|Invasive plant species lists by state|
LINK TO LIST
An Act Concerning Fines For Banned Invasive Plants
Delaware's Invasive Plant List
Florida Exotic Pest Plant Council Invasive Plant Lists
List of Non-native Invasive Plants in Georgia
Invasive Plant Species in Illinois Forests
Indiana DNR Species Assessments
Division of Forestry
Invasive Plant Threats
Invasive Species of Concern
Massachusetts Prohibited Plant List
Plants Assessed through MPIAS
Minnesota invasive non-native terrestrial plants - an identification guide for resource manager
Conservation Commission Invasive Plants
Overview of Non-Indigenous Species in New Jersey
New York Invasive Species Clearinghouse
Invasive Plants of North Carolina
Invasive Plant Species of Ohio
Ontario's Most Unwanted Factsheet Series
Invasive Exotic Plants In Pennsylvania List
Rhode Island Invasive Species Council
Official List of Invasive Plants
Invasive Species Watch List
Invasive Alien Plant Species of Virginia
Invasive Plants In West Virginia
Invasive Species: Plants
Sunday, January 30, 2011
Tuesday, January 04, 2011
Today there is a chance to reign in its spread before it replaces major parts of the ecosystems of the Chesapeake Bay region. Dr. Marc Imlay and is band of weed warriors is seeking funding to quash the invasion before it becomes so big as to be unstoppable. The land managers know they can contain it and "weed" it out now; that they have a fighting chance to stop the spread, or at least to surely slow it down enough to mitigate and limit the ecological harm it may cause as it replaces the native species in the food web that occupy unique niches in the present ecosystem.. Doing something now costs far less than waiting to try to control it once everyone knows there is a problem. With invasive species, by the time the every one feels or sees the problem, the costs of control, containment or eradication exceed the resources available. The weed warriors seek 3 million dollars to eradicate the expansion and reduce the acreage under attack. Smaller amounts of funding mean smaller reductions of this pest, and a resulting limited reduction in effect control. Of course any reduction is better than none, but they know that they could get it all now even as they watch it spread to that point of no return while we dither and say perhaps there is no problem at all.
EDDMapS shows the current distribution. Marc Imlay, a relentless weed warrior, told me in 2006 [Nov 27, 2006 New Invasive; Early Detection; Rapid Response] that "Paul Peterson at the Natural History museum identified the grass as Oplismenus hirtellus subsp undulatifolius. He published a note on this grass in 1999 along with Charlie Davis, Ed Uebel and Rob Soreng, when it was found to be a new record for North America. Ed Uebel discovered it in Patapsco Valley State Park, (MD) and another site several miles north of the park, occurring in small to medium sized patches. It is native to southern Europe and southeastern Asia. It certainly sounds like it has the potential to be another invasive since it is stoloniferous, has seeds that stick to clothing, and appeared to be spreading according to Ed Uebel." I note that in that posting the nursery industry's variegated ornamental species was suspected as having mutated and escaped, a premise which since has been dismissed as information from genetic testing has confirmed a distinct difference.
(Talley & Ramsey, 2009)
The spread of this non native grass has reached the mountains and woodlands of the Shenandoah and shows no signs of slowing down. Folks say that this Oplismenus from Japan can "eat" Japanese stilt grass, (a major invasive species, Microstegium vimineum (Trin.) A. Camus), for breakfast and keep covering the forest bottoms in a dense carpet creating a biological desert. At first there was controversy as to whom to blame, and taxonomic lumpers and splitters trying to decide exactly "which of what" was invading. The apparent genetic plasticity found in the literature for the last two centuries of the species world wide is a likely indicator of potential invasive tendencies, but the recourse to absolute science has a tendency to hold up any action until the end of the play. So for a decade or so the species wandered taxonomically and ecologically in the wilderness of inattention. Searches through the scientific literature since the early 19th century suggested that the genus was remarkably prone to interspecific crosses. In other words this was a plant that could adapt easily and readily to the north side of a mountain as well as the south side and produce quickly seemingly different species based upon location and morphology. The point is that the genus can survive in a wide range of ecological conditions.
