Welcome to the wonderful world of weedy plants!
Weeds are superevolutionary products of human civilizations and activities - without humans there would be no weeds, just wild plants.

Tuesday, June 30, 2015

Life Versus Death

Daucus carota, also known as wild carrot, bird’s nest, bishop’s lace, and Queen Anne’s lace, is a flowering plant native to Europe and southwest Asia, and naturalized to North America and Australia. While the carrots that we eat are domesticated versions of this species, Queen Anne’s lace bears an almost indistinguishable resemblance to a highly deadly plant, the poison hemlock. What’s worse, they’re often found in similar environments: dry meadows, roadsides, hiking trails, ditches, and deserted uncultivated waste areas. Poison hemlock and Queen Anne’s lace belong to the same family: Apiaceae or Umbelliferae, along with dill and parsley.

poison hemlock

Queen Anne's lace

The similarity in their appearances has led to some accidental poisonings (as Queen Anne's lace is used in all sorts of foods), and so being able to identify them and avoid accidental ingestion is very important. Queen Anne’s lace is distinguished by fine hairs on its solid green stem and on its leaves, a root that smells like carrots, and occasionally a single dark red or purple flower in the center of the umbel (inflorescence which consists of a number of short flower stalks which spread from a common point like umbrella ribs).  

Friday, April 24, 2015

Tomorrow, April 25 - War of the Weeds at Rutgers Day!

Come and visit our booth with educational activities on weeds!  Eat food made from weedy plants (wild onion cream cheese crackers, dandelion ice tea and rose hip smoothies), check your weedy plant species knowledge in our new card matching game, and check out the defense and attack systems of these superevolutionary and amazing plants. 

Our table is located between Food Science and the Cook/Douglass Lecture Hall, along the road and we are open 10 AM to 3 PM tomorrow.  It is right next to the giant booksale, which is worth a visit too!

New fieldguides are out!

Two updates fieldguides are just published and can be downloaded for printing - at no cost!

Field Guide to Weedy Plants of Eastern US

Weedy Grasses and Grasslike Plants of Eastern US

Print the first guide at 100% on LEGAL paper, double-sided, then fold in 4 parts.

Print the Grass guide on LETTER paper, double-sided and fold in 3 parts.

Wednesday, January 14, 2015

Mona Caron's "WEEDS": An alternative botanical animation

As the domain name states, "this is colossal"!...

Watch over-sized weedy paintings grow up on familiar urban structures: http://www.thisiscolossal.com/2014/12/mona-carons-murals-of-weeds-slowly-overtake-walls-buildings/

The take-away: "Sow alternatives- let resistance grow."

Friday, December 26, 2014

Weedy plant teas and infusions: Evaluated by freshman seminar students!

Our fall 2014 freshman seminar class on weedy plants taste-tested a variety of commercially-available herbal teas blends either composed partly or entirely of weedy species.

Here are the average ratings (1 [yuck!] to 4 [wow!]) and some anonymous comments on these wild infusions:

Rose Hip
Average Score: 2 out of 4
"Very herbal, strong after-taste, somewhat dry,... Reminds me of oatmeal, for whatever reason..."

Honeysuckle Herbal
Average Score: 3 out of 4
"Sweet, mild,... Don't let the fish-food look scare you! It is pretty good."
"Sweet, dark, fragrant,... My fish would like to try this."

Prickly Pear Cactus
Average Score: 3 out of 4
"Mild... Makes me interested to see what the cactus itself tastes like..."
"Mildly fruity... Luckily not prickly!"

Average Score: 3.5 out of 4
"Sweet, fragrant,... Can't go wrong with chamomile."
"Tastes herbal... I don't know how else to describe it."

Burdock Root
Average Score: 3.5 out of 4
"Very deep, roasty, smooth, soothing,... Using 2 teabags in a single cup may have added to the depth."
"Smells wonderful... Taste is milder,  but still good!"

"Fredagsmys" (a Swedish green tea blend with carrot, strawberry, sunflower, and cornflower)
Average Score: 4 out of 4
"Tastes like green tea... I like green tea."

Wednesday, November 19, 2014

Tweet, tweet, tweed, weed...

