Echium plantagineum is an invasive, non-native species that is considered a noxious weed in Australia. Because it grows so quickly and well in pasture, it competes with livestock forage. To make it worse, it is toxic to livestock in high quantities. For these reasons, the plant was named “Paterson’s Curse”. CSIRO calls it Australia’s “worst broadleaf temperate pasture weed“.
However! Australia is known for its decade-long droughts, and E. plantagineum is hardy and drought tolerant. When all other forage is long dead, this plant at least provides something for the livestock to eat. Hence, its other name “Salvation Jane”.
In addition to this rescue effect, the plant is highly valued among apiarists in Australia. Honeybees love it and from it they make a premium grade honey that, at one time, comprised 10-15% of the the honey crop of the continent (Cullen & Delfosse 1984).
In the 80′s the opposing positive and negative effects of this weed caused a huge controversy. On one side of the debate were the livestock farmers, who demanded the introduction of biocontrol agents that would hopefully lead to the eradication of the weed. On the other side were the beekeepers, who lobbied to prevent the introduction of the biocontrol agents.
Eventually, the livestock managers won out and the biocontrol agents were introduced. E. plantagineum is still a weed today, though. As usual, the biocontrol agents weren’t 100% successful in eradicating it. However, land managers have hope that, as the six introduced biocontrol agents spread throughout the plant’s distribution, they will help to reduce population densities for easier control.
The fascinating thing about this story (to me), is the balance between the negative and positive effects of this one plant; it was able to divide a country.
I think we often run into this problem (which I fondly call the Taxonomist’s Fallacy)…we tend to lump species into categories: native, not native. Good, bad. Weed, crop. But the point is that they have multifaceted ecological roles, they might compete with other plants, but at the same time they provision bees with resources! Is this plant a salvation or a curse? Both!
How do you account for a plant that has both vices and virtues?