Plants that bite

There is only one plant I know of that would actually bite you and that is the Venus Fly Trap. A bite from that plant would not be painful or even leave a bite mark. The four plants you will read about here all grow in this area and can cause mild to severe skin rashes resulting in pain, suffering, medicated creams and prescriptions.

Poison Ivy is generally the first poisonous plant that people think of. The old saying, "leaves of three let me be," refers to the three leaflets that make up one leaf. Other plants such as raspberry and boxelder have leaves that can easily be confused with Poison Ivy.

Poison Ivy plants can grow in the form of a small plant, a small bush or tree and even a vine that climbs high into trees. Virginia Creeper is another vigorous vine that climbs trees; however, it has five leaflets and is not harmful. All parts of the Poison Ivy plant contain urushiol oil that, when touched, spreads quickly on the skin due to the oily nature. Urushiol oil is very potent. One nanogram (one billionth of a gram) can cause a rash on human skin!

Poison Hemlock is a magnificent plant that found its way to ditches and fence lines in just the last few decades. I call it magnificent because it has large, shiny, beautiful, fern-like leaves. This plant is symmetrical and can grow 6 to 8 feet tall. In June, clusters of tiny white flowers appear followed by light brown seeds. All parts of this plant are poisonous to people and livestock. If you mow this plant down, be careful that juice from the stems don’t touch your skin. Blisters can form that look similar to Poison Ivy rash.

Wild Parsnip has been a common weed in the area for as long as I can remember. In the last 10 years, it has become an invasive weed in many parts of North America. It has been crowding out other friendlier ditch plants like the Foxtail and Brome grass. This plant will grow up to 5 feet topped with tiny yellow flowers in a flat, open cluster. The sap from this plant contains chemicals called furanocoumarins which, when exposed to sunlight, can cause a severe burn within 24 to 48 hours.

The fourth plant on my list can actually be eaten! Stinging Nettle when picked young can be used in salads, cooked like spinach, or steeped as a healthful tea. The problem arises when this plant gets bigger and matures. Hair-like barbs on the stems and leaf veins contain an irritant that feels like a bee sting if they touch bare skin. It is a sharp stinging pain that will go away in 10 to 15 minutes. It generally does not cause a lasting painful rash like the other plants mentioned above.

So how do you protect yourself when hiking out in nature? First and most important is to educate yourself and be able to identify these plants. Look them up and share the information with your family and friends. Then go out and try to find these plants so you know what they look like in their own home turf. Second, dress appropriately for your outdoor activity. A long-sleeved shirt and long pants with hiking boots and socks will protect you from poison plants and also ticks, mosquitos and gnats. Third, if your skin is exposed to poison plants, do not spread it by scratching or wiping your face with your hand. The oil can be easily spread, especially if you wipe sweat off your brow.

If you are "bitten," wash the exposed area with clean soapy water as soon as possible. Rinse with clear cool water. Launder your clothes to remove any residual oil. Consult a pharmacist for creams to use or seek medical help if a serious rash forms. And remember, "leaves of three let me be."

Best plants to grow in pots

There are all sorts of great reasons to grow plants in pots. You might live in a condo or townhouse with limited outdoor space. Perhaps the soil quality in your yard is poor. Or you may love the lush look of potted plants clustered around your patio or outdoor living room. Whatever your situation, find out more about the best plants to grow in pots — and the best pots to grow plants in.

Best plants to grow in pots: General tips

— The best plants for potting are those without a deep root system. Look for dwarf species or compact specimens that tend to grow upward rather than spreading outward.

— Choose plants that will do well with the amount of sun available. A balcony or deck attached to your house may offer only limited sunshine. A roof garden, on the other hand, could provide extremely strong sun, so you'll have to create some shade. Wheeled pots allow you to position your plants to catch the rays they need.

— Combine an assortment of plants in one oversize pot (or several smaller ones of different heights) for the most attractive effect. Find out what your chosen species want to do — for instance droop, clump, or climb — and mix and match accordingly.

— Consider the level of care that the plants you fancy will need. Is it compatible with your schedule and gardening skills? If not, you may want to find a professional gardener to look after your mini-landscape.