We asked our students to come up with come good tweets about what they learned in our Byrne 2014 seminar about weeds, and here is the result!
I've learned that weeds and flowers are no different biologically. 

Weeds are awesome.

Weeds are like onions. Onions have layers. Weeds have layers. They both hve lauers. #weedstho

I definitely have a new appreciation for weeds. Except for that unidentifiable grass. #Istillhavenoideawhatthatwas

Hated for the wrong reasons #weeds

Weeds, the hipsters of the plant world. People don't understand them and want them gone. They're still pretty cool though. 

Nothing about kush. Everything about dandelions #notthatkindofweed

I ate things that I probably stepped on earlier, and liked it! #dandelionicecream #weedsarecool

Weeds are not bad because they taste great on pizza and in every other type of food also it is natural and healthy #weedsforlife #weedsarecool

Thanks students for a great class!

Kudzu Has Outsmarted Us

Guest post by Patricia Chan, a freshman in 2014 Byrne seminar on weedy plants

Let me tell you about Pueraria montana var. lobata —it is a crazy, crazy, invasive weed.  This plant, commonly known as Kudzu, but also known as Japanese arrowroot, is a plant in the pea family, Fabacaeae.  You may be thinking: “it’s related to the pea, I guess it probably climbs” (ok you probably didn’t think that, but bear with me).  Well if you were thinking that, you are more than right.  Kudzu is an aggressive and skillful climber, much to the dismay of property owners of the southern United States. But before I tell you about this insane plant, let’s discuss how to recognize it in the wild.

File:Kudzu field horz1.JPG

CC Gsmith 

If you happen to stroll around anywhere in the southeast US and encounter a large green mass where there probably shouldn’t be one  - Congratulations!  You have found Kudzu. Kudzu is a very distinguishable plant from afar due to its tendency to cover large areas.   Up close, it may be slightly harder to recognize.  It’s got compound trifoliate leaves (meaning it has three leaflets on one stem) with a varying number of lobes on each leaflet from 1-3 lobes.  The leaves are fuzzy by the way, like a rabbit.  Like a very small, green, coarse, leaf-shaped rabbit…  The long vines cling to surfaces with little brown bristles that it uses to grapple over trees and buildings.  The flowers are a lovely deep pinkish purple hue and grow in clusters.  That’s nice.

photo by Peggy Greb, public domain 

Anyway, now that you know how to point out Kudzu when you see it, let’s learn more about how it behaves.  Kudzu has a very aggressive growing habit; in the right conditions, it can grow up to one foot per vine a day.  Monstrous.  People have reported losing entire cars to masses of Kudzu because they were parked for a few days.  How crazy is that?  In nature, Kudzu is considered a nuisance because it can envelop entire trees in short periods of time, killing forests by crowding out the light.  What a horrible plant to bring places, one may assume.

With that in mind, how did Kudzu even get here, not being native to this continent?  Maybe by a shipping mistake or a tourist?   No, in fact, Kudzu was brought to this country intentionally from Asia for ornamental and erosion prevention purposes.  That’s right, us humans spread this plant ourselves.  The sad truth is that we didn’t do the research we should have to ensure that this plant didn’t damage our ecosystems the way it did.  We just brought it over on a hypothesis and a whim.

This just goes to show: it’s wise not to mess with the natural order of things.  Not to say that it’s impossible to introduce a foreign species successfully, but a lot of heavy research must be done before it happens to make sure a monster isn’t unleashed.  All in all, Kudzu isn’t actually a wholly evil plant.  It carries medicinal purposes, has beautiful flowers, and it really does prevent erosion.  And in the end, it only behaves the way it because these characteristics have helped it to survive and reproduce in the past.  Kudzu acts to survive, and it just so happens that it is really good at doing that in the US.  What we need to do, however, is be more careful to monitor this kind of thing when considering what exotic plants to put where.  We need to be smart in our ecological decisions.