The genus Oplismenus is globally dispersed and has challenged categorization since its first mention by that great naturalist and botanist, Ambrose-Marie-François-Joseph Palisot de Beauvois, around 1810. An aristocrat who travelled to West Africa, caught in military actions between the French and British, forced to leave due to illness for Haiti; he continued his collecting with a strange aside into the politics of slavery. Once more finding his collections burned and this time forced to leave because of the revolution, unwilling as an aristocrat to return to revolutionary France, he set out for the United States. Destitute he arrived in Philadelphia, joined the circus as a musician and began "…curating the private botanical collection of Charles Willson Peale. He joined the American Philosophical Society, contributed to its Transactions, and resumed his collecting with the sponsorship of the French Attache, Paul Adet, a scientist in his own right. Palisot's collecting trips in the United States ranged from the Ohio River in the west to Savannah, Georgia in the south. He made several valuable discoveries, including that of a new species of rattlesnake, and he passed several months among the Creek and Cherokee Indians. He was elected a member of the American Philosophical Society, to which he communicated a part of his observations. Palisot finally received word from Paris that his citizenship had been restored, and began planning his return to Europe, especially the freighting of his collections. Dogged by misfortune, these collections were lost in a shipwreck off Nova Scotia in 1798. Palisot returned to France in the same year." 
To say that the taxonomy has been a little less than clear is to not do justice to the two centuries of expert discussion. Ursula Scholz describes the contortions of taxonomy clearly showing the pathway to the present epithet. She writes that "…historical consideration of the genus proves clearly how difficult the separation of the species from one another is. This was made especially evident through the very objective research methods of Davey & Clayton. From that one may doubtless conclude that through a classical systematic approach no fully satisfying results can be expected."  (Scholz, 1981)
As usual this problem can be boiled down and thus simplified to: who cares? For most people one grass is the same as another as long as it green. Few people are willing to pay more to clean weed a park; a place they see was "wild" already and suitable for weeds and other scary things. A few suggest that those who love wild natural areas should bear the financial burden of maintaining what they love so much. For them natural areas are a resource to be protect only when it is generating economic value directly to them individually. A natural resource that is not being exploited is simply wilderness waiting for human labor to turn it into something worth while. The dumping of our biological refuse onto unmanaged lands is not seen as a problem but rather one of the principle uses of untamed, unmanaged, undeveloped landscapes. If the land has not been shaped for a better use, why pay money to remove just another plant that someone does not like? And finally there is the group that believes that whatever problem may or maynot happen, we will deal with it when the time comes if the problem is big enough we shall overcome somehow, but in the meantime we have present problems of enormous cost that need dealing with on a more urgent basis than removing one somewhat aggressive species from the woods. So the question remains: Who cares? -our modern version of Cui bono?
 EDDMapS. 2011. Early Detection & Distribution Mapping System. The University of Georgia - Center for Invasive Species and Ecosystem Health. Available online at http://www.eddmaps.org/; last accessed January 4, 2011.
Palisot biography - Scarab Workers http://www-museum.unl.edu/research/entomology/workers/APalisot.htm
 Scholz, U. 1981. Monographie der gattung Oplismenus (Gramineae). Phanerogamarum monographiae Tomus XIII. J. Cramer, Vaduz, Germany. 217 pp. With 46 figures and 2 tables. Englush translation by Anthony McIntyre, Spencer Atkins, and Felix Tweraser. Published by A.R Gantner Kommandit community, FL-9490 VADUZ; © 1981 A.R. Gantner Verlag K.G., FL-9490 Vaduz; Printed in Germany by Strauss & Cramer GmbH, 6945 Hirschberg 2
"The genus Oplismenus was not always unanimously defined. Palisot de Beauvois (1810) identified seven species in addition to the type species O. africanus. Persoon (1805) had previously put these together as two species groups: “Spic. composita, spicul. compressis secundis” . Valid combination changes of these species that Persoon quotes from Panicum, are first found in Palisot de Beauvois, Essai d’une nouvelle Agrostographie: 53 (1812). They are as follows: O. bromoides, O. burmannii, O. compositus, O. elatior, O. helvolus and O. hirtellus. In addition, the species O. foliaceus and O. undulatiflolius were named. The designation of “foliaceus” is clearly due to a typographical error in which O. loliaceus is named a synonym, as only Panicum loliaceum Lam. appears in the index of the Agrostrograph.
The case of O. undulatiflolius is more complicated. In text S. 54 O. undulatifolius – like the other speciesl – is listed as nomen nudum. In the Index s. 168 “Panicum undulatifolium And (Ard.)” is listed as a synonym for O. burmannii, and “Panicum undulatifolium ? L.” is listed as a synonym of O. undulatifolius. As no Panicum undulatifolium exists this combination is invalid (Niles & Chase 1925; Becherer 1929).