Types of plants to grow in pots

Vegetables. Most fast-growing, upward-climbing vegetable species are excellent for container gardening. Easy types to try are beans (bush beans are best), zucchini or summer squash, tomatoes, and bell peppers. NOTE: You'll need a support system ... which could be as simple as a nearby porch railing. Greens like lettuce and spinach also do well in pots.

Flowers. Go for maximum beauty, minimum maintenance. Flowers that are perennials in tropical climes (or invasive) tend to be hardy — perfect for your purpose. If you're a newbie (or even if not), geraniums are the no. 1 flower for potting. Not only do these hardy blooms thrive in containers, they provide a gorgeous array of color, delicate white to deep scarlet. Bring your potted geranium inside before the first frost, place in a sunny window, and it can live for years.

Fruit trees. Yes, fruit trees. They add so much to even a small outdoor space — good looks and with the right TLC, good eating too. Dwarf varieties are best for the confines of a pot. Check whether the fruit tree is self-fertile (such as citrus, peaches, and apricots — best if you only have room for one) or needs a partner for pollination (like apples and pears).

Best pots to grow plants in

Size. Plant pots must be deep enough to accommodate a root system — anywhere from 6-8 inches for most herbs, to 18-24 inches for a miniature tree. Potting soil is expensive, so you can add filler to the bottom third; crumbled Styrofoam works well. Make sure the base is broad enough that the pot won't tip over.

Material. Ceramic planters are ideal but tend to be pricey. UV resistant plastic pots are another option. If you want to get creative, follow the suggestion of Rodale's Organic Life and use galvanized trash cans or wooden barrels for large plantings.

Drainage. Whatever your container, ensure you have adequate drainage. Drill holes in the bottom, if necessary. Safeguard your floor, windowsill, etc., against the resulting runoff and condensation so it won't stain — or rot, in the case of a wooden deck. A saucer under the pot is a good start (TIP: water into the saucer, not the pot itself, for better absorption), but terracotta “pot feet” add an extra layer of protection.

Watering. FACT: Plants need more water in pots than in the ground. Cut down watering needs by topping the soil with mulch; great gardeners I know create decorative mulch from acorns, wine corks, or seashells. If you're planning a large-scale container garden, a drip watering system is a convenient option. For just a few potted plants, self-watering containers will reduce your workload and are handy if you're often away from home.

Research Brief: Grassland plants react unexpectedly to high levels of carbon dioxide

Plants are responding in unexpected ways to increased carbon dioxide in the air, according to a twenty-year study conducted by researchers at the University of Minnesota and published in the journal Science. For the first 12 years, researchers found what they expected regarding how different types of grasses reacted to carbon dioxide. However, researchers' findings took an unanticipated turn during the last eight years of the study.

Researchers planted 88 plots with two different types of grasses, warm-season C4 grasses and cool-season C3 grasses, and exposed them to different levels of carbon dioxide, current carbon dioxide levels and the elevated levels the Earth might experience later this century due to human activity.

"Because carbon dioxide is needed by plants to grow, we expected grasses that have the C3 photosynthetic pathway to grow more under elevated CO2, because these plants are known to be able to increase their CO2 capture as CO2 levels rise. We also expected that growth of grasses with the C4 photosynthetic pathway would not be affected by higher CO2 levels, because these plants are generally less able to capture extra CO2 as CO2 levels rise," said University of Minnesota Professor Peter Reich. "While that held true for the first dozen years, that pattern changed."

Researchers found that during the last eight years of the study, C4 plant species grew more in an elevated CO2 environment than C3 plants. While it's uncertain why this shift happened, these findings could have significant implications.

"If mature grasslands worldwide behave like our experiment did, this could have long lasting impacts on how we think about the conservation and restoration of grasslands around the world," Reich said. "Grasslands cover between 30 and 40 percent of land and play a key role in soaking up carbon dioxide released by burning fossil fuels."

Along with impacts on conservation and restoration planning, these data could be used to help computer models better predict how plants will respond to changing CO2 concentrations in the atmosphere.

"Our results suggest that the predictions made by these models might not be quite right and that we should not be overly confident about our assumptions regarding where, and by how much, land ecosystems will keep absorbing extra CO2 out of the air," Reich said.