Weeds: The Public Census

Guest post by Tina Thawani, a student in the 2014 Byrne seminar on weedy plants

            A couple weeks ago I had to “Combat Plant Blindness” by showing someone a weed, identifying it, and telling them a bit about weeds in general.  I ran down a hill on Livingston campus and tugged on a plant that looked a bit like Queen Anne’s Lace.  I brought it back to my friend Rachel who was staring at me as if I was crazy, and explained that it was considered a weed.  She took one look at it and exclaimed, “Really? I didn’t know weeds could be so pretty.”  I then went on to explain to her the basis of the seminar: weeds, and the false image society has of them.
            Intrigued, the next day I decided to ask my roommate and a couple other people in my hall how they felt about weeds, as a miniature survey.  After hearing their initial reaction, I explained to them the real story behind weeds, then asked them again.
            I first asked Nikki, an accounting major from across the hall.   “So what do you know about weedy plants?”
            Nikki stifled a groan.  “Ugh, they’re so annoying.  I have to weed them out myself at our garden at home and it’s a lot of work to manage. Why?”
            “Well,” I started, “The term weeds is actually a subjective term, characterized almost exclusively by the fact that we humans don’t want that plant in our lawns and fields of view.  They tend to grow in abundance, and since they grow in places they weren’t planted, it’s actually an indication that they are evolutionarily more fit for the environment they occupy.  Many plants we call weeds, in other countries are considered useful and are even appreciated; for example, a weed called chicory can be used as a coffee substitute, and it is in many countries.  A weed called Queen Anne’s Lace is actually in the same species as carrots.  A weed called fennel can make nice after-meal mints, and mulberry, a woody weed, can be used to make paper and medicinal tea.  Sometimes, plants aren’t invasive, which means that they spread everywhere quickly, in their native countries, but when they’re brought to a different country through human interference, they react differently with the climate and habitat. Basically, most weeds happen solely because of us.” 
            “That’s cool,” Nikki said, nodding.  “That kinda opened up my definition of what weeds were, I never really saw it like that… but it doesn’t change the fact that I have to go through all this work.  I wish more people cared less about their gardens being perfect so that we could fully understand the role and possible benefits of weeds in our garden.  If the weeds weren’t so invasive, though, I don’t think they’d be so bad.”

            Next, I asked my roommate, Sarah, a biology major.  “What do you think of weeds?”           “Umm… weeds…they always get in the way of gardening and outdoorsy stuff like that right?” she said.  After giving him the same spiel I gave Nikki, her viewpoint had changed.
            “You’re right! They’re evolutionarily better, and I believe in evolution.  They’re annoying, but hey, they’re plants, and they have the same right as other plants.”

Lastly, I asked a guy who was playing pool with his friend in the first floor lounge.  “What do you think of weedy plants?” I asked. 
            “I think it should be legalized.  It’s better for the economy.” he said, as he twirled his pool stick. 
            “No, I mean, the other type.  Not marijuana,” I said with a sigh. 
            “Oh! Oh. Those.  Sorry. Uh… weeds… well, they’re stupid and annoying.  My dad has someone come in and weed the garden every month or so, cuz they grow so fast!”
            After he heard my speech, I asked him again - “So, what do you think of weeds now?”
            “Wow, I didn’t even know there was more than one type of weed.  Wait, so if they’re useful and diverse, why do we insist on planting our own flowers and removing the one that can grow there easily?  Ugh, Americans.”

            One thing I’ve confirmed from this experiment is that nobody really initially has a positive view, or even a neutral view, on weeds.  Yet, once they learn more about them, people are more sympathetic towards them.  I believe if people took my seminar on weeds, they too, would have a completely different viewpoint on weeds than they did before.  Like in most aspects of life, education is the cure-all.          

Thursday, November 13, 2014

How Weeds Become Weedy

Guest post by Patricia Chan, an undergraduate freshman in 2014 Byrne seminar on weedy plants
What is a weed?  Generally, it’s an incredibly hardy and pervasive plant that we as humans deem undesirable for our purposes.  Whether it’s a thorny bush in our yard, a vine stealing sun from our crops, or the wildflowers in our lawns that “ruin” the uniformity of our grass—weeds are what we make of them.

How to tell if that plant is a weed:
·         People don’t like it
·         It’s hard to get rid of

Honestly, I could talk all day about how we define plants as “bad”, “harmful”, and “ugly”, but enough about that.  Let’s discuss the second aspect that makes a plant a weed: their ability to survive, reproduce, and even flourish in the most trying conditions.  If you look at it this way, weeds are pretty incredible.  They manage to succeed in environments that limit all others and they seem pretty happy doing so too. 