The type species of the genus O. africanus was described, illustrated, and nameed as a separate species next to Panicum hirtellum L. and Panicum loliaceum Lam. by Palisot de Beauvois. No voucher specimen is cited. Two specimens can, however, be studied, as they were well known to Palisot de Beauvois and have comments on them: “types de la Flora d’ Oware et de benin” (G) and “dedit Palisot de Beauvois” (LE). Both plants are similar in their habit (very delicate), they are however, relatively strongly differentiated in their inflorescence characteristics. The specimen 1 from Geneva corresponds to the depiction in the Flore d’oware et de Benin and should therefore be considered the lectotype. The specimen 2 from Leningrad is intermediate between O. hirtellus subsp. fasciculatus and subsp. setarius.
Like Palisot de Beauvois, R. Brown also tightly circumscribed his genus Orthopogon (Greek origin: όρθός straight, πώγων beard) and only compiled species under it that have awns in the outer three glumes and whose spikelets are pressed together from the sides. He lists Orthopogon compositus (= Panicum compositum L.) and three further species that he described, Orthopogon aemulus , Orthopogon flaccidus and Orthopogon imbecillis.
The genus Oplismenus is described with similar circumscriptions by Roemer & Schultes (1817), Raddi (1823), Nees von Esenbeck (1829 and 1841) , Bentham & Hooker (1883), Domin (1915), Hitchcock (1913 on following pages), Koidzumi (1925) and Honda (1924 and 1930). In contrast to this circumscription, which we consider to be Oplismenus s. str., are the interpretations of Kunth in Humbolt, Bonpland & Kunth (1816) and Kunth (1833), Desvaux (1831 and E. Fournier (1816) who sxpanded the genus to include the genus now known as Echinochloa as a section of Oplismenus. Even so Sprengel (1825) also recognized Orthopogon. Later however, like the earlier Poiret (1816) and after him Steudel (1854), Sprengel reduced Orthopogon to a section of Panicum, while Trinius, in earlier works (1820) accepted Orthopogon s. str. Mez (1917 and 1921) accepted Oplismenus (s. str.), but added to it some species that belong in different genera.
Schechtendal (1961-62) divided Oplismenus into two sections, base on characterisics of the awns. Species Oplismenus sect. Orthopogon (= sect. Oplismenus) have strong, red-gold, smooth awns, whereas members of Oplismenus sect. Scabrista have delicate, whitish, scabrous awns. This division appears sensible as the make-up of the awns is an important criterion, both in physiological as well as in dispersal.
Davey & Clayton (1977), in their study of some of the species of the genus, adopted new interpretations. They analyzed the species O. compositus, O. hirtellus, O. undulatifolius O. aemulus , O. imbecillis, O. rariflorus and O. setarius according using discriminate analysis (Cooley & Lohnes 1971). They compared all the species and attempted to separate them. They concluded that some species are easy to separate when one considers them within individual geographical regions, such as America, Africa, Asia, and Australia. When comparisons included specimens from multiple regions, however, they found some species to be non-separable species, O. hirtellus, O. compositus and O. undulatifolius. They concluded that there were no distinct boundaries between these three species”
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Monday, January 03, 2011
I want to thank Anekeia for taking the time to point out these metaphoric challenges. I am delighted to answer. I look forward to more comments and hope you have something to say:
Anekeia has left a new comment on your post "Invasive species are all around us":
"An interesting perspective, more thoughtful than many. But the metaphor seems mixed. Do hitchhikers invade?"
The word invasion comes from two words in Latin: IN meaning into and the verb VADO VADERE INVASI INVASUM meaning to go and in the past with past forms - to go into, Hence invade is simply the action of going in (without invitation I suppose). In English the word comes with a pejorative sense related to military, cultural or economic actions that have a negative consequence for the receiver of the invasion.
" Do plants and animals hitchhike?"
Yes the metaphor could be tightened; yes hitchhiking strictly speaking based upon current usage has a sense of intent. Better might be the insertion of "accidental or unintentional hitchhiker".
" Either action seems to require some kind of intention, and a sense that there is somewhere to be besides here. It must be a more desirable place for a hitchhiker to want to visit or inhabit. It must be a place worth the risk of conquering by an invader. If awareness or intention are lacking, they are abductees or castaways rather than hitchhikers or invaders. And what invader invades by reproducing? "
Here is where the analogies may have failed for I anthropomorphized the actions of non human species, I gave them human perspectives, intentions and agency in my choice of words. Anekeia correctly notes that invasion is a human activity in its basic sense though metaphoric use should let me use it with inanimate object such as the solar system was invaded by a new comet or the sterile operating room was invaded with dust particles. On the other hand hitchhiking at the root is a human activity and therefore my metaphor at best seems to have been a poor attempt at rhetorical, poetical liberty.
