Overview
The Silver Dollar Plant (Lunaria annua), also globally known as Honesty, Money Plant, or Moonwort, is an enchanting biennial flowering herb in the mustard family (Brassicaceae). While adorned in spring with attractive clusters of fragrant violet-purple blooms, it achieves worldwide fame in autumn when its flattened, circular seed pods shed their outer husks to reveal shimmering, paper-thin silvery membranes that glisten like polished silver coins in the sun.
Biology and Physical Characteristics
Growing up to three feet tall on erect, branching bristly stems, Lunaria annua bears large heart-shaped, coarsely toothed leaves. In late spring of its second year, it produces fragrant four-petaled flowers ranging from deep magenta to lavender-violet. Following pollination, it forms large, paper-thin, oval-to-circular seed pods (silicles). When the seeds drop in autumn, the persistent central membrane (replum) remains attached to the dried stems as a luminous, translucent silver disc.
Behavior and Ecology
During its spring flowering phase, Lunaria annua provides a critical early nectar and pollen resource for emerging native bumblebees, honeybees, and butterflies, particularly the Orange-tip butterfly (Anthocharis cardamines) which utilizes it as a larval host plant. As winter approaches, the dried papery membranes flutter in the wind, catching breezes to disperse seeds through anemochory across open woodlands and riverbanks.
Conservation and Human Impact
Evaluated as Least Concern on the IUCN Red List, the Silver Dollar Plant is widespread, adaptable, and completely secure throughout its native European range and naturalized ranges in North America and Australasia. Revered for centuries in folklore as a symbol of honesty and prosperity, its dried silver-dollar stems are globally prized in floral arrangements and cottage garden botanical craftwork.
Interesting Factoid
The translucent central membrane of the dried seed pod has an iridescent, mother-of-pearl sheen that allows sunlight to pass completely through it, earning it the botanical name ‘Lunaria’ from the Latin for ‘moon-like’.
Last updated: October 2026