In terms of ultimate hardiness and survival, weeds are the all-out winners.    They have and they continue to outwit other plants and animals every day, everywhere.

There are hundreds of adaptations that weeds evolve to outcompete other plants and evade humans, but my favorite adaptations are their aggressive defenses.  The parts of a weed that shout “I AM PREPARED” in the face of adversity.

Some plants produce oils that target and irritate animals trying to disrupt them- a commonly known one being poison ivy. 

Some plants produce thorns- that’s normal.  But then some plants produce serious don’t-you-even-think-of-touching-me-thorns.   That’s the case in the honey locust.  While its thorn-less variety is commonly grown around urban areas, its natural state is feared and frowned upon by most.  It has thorns covering the entire tree, with thorns growing off of thorns growing off of thorns.  No human or animal would ever want to mess with that tree.

cc Greg Hume
above: honey locust thorns growing straight off the thorns growing off of the trunk

Some plants, like the black walnut, go so far as to emit chemicals from their roots that kill plants around them and prevent others from growing.  Because of this, the black walnut tree can enjoy its nutrients and sunlight uninterrupted by close competition.  It is also because of this that the tree is considered a horrid weed by gardeners and farmers alike.

Acacia trees are yet another weedy and plentiful species with clever survival strategies.  In addition to their thorny defenses, they use chemicals to communicate with each other when threatened .  They are responsible for confusing countless scientists were studying unexplained antelope die-offs seemingly.  It turns out that when the antelope munched on the acacia leaves, the tree signaled to itself (and others) to begin producing toxins to reduce the threat. That’s impressive.

Any way you put it, weeds are an amazing achievement.  Most of us gardeners, farmers, homeowners, or bystanders may not appreciate weeds on a surface level, but let’s now recognize all the work in evolution that led them to where they are now.  Sure, invasive, mass spreading weeds may not always be conventionally beautiful, but there’s a reason why they’re hard to get rid of: we selected them to be that way. 

Next time you see that weed that seems to always come back, take a moment to applaud it as an impressive feat of nature, because that’s what weeds really are: they’re tough. 

Tuesday, October 21, 2014

Positive Poison

(Written by undergraduate student guest blogger from Byrne seminar Fall 2014 at Rutgers)

Ask any Boy Scout, backpacker, hiker, or avid outdoorsman what plant they’re most wary of, and the majority will give you the same answer: poison ivy.  Toxicodendron radicans, more commonly known as poison ivy, is a flowering plant found in North America and Asia.  It is well known for the itching, irritating, and occasionally painful rash contact causes in most people.  This reaction is caused by urushiol, a clear liquid in the sap of the plant, which, contrary to popular belief, serves not as a defense mechanism but as a way to help the plant retain water.  Because of the reaction it causes, poison ivy has gained a rather negative reputation in the eyes of most people.  Various mnemonic devices, such as “leaflets three, let it be”, have been coined to help in identifying and avoiding it. There’s even a super villain from the Batman comics named after it. 
 copyright: Larry Korhnak (http://www.sfrc.ufl.edu/extension/4h/plants/Poison_ivy/)
      Despite its negative effects on humans, poison ivy serves an important and beneficial role in the environment.  The poison ivy plant produces whitish, waxy berries that develop in the summer and persist into the winter, providing a food source for a variety of wildlife, including deer, squirrels, insects, and more than 60 species of birds.  Poison ivy is also very valuable to shoreline and coastal areas where, due to its salt tolerance and ability to grow in nutrient-poor soils, it plays an important role in preventing erosion and protecting sand dunes.  Several species of moths also use poison ivy plants to shelter their larvae while they pupate.
     So while poison ivy is considered a weed by most, it does have a positive side as well.  It just goes to show that even the most harmful and unwanted weeds can have their pluses. 

Monday, September 1, 2014

What will the plants of the future cities look like?

Well, very likely a lot of weeds.  Plants that we do not care much for today, plants that we think are ugly, useless, and unworthy, but that are persistent, drought-tolerant, and very good at surviving in harsh environments (and good ones too!).