Reich, a professor with the College of Food, Agricultural and Natural Resource Sciences' (CFANS) Department of Forest Resources and Institute on the Environment (IonE) fellow, was the lead researcher on the study. Other study investigators included Professor Sarah Hobbie and graduate student Melissa Pastore, with the Department of Ecology, Evolution and Behavior in the College of Biological Sciences, and Professor Tali Lee from the University of Wisconsin, Eau Claire.

About University of Minnesota College of Food, Agricultural and Natural Resource Sciences

The University of Minnesota College of Food, Agricultural and Natural Resource Sciences (CFANS) brings science-driven innovators together to discover hands-on solutions to global challenges. With 10 research and outreach centers across Minnesota, the Minnesota Landscape Arboretum, and the Bell Museum of Natural History, CFANS offer unparalleled experiential learning opportunities for students and the community. CFANS students enter career fields with some of the best job outlooks in the country, including 13 undergraduate majors and more than 25 minors ranging from agricultural education and marketing communications to conservation biology and forest and natural resource management, health and nutrition, to the future of food and agriculture management with a focus on business and technology.

Plants really do feed their friends

"For more than a century, it's been known that plants influence the makeup of their soil microbiome, in part through the release of metabolites into the soil surrounding their roots," said Berkeley Lab postdoctoral researcher Kateryna Zhalnina, the study's lead author. "Until now, however, it was not understood whether the contents of this cocktail released by plants was matched by the feeding preferences of soil microbes in a way that would allow plants to guide the development of their external microbiome."

The study, "Dynamic root exudate chemistry and microbial substrate preferences drive patterns in rhizosphere microbial community assembly," has just been published in the journal Nature Microbiology. The corresponding authors were Berkeley Lab scientists Trent Northen and Eoin Brodie.

Microbes within soil improve the ability of plants to absorb nutrients and resist drought, disease, and pests. They mediate soil carbon conversion, affecting the amount of carbon stored in soil or released into the atmosphere as carbon dioxide. The relevance of these functions to agriculture and climate are being observed like never before.

Just one gram of soil contains tens of thousands of microbial species. Scientists have long known that plants impact the composition of the soil microbiome in the area surrounding their roots by sending out chemicals (metabolites). Prior work by Mary Firestone, Berkeley Lab faculty scientist and a professor of microbiology at UC Berkeley, had shown that plants were consistently selecting or suppressing the same types of microbes over time in the root zone, suggesting some form of synchronization between plant and microbiome development.

Yet, little research had gone into the relationship between specific metabolites that plants release and the microbes consuming them. The new study brought together experts in soil science, microbial and plant genomics, and metabolomics to explore these potential metabolic connections. Their study took a close look at the rhizosphere of an annual grass (Avena barbata) common in California and other Mediterranean ecosystems.

The Berkeley Lab team felt the time was ripe for doing so. As pressure mounts for farmers to grow enough healthy crops to meet a burgeoning population's needs, and for new land management strategies that improve soil carbon storage to reduce atmospheric CO2 and produce healthy soils, the soil microbiome is the subject of more in-depth scientific research than ever before.

The researchers set out to determine the relationship between microbes that consistently bloomed near the grass roots and the metabolites released by the plant. Their first step was to collect soil from the University of California's Hopland Research and Extension Center in northern California. Brodie, deputy director of Berkeley Lab's Climate and Ecosystem Sciences Division, and his group used what they knew about the lifestyles of these soil bacteria to develop specialized microbial growth media to cultivate hundreds of different bacterial species. They then selected a subset that either flourished or declined as roots grew through the soil.

This collection of microbes was then sent to the Joint Genome Institute (JGI), a DOE Office of Science User Facility, where their genomes were sequenced to provide clues as to why their responses to roots differed. This analysis suggested that the key to success for microbes that thrived in the rhizosphere was their diet.

Northen, senior scientist in Berkeley Lab's Environmental Genomics and System Biology Division, is fascinated by the chemistry of microbiomes, and his group has developed advanced mass spectrometry-based exometabolomic approaches to elucidate metabolic interactions between organisms. Zhalnina and Northen combined their expertise to identify what the more successful microbes surrounding the roots of the Avena grasses preferred to eat.

