Savanna-Whorled Milkweed

Whorled Milkweed

Order: Gentianales

Family: Asclepiadaceae

Genus: Asclepias

Species: A. verticillata

General Characteristics: This native perennial plant is unbranched and up to 2' tall. Whorls of 4-8 linear leaves occur along the slender central stem. This stem is ridged and hairless. Each leaf is up to 3" long and 1/8" across, with a prominent longitudinal vein, and no hairs. The leaves often curve downward from the stem, and then curl slightly upward toward their outer tips. Along the upper half of the plant are short-stalked umbels of greenish white flowers that emerge from the axils of the leaves. These umbels have up to 20 flowers and span about 2-3" across. Each flower consists of 5 strongly reflexed petals that are light green, and 5 white hoods that are arranged around the center of the flower. An individual flower is about 1/3" across. There is little or no floral scent. The blooming period occurs from early to late summer, and lasts about 1-2 months. Later, slender follicles appear where the flowers have been successfully pollinated. These follicles split along one side to release numerous seeds with large tufts of white hairs. The follicles are about 3-4" long and 2/3" across, with a fairly smooth surface. Seed dispersion is by wind. The root system is fibrous and rhizomatous. This plant often forms colonies.

Special Adaptations: This little milkweed blooms later in the year than many other members of the genus, and is good at attracting butterflies. The foliage of this plant resembles a horsetail, but the flowers reveal its membership in the Milkweed family. It can be distinguished from other milkweeds by its skinny whorled leaves and greenish white flowers.