Peter del Tredici has written an thought-provoking and great essay on The Flora of the Future: Celebrating the Botanical Diversity of Cities on the website the Design Observer. It is well worth a long, good read, especially if you live in an urbanized area or are interested in ecology and evolution. 

He starts off with a dramatic statement:

"The concept of ecological restoration, as developed over the past 20 years, rests on the mistaken assumption that we can somehow bring back past ecosystems by removing invasive species and replanting native species. This overly simplistic view of the world ignores two basic tenets of modern ecology — that environmental stability is an illusion, and that an unpredictable future belongs to the best adapted." (source link)
In short, nothing stays the same, and especially not now when we have changed the world so much when it comes to species distributions, human-built environments, and changing climates.

Read on... it is spot on and explains what is happening to plants in cities, industrial areas, and abandoned lots...

Friday, August 29, 2014

The "Parking Lot Project": Our Weedy Research Featured in the University Newsroom, 8/20/2014

Our weedy work has MADE it, big time! (Well, sort of...)

As you may or may not know, the creators of this blog form the Struwe research lab (http://www.rci.rutgers.edu/~struwe/at Rutgers University in New Brunswick, NJ, USA. This summer, the Rutgers School of Environmental and Biological Sciences (SEBS) Office of Communication wrote an online news article about one of our campus-based, wild urban plant (aka "weeds"!) biodiversity projects.

Dr. Struwe began this particular project in 2011 after noticing that weedy plant species were abundant right outside of our offices and labs here on Rutgers campus, and especially in the parking lot cracks and curb edges. For the past 3 years, plant surveys of campus parking lots have taken place on a yearly basis. I took the project under my wing this summer by expanding the sampling protocol from previous years and, most importantly, by giving this graduate research endeavor a nickname: the "Parking Lot Project", or "PLP", for short.

This summer was an interesting and exciting time for us in the lab because we had an undergraduate researcher (funded by Rutgers' Aresty Program) to help us with the field work and to develop a sub-project related to urban weeds of her own. Read the article, featuring Dr. Struwe, my undergraduate researcher assistant Alisha, and myself, here.

To all our of amazement, PLP 2014 will have identified over 100 plant species that grow and thrive in the extremely harsh conditions of Rutgers University-New Brunswick campus parking lots once the surveys are completed (and all samples identified!) this fall. Now I call that success!

Friday, April 25, 2014

Eat Your Weeds @ Rutgers Day: How to Safely Savor Wild Edible Plants

Tomorrow, April 26, 2014 is Rutgers Day in New Brunswick, New Jersey! Every year about 70,000 people come to Rutgers, The State University of New Jersey's New Brunswick campus for a huge festival celebrating all that is our university.

The Struwe lab (i.e. the writers and creators of this blog) will host a public outreach and education table entitled "Eat Your Weeds!: How to Safely Savor Wild Edible Plants." We will provide information about weedy plants, advice on urban foraging, and free samples of some original recipes that incorporate weedy plants to everyone who stops by. It will be a lovely way to celebrate the start of the growing season - and the upcoming end of the semester - here on campus!

Here is some information about my current favorite weedy plant and a recipe for a snack that we'll be serving tomorrow, garlic mustard hummus:
Delicious garlic mustard hummus on cracker (with a hairy cress leaf on top). Photo L. Struwe (cc).
Information about garlic mustard, Alliaria petiolata (Brassicaceae), an invasive species.
Recipe for garlic mustard hummus, developed by Sara Morris-Marano.

You can download our recipe handouts at this link, or under Download in the right navigation bar on this blog. 

Thursday, November 7, 2013

Who stole my weeds?

A hilarious news story has been making the rounds recently, about a property owner in Portland, Oregon, who is upset that someone is trespassing and picking the weeds on this property. The story broke on  KATU, a local news station and there are some hilarious comments below it, and then was picked up by Fox News).  The owner is blaming the chefs of neighboring restaurants, and say that not only do they pick the weeds, they leave recipes after them.

