011. Documenting effects of urbanization on flora using herbarium records. Journal of Ecology 99:1055-1063.

EDDMapS. 2016. Early Detection & Distribution Mapping System. At: https://www.eddmaps.org (Accessed 20 November 2015).

Homoya, M.A., D.B. Abrell, J.R. Aldrich & T.W. Post. 1985. Natural Regions of Indiana. Proceedings of the Indiana Academy of Science 94:245-268.

Indiana Invasive Species Council. 2016. Official Invasive Plant List. At: https://www.entm. purdue.edu/iisc (Accessed 15 November 2015).

La Sorte, F., M. Aronson, N. Williams, B. Clackson, L. Celesti-Grapow, S. Cilliers, R.W. Dolan, A. Hipp, S. Klotz, I. Kuhn, P. Pyuek, S. Siebert & M. Winter. 2014. Beta diversity of urban floras within and among European and non-European cities. Global Ecology and Biogeography 23:769-779.

Overlease, W.R. & E. Overlease. 2007. 100 Years of Change in the Distribution of Common Indiana Weeds. Purdue University Press, West Lafayette, Indiana. 248 pp.

Pimentel, D., R. Zuniga & D. Morrison. 2005. Update on the environmental and economic costs associated with alien-invasive species in the United States. Ecological Economics 52:273-288.

Pysek, P. 1998. Alien and native species in Central European urban floras: a quantitative comparison. Journal of Biogeography 25:155-163.

van Ham, C., P. Genovesi & R. Scalera. 2013. Invasive Alien Species: The Urban Dimension, Case Studies on Strengthening Local Action in Europe. International Union for the Conservation of Nature, Brussels, Belgium. 104 pp.

USDA, NISIC. 2016. The National Invasive Species Information Center. At: http://www. invasivespeciesinfo.gov (Accessed 2 July 2016).

Weber, E. 2003. Invasive Plant Species of the World: A Reference Guide to Environmental Weeds. University of Potsdam, Potsdam, Germany. 560 pp.

Wilson, G.W. 1895. Flora of Hamilton and Marion Counties, Indiana. Proceedings of the Indiana Academy of Science 4:156-175.

Manuscript received 22 July 2016, revised 31 August 2016.

Rebecca W. Dolan (1): Friesner Herbarium, Butler University, Indianapolis, IN 46208 USA

(1) Corresponding author: Rebecca W. Dolan, 317-940-9413 (phone), 317-940-9519 (fax), rdolan@butler.edu.

Caption: Figures 1-2.--Images of herbarium specimens. 1. Specimen of invasive plant Lythrum salicaria collected by Ray Friesner in Indianapolis in 1925, documenting presence of the species in the city as of that date (left). 2. Specimen of Berberis thunbergii collected by Charles Deam, with the comment on the label that this ornamental plant was collected far from any dwelling. Comments like these are helpful in establishing records for species that might become invasive (right).
Table 1.--Herbaceous species of invasive plants in the Indianapolis,
Indiana flora and time of first record. D = listed as present
elsewhere in Indiana by Deam (1940); P = planting actively promoted by
government agencies at some time.

Scientific name                     Common name         Pre-1940

Alliaria petiolata             garlic mustard
Artemesia vulgaris             mugwort
Carduus nutans (D)             musk thistle
Centaurea stoebe               spotted knapweed
Cirsium arvense                Canada thistle              x
Cirsium vulgare                bull thistle                x
Clematis terniflora            sweet autumn clematis
Conium maculatum (D)           poison hemlock
Convolvulus arvense            field bindweed              x
Coronilla varia (P)            crown vetch                 x
Cynanchum louiseae             black swallow-wort          x
Daucus carota                  Queen Anne's lace           x
Dioscorea polystachya (D)      Chinese yam
Dipsacus fullonum              common teasel               x
Dipsacus laciniatus            cut-leaved teasel           x
Euphorbia esula                leafy spurge                x
Glechoma hederacea             creeping Charlie            x
Hesperis matronalis            dame's rocket               x
Humulus japonicus (D)          Japanese hops
Hypericum perforatum           St. John's wort             x
Iris pseudoacorus (D)          yellow iris
Kummerowia stipulacea (D,P)    Korean lespedeza
Kummerowia striata (P)         striate lespedeza           x
Lespedeza cuneata (P)          sericea lespedeza
Lythrum salicaria              purple loosestrife          x
Melilotus officinale           sweet clover                x
Microstegium vimineum          Japanese stiltgrass
Myriophyllum spicatum (D)      Eurasian watermilfoil
Najas minor                    braided naiad
Pastinaca sativa               wild parsnip                x
Phalaris arundinacea (P)       reed canarygrass            x
Phragmites australis           common reed                 x
Potamogeton crispus            curly-leaved pondweed       x
Ranunculus ficaria             lesser celandine
Saponaria officinalis          bouncing bet                x
Schedonorus arundinaceus (P)   tall fescue                 x
Sorghum halepense              Johnson grass               x
Torilis japonica (D)           Japanese hedge parsley
Typha angustifolia             narrow-leaved cattail       x
Vicia cracca (P)               cow vetch                   x

