Hoary alyssum is native to Asia and parts of Europe, but it has become naturalized in North America
and other areas in Europe.
It is now widespread, and often considered to be an invasive. It is a member of the mustard family.
Bees, who, unlike us, can see ultraviolet light,
have probably noticed that
hoary alyssum buds glow in ultraviolet light. Curiously, it is the buds, not the flowers.
Identification: Hoary alyssum creates a loose tangle of stems
lined with small grasslike leaves near the base, fruits along the upper portion, and a small cluster
of white flowers on the top. Stems may reach up to 3' (1 m) in length, and are rarely branched.
Leaves are alternate, 1¾-3" (5-8 cm) × ⅜" (1 cm), narrowly rounded at the tips. Flowerheads
are composed of many small flowers. Each flower contains four petals, but they are so deeply notched
that they appear to be eight petals. Petals are ⅛-¼" (5-7 mm) long, with thick yellow-green stamens. Fruits are tiny ovals, or
cylinders with rounded ends, ⅛" (3.2 mm) long, with sharp tips. Fruits are on short stems
less than ¼" (6.3 mm) long, oriented along the direction of growth.
Edibility: Poisonous Well, poisonous if you are a horse,
anyway. About half of the horses that eat this plant react with swelling, fever, elevated heart rate,
and rarely death. Other serious symptoms have been reported. I couldn’t find specific information about toxicity to people, but I’m
not about to sample it.