To me, this sounds like a April 1 joke (except it wasn't published on the first of April).  First, if you have weeds, wouldn't you be happy to get rid of them?  Second, I doubt chefs would pick weeds in urban lawns that most likely have been sprinkled with pesticides, cat urine, and exhaust fumes plus other unmentionable things.  Third, chefs leaving recipes? This story smells funny all the way from Oregon.  It is possible it is true of course, but that remains to be seen.

search for Urban Edibles in Molenbeek
Urban foraging for edible plants in Belgium. Would you eat the plants from this spot?
Creative Commons photo by foam on Flickr.
However, the idea that chefs would harvest weeds for serving at upscale restaurants are likely and part of a new trend of eating a larger variety of greens, being 'on the edge' of novelty, and of course, being extremely locavorish.  This was already described in the great book Foraged Flavor by Wong and Leroux, and has its roots not only in traditional Italian cuisine with its wild spring greens but also in many other ethnic cuisines.

I grew up picking wild stinging nettles in early spring, when the shoots were small (but still stung).  You had to were gloves, and our patch was so small that only only got enough for one meal per year (or rather, I think we gave up after that).  You cooked the soup down like spinach soup and all the stinginess was gone after boiling, add some cream or milk, and then served with a hard-boiled egg cut in half that floats like two boats in the green sea.  Yummy, and here is a recipe.  The stinging nettles are certainly weeds. 

Monday, October 21, 2013

The good side of an invasive

クズ (Kudzu) 

The non-native species Pueraria lobata, commonly known as kudzu (or sometimes mile-a-minute weed, but it is not the same plant as in this blogpost), is a creeping, climbing legume vine from japan and china. “Kudzu” literally means ‘plant’ in Japanese. Like most invasive species, kudzu is considered a noxious weed in our part of the world. The ecological damage caused by this plant is solely due to its ability to out-compete neighboring species for resources such as light. As it grows over other plants, its large leaves blocks sunlight and often plants beneath the kudzu are suffocated. 
Kudzu, The Vine That Ate the South
"The Vine that ate the south." Kudzu invasion in forest.
Creative Commons image by
Frank DiBona on Flickr.

In its home countries, however, it has proven to be a herbal remedy for a variety of troubles such as hair loss and alcoholism. Such two-sided traits beautifully sum up the contradiction of invasive species. Though malicious in some environments, invasive species can be used to our benefit in other area. As seen in our last post about invasives, significant efforts have been put in to mitigate these weeds. However, recent research has shown that some of their characteristics could be beneficial to society.

How did kudzu get here? In 1876, during the US’ 100th birthday exposition in Philadelphia, the Japanese government constructed a native Japanese garden for the exhibit. The imagery of the leaves appealed to many American gardeners leading to the vast spread of kudzu in local gardens as ornamental plants from a Florida nursery that propagated and sold the plant. Kudzu was also actively promoted as a forage plant and soil conservation plant in the US during 1930s and 1940s. But it didn’t stay in gardens and on roadsides, it quickly escaped and took over the native forest. 

In addition to this, the US Armed Forces used kudzu as camouflage for equipment in Vanuatu and Fiji in the Pacific. Needless to say, the plant has become classified as an “unwanted organism” in these countries too.
The root, flower and leaf from kudzu are used to make herbal medicines. In Traditional Chinese medicine, the use of natural resources is the norm. In fact, the use of herbal-based medication is still a leading treatment for disease in many areas of the world. Kudzu is noted to have been used in Chinese medicine before 600 AD. Its uses range from treatments of menopause symptoms, muscle pain, stomach pain, fever, diarrhea, sinus infections, high blood pressure, to irregular heartbeat, chest pain and various other illnesses.
This medicine features the roots and flowers of the Kudzu plant,
which aims to lessen the desire and craving for alcohol. In addition
it aids the body's natural detoxification processes.
Source: vitaminshoppe.com

Despite its popularity on the Asian continent, the herbal remedy from kudzu has so far lacked sufficient scientific evidence to prove any effects. So can this weed actually help the medical world?