Strictly speak, geophysical processes such as water currents and wind, As well as other organisms, may provide a platform or vector that serves as a pathway for the transportation of the non indigenous from one ecological system to the next. In our current use of the term invasive species, we carefully define the method of movement as one due to human agency. Therefore non indigenous species are transported by human activities including the platforms and vectors of trade and commerce as well as simple human movement from one ecosystem to another. For a species to be invasive there is no need for intent as accidental introductions are possible and common.
Anekeia has correctly identified a key problem in the definition(s) of invasive species. The use of the word invasive itself is loaded with centuries of contextual meaning that colors the conversation before it starts. As a note even the word species has problems, but that is another post.
Sunday, January 02, 2011
Invasive species are all around us; they are ubiquitous. Invasive species as defined by Executive Order 13112 as a species "… that is non-native to the ecosystem under consideration and whose introduction causes or is likely to cause economic or environmental harm or harm to human health." Invasive species do not just happen, however; they are helped by human activities. Among these activities are human developmental disturbances, the chronic 'plowing' of natural areas, and the now global nature of the market place. The regular year after year pressures of human activity on the balance of existing ecological systems undermines the resiliency of the ecosystems and ultimately earth's biome. This is understandable as we extract resources from natural systems in order to develop our anthropic ecosystems to support human well-being. Moreover the pathways that our goods travel provide platforms for other species to hitch a ride from ecosystem to ecosystem throughout the world and across the planet.
An invasive species needs several things to happen in order for it to become established within a new ecological system. Among these is a pathway or a mechanism by which it can be transported from one ecosystem to another. And it needs this platform or vector to provide the pathway over time, that is more than once, so that multiple introductions can take place. For the most part, one introduction does not create an invasion event, though the gypsy moth introduction serves as a reminder that it is possible to do great harm through one well-meaning action. The very act of multiple introductions is a disturbance regime in the ecosystem that begins to alter the impacted ecological system. In addition the multiple introductions make it possible to overcome random events that might prevent its establishment.
The above mentioned random events are part of the resiliency of a complex system. An introduced seed may land on a rock and not germinate or in water where it drowns. An insect may be devoured by a bird or run into a windshield before it can lay its eggs or find a mate in order to reproduce. The initial invader may be stepped on or washed away before it can set down roots or start a family. And if it is the lone invader, it may never find that all important significant other. Multiple introductions of novel species increase the odds that two ecosystem immigrants may find each other and begin the process of establishment and eventual naturalization.
Examples of multiple introductions of plant species are easy to find and include kudzu, (Pueraria montana var. lobata), buffelgrass (Pennisetum ciliare), silver carp (Hypophthalmichthys molitrix), callery pears (Pyrus calleryana). Harder to demonstrate but almost certainly the result of many introductions over time are insects such as the emerald ash borer (Agrilus planipennis) or the brown marmorated stink bug, (Halyomorpha halys). The Asian lady bug (Harmonia axyridis) was repeatedly introduced as a biological control agent. Kudzu was intentionally planted for erosion control and as a forage crop in great numbers in the 1930s while the silver carp was stocked for recreational fishing. It is important to notice that not every invasive species was intentionally introduced. Many if not most were the result of accidental introduction or simply unnoticed hitchhiking.
For those who value the gardens, which they call natural areas, the constant influx of disease, insects, weeds and destructive animals from different ecosystems, leave no choice but to weed out the undesirable everyday, and to restrict the importation or movement of non indigenous possibly harmful species that may reduce or alter the 'garden' (natural area). This is what a farmer does everyday. He does not say that is alright to do nothing about the invasion of his 'garden" or fields. Rather he fences out the unwanted, weeds out the harmful plants, and fights the insects and diseases each and every day. The farmer may ask the government to protect the lands and his work from invasion from illegal alien species that have been shown to reduce his harvests. The farmer, moreover, is not alone. The ornamental landscape gardener does the same thing. Both decide which species should stay and which should not be allowed. The natural area manager does the same triage simply dealing with a larger palette of species and a corresponding greater complexity of interactions and relationships.
Invasive species have travelled with mankind ever since it first it settled down to a life style based upon farming. And in farming humanity undertook to plow the land and to tame nature which is to say to disturb the landscape annually. In doing so, mankind's actions favored certain species that were predisposed to find advantage in the constant disturbance of the environment. As agriculture allowed for the establishment of cities and dense populations of people, so it allowed for companion species to coevolve with the farm based cultures of man. And as man spread across the globe so these companion species came with him. The historic companions we call pests and weeds; the new companion species that are taking advantage of human disturbance and trade are called invasive species.
