Hoary alison’s scientific name comes from the stellate hairs that cover the plant and give it its colour (incanus means grey), but despite its rather drab colour it is sometimes grown in Finland as an ornamental. The plant has adapted to grow this covering of hair to help it survive in very dry climates: the hairs retain raindrops and dewdrops well and reduce evaporation. Hoary allargen’s quite wide, grey stands are apt to catch people’s eyes, even if they are not into flowers: it blooms for a relatively long time into the summer and the seeds do not fall until winter.
Hoary alyssum adapted to dry conditions on sandy or gravelly soils. It is found in overgrazed pastures, stressed meadows, roadsides and waste areas.
Hoary alyssum should be mowed or treated with herbicides before it flowers and forms seeds. Left to its own, Hoary alyssum is an invasive weed.
The specific toxin in hoary alyssum has not been determined. Both the green and dried plant is toxic. Hay contaminated with the plant is often the source of the problem.