Kudzu promises a remedy for an illness of much importance to society. It has been used to “cure” alcoholism, or more accurately, decrease the symptoms of drinking and the urge to do so. In 2012 Penetar et al published a study conducted at McLean (a hospital affiliated with Harvard University) on kudzu’s effects on alcohol consumption. It was found that physiologically, kudzu can increase the blood flow to the brain and heart. “Wherever blood goes, alcohol goes”, states professor Scott Lukas on the research team. The theory is that this allows for a quicker response time, and the ability for the body to have enough alcohol in less time. Simply put, you get drunk faster on less alcohol. 

First tested on rodents, the intake of alcohol decreased significantly in the lab results when they were given kudzu. When tested on humans, the group treated with kudzu drank significantly less than the placebo group. The research states that alcohol consumption was almost cut in half!  

More research into the how’s and why’s of such effects could lead to very improtant discoveries regarding potential contributions of this invasive species to medicine. 

Check out an old poem written on this historic weed!

Wednesday, October 2, 2013

The minute mile-a-minute mitigator

A minute of natural history

Mile-a-minute overtaking trees.
by Furryscaly via Flickr CC
Mile-a-minute (Persicaria perfoliata) is one of the most pervasive and damaging nonnative invasive plant species in the United States.  Mile-a-minute, a member of the Buckwheat family (Polygonaceae), was first introduced to the U.S. in 1890 from its indigenous range of Asian and Southeast Asia.  The plant did not successfully establish a permanent population in the U.S. until a reintroduction in the late 1930s when a Pennsylvanian nursery germinated Holly seeds from Japan and in doing so, the stowaway mile-a-minute seeds.
Approximate U.S. distribution as of July 2013. Source: Eddmaps.








Mile-a-minute earned its name

Mile-a-minute leaves and ocreae. 
by Leslie J. Mehrhoff
Mile-a-minute is an annual trailing vine with distinctive alternate triangular leaves.  Another identifying trait is the round saucer-shaped structures, or ocreae, which occur at nodes and branching points along the stem.  Self-pollinating flowers and subsequent fruit arise from the ocreae. Recurved barbs along the stem and leaf petioles make this plant particularly unpalatable to most potential herbivores.  Low predation rates in the U.S. coupled with the species’ prolific seed production and readily available dispersal mechanisms (water and birds) are traits characteristic of an exceptionally weedy plant.

Following annual die-back mile-a-minute 
leaves and stems continueto weigh down the 
plants they have climbed & shade groundcover.
by L. J. Mehrhoff via Invasives.org
Most impressing, and most ecologically damaging, is mile-a-minute’s growth rate of up to six inches a day, or 77’ (33.8 m) in a single growing season.  For perspective, mile-a-minute could cover the Statue of Liberty from heal to torch in two growing seasons.  Methods to control this invasive plant include traditional methods of manual removal and chemical pesticide applications.  However, given the rate at which mile-a-minute spreads, traditional methods are not practical of well-established or remote populations.  In 1996, the U.S. Forest Service began researching possible biological control agents.  

Fighting nonnative with nonnative: biological control

Biological control is a way of using an invasive species natural predator or disease, most often from the species’ indigenous region, to reduce the invasives’ proliferation and dominance.  Finding a biological control agent that is truly host-specific to your target species takes a lot of research.  Inadequate research into a control agent’s life history and ecology prior to release may have dire consequences, which are worse than the original cause for their introduction.  A classic example of biological control gone awry is that of Cane Toads introduced to Australia in 1937.  Thankfully, the science of introducing biological control agents has come a long way!

Adult R. latipes are approx. 2mm long.
by Amy Diercks, via Invasives.org
Colpetzer et al. published a study in Biological Control (2004) examining potential biological control agents for use on mile-a-minute.  Results from their study supported the introduction of a small host-specific weevil from Asia, Rhinoncomimus latipes, which feeds on mile-a-minute roots as a larvae and foliage as an adult.  In 2004, the U.S. Department of Agriculture approved the use of the weevil as a biological control agent.  After several regional releases, the introduced weevils have successfully established populations throughout the Mid-Atlantic region. 

Ongoing weevil releases, such as one recently conducted in Union County, New Jersey, help sustain and expand the current weevil populations.  Led by state and county agriculture officials, the recent release of 2,000 weevils in Watchung Reservation, Union County’s largest park, is sure to reduce local mile-a-minute growth in the coming years.