                               More     Invasive
Scientific name                recent     rank          Origin

Alliaria petiolata               x      high       Europe
Artemesia vulgaris               x      high       Eurasia/N. Africa
Carduus nutans (D)               x      high       Europe/N. Africa
Centaurea stoebe                 x      high       Europe
Cirsium arvense                  x      high       Eurasia
Cirsium vulgare                  x      high       Europe
Clematis terniflora              x      caution    Asia
Conium maculatum (D)             x      high       Eurasia/N. Africa
Convolvulus arvense              x      high       Asia
Coronilla varia (P)              x      high       Eurasia/N. Africa
Cynanchum louiseae               x      high       Europe
Daucus carota                    x      medium     Eurasia
Dioscorea polystachya (D)        x      high       Asia
Dipsacus fullonum                x      high       Eurasia/N. Africa
Dipsacus laciniatus              x      high       Eurasia/N. Africa
Euphorbia esula                  x      high       Eurasia
Glechoma hederacea               x      medium     Europe
Hesperis matronalis              x      high       Eurasia
Humulus japonicus (D)            x      high       Asia
Hypericum perforatum             x      Low        Europe
Iris pseudoacorus (D)            x      high       Europe/Africa
Kummerowia stipulacea (D,P)      x      high       Asia
Kummerowia striata (P)           x      medium     Asia
Lespedeza cuneata (P)            x      high       Asia
Lythrum salicaria                x      high       Europe
Melilotus officinale             x      medium     Eurasia
Microstegium vimineum            x      high       Asia
Myriophyllum spicatum (D)        x      high       Europe/N. Africa
Najas minor                      x      high       Eurasia/N. Africa
Pastinaca sativa                 x      medium     Eurasia
Phalaris arundinacea (P)         x      high       Europe
Phragmites australis             x      high       Global
Potamogeton crispus              x      high       Europe
Ranunculus ficaria               x      caution    Europe
Saponaria officinalis            x      medium     Europe
Schedonorus arundinaceus (P)     x      medium     Europe
Sorghum halepense                x      high       Europe
Torilis japonica (D)             x      caution    Eurasia
Typha angustifolia               x      high       Eurasia
Vicia cracca (P)                 x      medium     Eurasia

Scientific name                     Use/mode of introduction

Alliaria petiolata             food, medicinal
Artemesia vulgaris             medicinal?
Carduus nutans (D)             none/unknown
Centaurea stoebe               none/unknown
Cirsium arvense                contaminated seed crop?
Cirsium vulgare                none/unknown
Clematis terniflora            ornamental
Conium maculatum (D)           none/unknown
Convolvulus arvense            ornamental
Coronilla varia (P)            erosion control
Cynanchum louiseae             ornamental
Daucus carota                  medicinal?
Dioscorea polystachya (D)      ornamental, food
Dipsacus fullonum              wool combing
Dipsacus laciniatus            wool combing
Euphorbia esula                accidental contaminant, ornamental
Glechoma hederacea             medicinal, food
Hesperis matronalis            ornamental
Humulus japonicus (D)          ornamental
Hypericum perforatum           medicinal
Iris pseudoacorus (D)          ornamental
Kummerowia stipulacea (D,P)    forage
Kummerowia striata (P)         forage
Lespedeza cuneata (P)          erosion control, forage
Lythrum salicaria              ornamental, medicinal, honey
Melilotus officinale           forage, honey
Microstegium vimineum          accidental, in packing material
Myriophyllum spicatum (D)      aquarium trade, boats
Najas minor                    ships' ballast, ornamental
Pastinaca sativa               ornamental
Phalaris arundinacea (P)       hay, forage
Phragmites australis           ships' ballast?
Potamogeton crispus            none/unknown
Ranunculus ficaria             ornamental
Saponaria officinalis          ornamental, soap
Schedonorus arundinaceus (P)   forage, erosion control
Sorghum halepense              forage
Torilis japonica (D)           none/unknown
Typha angustifolia             ornamental
Vicia cracca (P)               forage

