Sunday, November 7, 2010
Lunaria annua, Honesty
Lunaria annua, commonly known as honesty or money plant, is an example of a species that's more attractive dead than alive. After the flattened fruits, known botanically as siliculas, have shed their seeds the central translucent septum of the silicula remains attached to the plant well into winter and looks especially striking when back-lit by low winter sunlight. The silvery appearance of the discs, resembling coins, accounts for the common names.
After pollination the ovary of honesty develops into a flattened disc-shaped silicula and when it's brightly lit by sunlight you can see the six kidney-shaped seeds developing inside. When it ripens the two outer walls separate from the central septum, the seeds blow away...........
and only the papery central septum remains attached to the plant.
Honesty is a member of the cabbage family, Brassicaciae, whose members typically have four petals arranged in a cross (explaining for the old name of the family, Cruciferae). The purple flowers of honesty aren't especially attractive, unless you happen to be an orange tip butterfly like this one, visiting to collect nectar.