Saturday, January 01, 2011
Invasive species are changing your world. They are changing the landscapes right in front of your eyes, and they are literally eating your lunch. They are replacing species that you once took for granted like chestnut and elm and now ash trees, as well as changing the very texture of plants that support your world perhaps even your quality of life. And though they are doing this rather quickly, you are mostly oblivious because you can no longer read the landscape. If the grass is green and there are trees then all is well as you rush from crisis to crisis. You have become landscape illiterate because your immediate needs do not seem to correlate with the complex interactions and relationships among microbes, plants, insets, reptiles and animals and you.
Some invasive species are so personal you do, however, take notice and great amounts of time and energy, using early detection and rapid response strategies (EDRR) to keep pathogens, diseases and parasites out of that complex biological system known to you as your body. In this you are clear: that the ideal is to prevent the disease in the first place. And to this end you create quarantines, inspections and protocols that can stop commerce in its tracks. You are very careful not to let other people's uncontrolled adventures to exotic lands and places potentially impact your biological system. You are very willing to make a second party who provides a pathway for a disease pay the cost of prevention if possible. You hold the government accountable to the personal common good and expect it to inspect and detain travelers and merchandize that risk analysis have identified as probable vectors of human illness. Yellow fever, cholera, malaria, typhoid and influenza are in an analogous sense invasive species that once introduced into your biological system are able to wreak havoc.
We are more focused when business interests might be impacted by alien exotic agents of lower profits. Agriculture is very concerned about invasive disease, plants and animals that reduce harvests and yields, and therefore, make production costs higher than sales potential. In other words, pests like Russian wheat aphids or the European corn borer reduce the amount of grain produced per field acre, and drive up the costs of doing business and eventually the cost of food. Agriculture has recognized in the United States the idea of preemption as an effective approach to reducing invasive species impacts on production and therefore costs and profits since at least 1726 and the banning of barberry in Connecticut. There are even laws and regulation in place to protect ornamental landscapes and its nursery industry promulgated by USDA APHIS in partnership with the individual states (National Plant Board).
When it comes to your natural areas that preserve complex and diverse systems of life with as little human impact as possible, the rules change dramatically and the problems multiply as you externalize your life on to the dumping grounds of nature. A small group of advocates struggles to create a national policy with little to success. There is a national executive council (NISC) with an advisory committee (ISAC) but there is no funding; it can meet, network and advise, but it cannot make anything actually happen. Members and staff mostly talk to each other and to those very few who see the loss in the changes brought by invasive species. The landscape illiteracy translates in to an ignorance of the dynamics of ecological systems; systems to which you are an integral part. That green expanse in the parks of the mid-Atlantic is not a harmless flow of native grasses inviting to interacting with the ebb and flow of natural processes, but rather a non indigenous species which in my unsubstantiated lay opinion may have been introduced in utility rights-of-way seed mitigation mixes, is wavyleaf basket grass, Oplismenus hirtellus ssp. undulatifolius. This grass is spreading, as shown on EDDMapS, like a wild fire changing the fundamental make-up and processes of the last historic native species aggregations of the mid-Atlantic. As it crowds out native plants and the glorious wild flowers that provide sustenance to native insects, it is reducing the complexity of the food web and reducing the resiliency of these last great places of natural beauty and doing so without you seeing anything amiss. Desperate pleas from experts seeking funding in these economic times go unheeded; even in the heyday of uncontrolled spending bothering to spend money on the early eradication of a non native invader was never fully supported by you. You preferred to wait until the invader clearly and irrevocably damaged your personal space before you were willing to push your government to action.
A dead ash tree falling onto your house (Emerald ash borer epidemic threatens Ohio trees) because of a borer from Asia which you chose to ignore has caught your attention even as the lack of funding went mostly unnoticed, until millions of acres of ash trees began to die. Now it is a rear guard action trying to hold the line. Historically the gypsy moth showed us this scenario over 100 years ago (The Great Gypsy Moth War: The History of the First Campaign in Massachusetts to Eradicate the Gypsy Moth, 1890–1901), when you decided to un-fund early attempts at control only to watch your woodlands become defoliated by the introduced exotic pest. You have clearly said through your silence that you prefer to throw your unwanted pets out onto the street creating a feral cat assault on song birds and you waited until the 15 foot snakes from Burma entered your bedrooms before you said there might be something wrong.
You should have a national policy discussion; you need a plan and a fund much like the one you already have for wildfires that can be applied to early detection of invasive species and most importantly money for their rapid eradication at the time of detection when the costs are very small. You need to say that your natural areas are worth saving per se; that your management of these native enclaves will include the removal of certain species, and the preemption of their introduction into these United States.
I continue to propose the creation of an all taxa grassroots funded effort to advocate and educate members of Congress as to the impacts of invasive species.
Picture of dead trees from Natural Resources Canada
Picture of wavyleaf basket grass from forestry images.org