Table 2.--Woody species of invasive plants in the Indianapolis,
Indiana flora and time of first record. Caution means there is reason
to believe the species may become a problem, but not enough data yet
to support its listing. D = reported by Deam (1940) for elsewhere in
Indiana; K = planted by the city in the 1920s as part of the Kessler
Plan; P = planting actively promoted by government agencies at some
time.

Scientific name                     Common name        Pre-1940

Trees
  Acer platanoides              Norway maple
  Ailanthus altissima           tree-of-heaven            x
  Alnus glutinosa (D,K,P)       black alder
  Morus alba (K)                white mulberry            x
  Pyrus calleryana              Callery pear
  Ulmus pumila                  Siberian elm
Woody vines
  Ampelopsis brevipedunculata   porcelain berry
  Celastrus orbiculatus         oriental bittersweet
  Hedera helix                  English ivy
  Lonicera japonica (D)         Japanese honeysuckle
Shrubs
Berberis thunbergii (K)      Japanese barberry         x
  Elaeagnus angustifolia (P)    Russian olive
  Elaeagnus umbellata (P)       autumn olive
  Euonymus alatus               burning bush
  Euonymus fortunei             winter-creeper
  Fallopia japonica             Japanese knotweed
  Frangula alnus (P?)           glossy buckthorn
  Ligustrum obtusifolium (D)    blunt leaved privet
  Ligustrum vulgare (D)         common privet
  Lonicera maackii              Amur honeysuckle
  Lonicera morrowii (K)         Morrow's honeysuckle
  Lonicera tatarica             Tatarian honeysuckle
  Lonicera 3 bella (K)          Bell's honeysuckle
  Rhamnus cathartica (D,K,P?)   common buckthorn
  Rhodotypos scandens           jetbead
  Rosa multiflora (D,K,P)       multiflora rose
  Rubus phoenicolasius (D)      wine raspberry
  Viburnum opulus var. opulus   highbush cranberry
  Vinca minor                   periwinkle                x

                                 More    Invasive
Scientific name                 recent     rank          Origin

Trees
  Acer platanoides                x      high       Eurasia
  Ailanthus altissima             x      high       Asia
  Alnus glutinosa (D,K,P)         x      high       Eurasia/N. Africa
  Morus alba (K)                  x      high       Asia
  Pyrus calleryana                x      high       Asia
  Ulmus pumila                    x      medium     Asia
Woody vines
  Ampelopsis brevipedunculata     x      caution    Asia
  Celastrus orbiculatus           x      high       Asia
  Hedera helix                    x      medium     Asia/N. Africa
  Lonicera japonica (D)           x      high       Asia
Shrubs
Berberis thunbergii (K)        x      high       Asia
  Elaeagnus angustifolia (P)      x      medium     Asia
  Elaeagnus umbellata (P)         x      high       Asia
  Euonymus alatus                 x      medium     Asia
  Euonymus fortunei               x      high       Asia
  Fallopia japonica               x      high       Asia
  Frangula alnus (P?)             x      high       Eurasia
  Ligustrum obtusifolium (D)      x      high       Eurasia
  Ligustrum vulgare (D)           x      medium     Eurasia
  Lonicera maackii                x      high       Eurasia
  Lonicera morrowii (K)           x      high       Eurasia
  Lonicera tatarica               x      high       Eurasia
  Lonicera 3 bella (K)            x      high       Eurasia
  Rhamnus cathartica (D,K,P?)     x      high       Eurasia
  Rhodotypos scandens             x      caution    Asia
  Rosa multiflora (D,K,P)         x      high       Asia
  Rubus phoenicolasius (D)        x      caution    Asia
  Viburnum opulus var. opulus     x      caution    Europe
  Vinca minor                     x      medium     Europe

