Most plants in the genus start out male and later change to female. Plants can have flowers of both sexes on one plant, or all male or all female, and can change from year to year. It is thought that this adaptation helps preserve the strength of the plant in drought years, when male flowers are produced to save the energy required to form seed. Arisaema tubers and seeds contain a compound called calcium oxalate, composed of tiny glasslike splinters that cause an intense burning and swelling when ingested. Skin can be burned from handling the bruised seed.
Seed is produced in shiny berries atop the naked stem once the hood has withered away.
Shaped sort of like a pine cone, the green berry cluster turns to a lacquered red in autumn and usually stands alone, the leaves having faded away. Arisaemas are easy to direct sow in the garden, but fresh seed is a must. First year seedlings are one-leaf affairs, the second year is spent building up the corm, and the third year usually produces a flower, though some species may take five years to flower. Connie Buchanan, an avid shade gardener, invited me over to see her collection, which includes several Arisaemas. They are both strange and beautiful at the same time, and any misgivings I had about their weirdness soon gave way to complete fascination.