From wandering cattle to dinner table :

Although lovingly named after the Greek goddess of the moon, Selene, this microelement rarely receives much attention.  It’s been labelled as a “heavy metal” by the fertilizer industry but this is a misnomer considering the element is nonmetallic and has chemistry that rather resembles that of sulfur and sulfur containing compounds, not metals. (more on this later)

Research into selenium accumulation by plants started in the 1930s when it was discovered that a number of livestock disorders, namely alkali disease, ill thrift, and blind staggers were associated with the consumption of certain plant species indigenous to seleniferous (selenium containing) soils in western Canada and the USA. The symptoms are characterized by sluggish movement, loss of appetite, and the appearance of blindness.  In spite of the apparent dangers of selenium toxicity, the element is essential for human and animal nutrition and is considered beneficial for certain plant species.  It also happens to be hyper accumulated by some species in the Astragalus, Xylorhiza, and Stanleyea plant families. This puzzling contradiction poses an interesting question: why is it that an element that can have detrimental effects on plant growth and is generally toxic at incredibly low concentrations for most species would be selectively acquired by others?

More on this next week!

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