Scientific name                 Use/mode of introduction

Trees
  Acer platanoides              ornamental
  Ailanthus altissima           ornamental
  Alnus glutinosa (D,K,P)       ornamental
  Morus alba (K)                ornamental, food,
                                  silk worms
  Pyrus calleryana              ornamental
  Ulmus pumila                  ornamental
Woody vines
  Ampelopsis brevipedunculata   ornamental
  Celastrus orbiculatus         ornamental
  Hedera helix                  ornamental
  Lonicera japonica (D)         ornamental
Shrubs
Berberis thunbergii (K)         ornamental
  Elaeagnus angustifolia (P)    erosion control,
                                  ornamental
  Elaeagnus umbellata (P)       ornamental, wildlife
                                  food & cover
  Euonymus alatus               ornamental
  Euonymus fortunei             ornamental
  Fallopia japonica             ornamental, erosion
                                  control
  Frangula alnus (P?)           ornamental
  Ligustrum obtusifolium (D)    ornamental
  Ligustrum vulgare (D)         ornamental
  Lonicera maackii              ornamental, wildlife food
                                  & cover, erosion control
  Lonicera morrowii (K)         ornamental
  Lonicera tatarica             ornamental
  Lonicera 3 bella (K)          ornamental
  Rhamnus cathartica (D,K,P?)   ornamental
  Rhodotypos scandens           ornamental
  Rosa multiflora (D,K,P)       ornamental, living fence,
                                  wildlife cover & food
  Rubus phoenicolasius (D)      ornamental
  Viburnum opulus var. opulus   ornamental
  Vinca minor                   ornamental

Table 3.--The top five ranked invasive plant species, including ties,
that pose the biggest current and emerging threats in Indianapolis,
Indiana, based on expert opinion. Rankings represent the frequency of
citation, with one (1) being the most frequently cited.

Current

Rank          Scientific name           Common name

1          Euonymus fortunei       purple winter-creeper
1          Lonicera maackii        Amur honeysuckle
3          Alliaria petiolata      garlic mustard
4          Celastrus obiculatus    oriental bittersweet
5          Euonymus alatus         burning-bush
5          Lonicera japonica       Japanese honeysuckle
5          Pyrus calleryana        Callery pear

Emerging

Rank          Scientific name           Common name

1          Fallopia japonica       Japanese knotweed
1          Microstegium            Japanese stiltgrass
           vimineum
1          Pyrus calleryana        Callery pear
4          Berberis thunbergii     Japanese barberry
5          Clematis terniflora     sweet autumn clematis
5          Euonymus alatus         burning bush

Figures 3-7.--Characteristics of invasive species in the
Indianapolis, Indiana flora. 3. Invasive rank based on the Official
Indiana Invasive Plant List (top left). 4. Continent of origin (top
right). 5. Mode of introduction (middle). 6. Time of first record
in the flora (bottom left). 7. Physiognomy (bottom right).

Use or Cause of Introduction

Accidental/unknown                 18%
Erosion, wildlife food/cover        6%
Food/Medicinal                      7%
Forage                             12%
Ornamental                         53%
Other                               4%

Note: Table made from pie chart.

Time First Documented

1890s    19%
1940     35%
later    46%

Note: Table made from pie chart.

Physiognomy

Herbs         58%
Trees          9%
Woody vines    6%
Shrubs        27%

Note: Table made from pie chart.
COPYRIGHT 2016 Indiana Academy of Science
No portion of this article can be reproduced without the express written permission from the copyright holder.
Copyright 2016 Gale, Cengage Learning. All rights reserved.

Article Details
Printer friendly Cite/link Email Feedback
Author:Dolan, Rebecca W.
Publication:Proceedings of the Indiana Academy of Science
Article Type:Report
Geographic Code:1USA
Date:Nov 22, 2016
Words:3659
Previous Article:Water quality assessment of Prairie Creek Reservoir tributaries in Delaware County, Indiana.
Next Article:Population ecology study of Epifagus Virginiana (L.) W.P.C. Barton (Beechdrops) in Central Indiana.
Topics:

Terms of use | Privacy policy | Copyright © 2020 Farlex, Inc. | Feedback | For webmasters