Below is a video from a weevil release in New York City

Amy Diercks, Bugwood.org

Sunday, August 18, 2013

A Texan Turf War

·        Imagine Dallas for a moment. Not the largest metropolitan area with over a million people, but historic Dallas.  I know what you are thinking of  - miles and miles of… turfgrass! Am I right? No?  Well, according to the city planners in Dallas, a nice green lawn is exactly what they had in mind.  A homeowner with a slightly longer view of history has incurred the ire of the Landmark Commission of Junius Heights Historic District for his “historically inappropriate” yard of cacti, yucca, mesquite, agave, and native prairie grasses.

I realize that the city planners want things to look nice – that is, how things looked when they were growing up in the 60’s , 70’s and 80’s – but I have to question the appropriateness of sod in northern Texas.  To begin with, this area was historically covered with mixed prairie: a super diverse mix of grasses, cacti, and yucca. Even if the Landmark commission adheres to a very short view of history, the ecological appropriateness of using dwindling water supplies to support non-native invasive turfgrass seems misguided and foolish. As is the case in many cities in the Southwest, water supply is dwindling, while water demand is skyrocketing. In 2003 the average Dallas citizen used almost 240 gallons of water a day.

 Xeriscaping seems the most appropriate and responsible choice. And prairies can be beautiful! Check out these photos from the largest remnant of pristine tallgrass prairie. Waves of rolling prairie grasses would be a gorgeous addition to suburbia. 

Wednesday, April 3, 2013

Invasive Species Sushi

A Connecticut Sushi chef uses invasive species to re-imagine sushi. Although his dishes showcase invasive aquatic species, his formative experiences were harvesting burdock and lamb's quarters with his mother as a child in New Haven.

How might we re-imagine food using weedy species? Corporate monocultures are arguably as destructive to native habitats as improper fishing practices are in aquatic systems. Many of the cursed weeds of lawns and gardens were once widely considered edible and delicious.

In the comments section of the article, some readers list their own food ideas. Isabel mentions wild mustard greens, purslane, dandelion flowers, kudzu and Japanese knotweed. How do you use weedy plants? Send us your re-imagined weeds salad, tea, or stir-fry recipes!

Wednesday, September 5, 2012

Weed advertising: Verizon

On Verizon Wireless latest poster for their new Samsung smartphone they put a nice fruiting dandelion on the screen. Now why?

Dandelions are kind of like wireless, spread effortlessly with the wind, nearly invisible... Or maybe they just followed the example of the iphone4's poison ivy weed theme..? :)

Species: dandelion, Taraxacum officinale, Asteraceae

Monday, February 20, 2012

Going once, going twice, going invasive!

I just read an interesting article (see citation at bottom) that describes various ways that species become invasive, and if invasive is really a good word to use.   Often there is a lag time between the first introduction until a species becomes common, overwhelming, and invasive.  The author argues that this lag time often is not a result of a biological process, but simply a continuous time for more introductions of the species to the area and human-mediated dispersal. Here are some quotes, laying out this theory:
"A single initial introduction may act as exclusive founding population. In the British Isles, all populations of the highly invasive Japanese knotweed Fallopia japonica are supposed to descend from one single clone probably introduced in 1848."

"Most frequently, however, successful non-native species are introduced repeatedly and often discontinuously over long periods from one or more original ranges into a new one."

"The success of these species was, in terms of naturalisation, poor with 7.4% naturalised. In contrast, 41.2% of the deliberately introduced taxa achieved naturalisation." {this is from a 1912 study in France}
Note the comment at the end, that deliberately introduced and spread taxa are the ones that become invasive, much more so than the accidentals.  The article describes the situation in Germany, but I think you would have a similar case in the US.  Some of our worst weeds were deliberately spread by humans and promoted as solutions to problems (kudzu for soil erosion and multiflora roses for hedges, for example).  Very interesting read.

Article, source for quotes: Kowarik, Ingo. 2003. Human agency in biological invasions: secondary releases foster naturalisation and population expansion of alien plant species. Biological Invasions 5: 293–312, 2003.

Species: Kudzu, Pueraria lobata, Fabaceae.