Sunday, July 29, 2012

Ribbon grass is an invasive native plant





Species name: Phalaris arundinacea

Common name: reed canarygrass, ribbon grass

Location: Ontario

This is one example of a plant where, in hind sight, I wish I had made a species status diagram that included "invasive" as a category with "native". This species of grass, native so Ontario and the surrounding area, is incredibly invasive and downright impossible to eradicate once established (at least, without the use of harsh chemicals). It produces chemicals in the roots that prevent competitors from establishing in the same area, while at the same time being incredibly successful at reproducing both sexually by seed and asexually by thick underground rhizomes. Anyone who has ever tried pulling this plant out of the ground knows about the thick rhizomes! The natural form of this plant is solid green, but horticulturalists have bred this plant to be variegated, which has allowed this plant to become an attractive garden plant, especially for moist garden areas. Despite thriving in boggy areas it is also incredibly drought-tolerant once established, and has also been suggested as a good phytoremediator since it can sequester contaminants from the soil.

The reed canarygrass has also been suggested as a possible candidate for burning as biofuel, since it is so fast-growing. It has recently been used in trials of contaminated soil rehabilitation mimicking the Chernobyl or Fukushima nuclear disasters, to experiment with different plants that can be used to clear contaminants out of the soil. This plant, along with the common sunflower and a few other garden plants, have actually shown great promise. One of the neat things about plants is that they can be genetically manipulated to store radioactive waste in specific parts of its plant body while not in others. This means that, theoretically, you could get a sunflower plant to store radioactivity in its leaves that you could harvest and dispose of safely, while you could also harvest the seeds to be used for food, grain, or for oil production. Since the radioactive waste wouldn't ever make it to the seed, the seed would be perfectly safe for human consumption. I'm not sure how many of us would knowingly eat "Fukushima sunflower seeds" at a baseball game, but it's a neat idea. Still many, many years away from being a viable ecological treatment since so much safety testing must be done. By the time it was approved, I'm sure there would be other ways of remediating the soil that would be favoured instead.

This plant contains incredibly high concentrations of the chemical gramine, which causes brain damage and death in sheep who consume it. This effect isn't always translated to humans, but still probably a good idea to make sure this plant is always out of reach of children and beloved pets. Levels of hordenine have also been reported (a chemical present in high concentrations in germinating barley seeds, but denatured at the high temperatures used in malt production, for those of you who make beer in a home-brew), which act as a central nervous system stimulant by increasing heart rate and blood pressure. This effect is most strongly noted in horses, and the effect appears to subside after 30 minutes (although, it's hard to ask a horse how they're feeling and understand the resulting "speech"). Again, probably a good reason to keep this plant away from small children and pets.