Using a hydroponic setup at the JGI, they immersed plants at different developmental stages in water to stimulate them to exude their metabolites, then measured the metabolites being released by the plants using mass spectrometry. Subsequently, the cultivated soil microbes were fed a cocktail of root metabolites, and the researchers used mass spectrometry to determine which microbes preferred which metabolites.

They found that the microbes that flourished in the area around plant roots preferred a diet more rich in organic acids than the less successful microbes in the community.

"Early in its growth cycle, the plant is putting out a lot of sugars, 'candy', which we find many of the microbes like," Northen said. "As the plant matures, it releases a more diverse mixture of metabolites, including phenolic acids. What we discovered is that the microbes that become more abundant in the rhizosphere are those that can use these aromatic metabolites."

Brodie describes these phenolic acids as very specific compounds released by plants throughout their development. Phenolic acids are often associated with plant defenses or plant-microbe communication. This indicates to Brodie that as they establish the microbial community within the rhizosphere, plants could be exuding metabolites like phenolic acids to help them control the types of microbes thriving around their roots.

"We've thought for a long time that plants are establishing the rhizosphere best suited to their growth and development," said Brodie. "Because there are so many different types of microbes in soil, if the plants release just any chemical it could be detrimental to their health.

"By controlling the types of microbes that thrive around their roots, plants could be trying to protect themselves from less friendly pathogens while promoting other microbes that stimulate nutrient supply."

Zhalnina, Firestone, Northen, and Brodie believe their findings have great potential to influence additional scientific and applied research. Zhalnina points out that a lot of research and development is currently underway by government and industry to harness the power of microbes that improve plant yield and quality of soil to help meet society's growing demands for a sustainable food supply.

She said, "It's exciting that we can potentially use the plant's own chemistry to help nourish beneficial microbes within soil. Population growth, especially, has created a demand for identifying more reliable ways to manipulate the soil microbiome for beneficial outcome."

How plants 'muscle up' against bacteria in the cold

Michigan State University scientists have furthered our understanding on how a plant protein, called CAMTA, helps plants strengthen themselves as they anticipate long periods of cold, such as three to four months of winter in the American midwest or northern Europe.

The long-term goal behind the research is to breed or create plants with higher tolerance to wild swings in temperature. The study is published in the journal The Plant Cell.

CAMTA proteins are universally found across plants, and they help turn on genes that communicate freezing tolerance to these plants. In the study, CAMTA proteins were observed to also control how plants defend against harmful bacteria under long-term cold conditions.

In the cold, plants generally build up high levels of salicylic acid, or SA, a compound that protects them against bacteria.

"At warm temperatures CAMTA proteins, specifically the N-terminus (the start of the proteins), block the system that produces SA," said Yong Sig Kim, a post-doctoral student in the lab of University Distinguished Professor and MSU Foundation Professor Michael Thomashow.

When it gets cold for a long enough period, an unknown signal is generated that modifies CAMTA to allow SA production to turn on. In that case, the C-terminus, or the bottom of an amino acid chain that is stopped by a free carboxyl group, detects the signal -- possibly a rise in cellular calcium levels -- that enables SA biosynthesis.

This observation reverses current accepted models, which proposed instead that the C-terminus blocked SA production.

Why does tolerance to the cold instigate bacterial defenses?

"SA doesn't protect the plant from the cold, per se. Instead, we think the plants enhance their immune systems in the cold as a general preemptive strategy," Kim said.

Although plants take measures to survive the cold, they still get injured, and their structures are destabilized, which makes them more vulnerable to bacterial infection.

So, weakened plants keep their guard up as a precaution. It is similar to how humans take preventative measures to stay healthy – eat well, sleep eight hours, hydrate, etc.

This knowledge has long-term potential impact on agricultural production. For example, according to the EPA, in 2010 and 2012, high nighttime temperatures affected corn yields across the U.S. Corn Belt, and premature budding due to a warm winter caused $220 million in losses of Michigan cherries in 2012.

 "The field of plant defense is gradually revealing how protection mechanisms against the elements and against other living beings are interrelated," Kim said.