Species Native to Missouri
Common Name: fourleaf milkweed
Type: Herbaceous perennial
Family: Apocynaceae
Native Range: Central and eastern North America
Zone: 5 to 8
Height: 1.00 to 2.50 feet
Spread: 0.75 to 1.50 feet
Bloom Time: May to July
Bloom Description: Purplish-pink
Sun: Full sun to part shade
Water: Dry to medium
Maintenance: Low
Suggested Use: Naturalize
Flower: Showy, Fragrant
Attracts: Butterflies
Tolerate: Deer, Drought, Clay Soil, Dry Soil
Culture
Easily grown in average, dry to medium moisture, well-drained soils in full sun. Tolerates part shade. Best in sunny locations with sandy loams. Drought tolerant. Easily grown from seed, and will self-seed in the landscape if seed pods are not removed prior to splitting open. Likes hot dry soils, but tolerates moist garden soils. Plants have slender rhizomes and may spread to form small colonies but are not considered aggressive. Performs poorly in wet soils. May be difficult to transplant.
Noteworthy Characteristics
Asclepias quadrifolia, commonly known as fourleaf milkweed or whorled milkweed, is an upright single-stemmed herbaceous perennial that typically grows to 1-2 1/2’ tall. It is native to dry, rocky, open woods, often inhabiting slopes and ridges, from New Hampshire to Ontario to Minnesota south to Arkansas, Alabama and Georgia. The leaves (to 2-6” long) are egg-shaped to lanceolate. Mid-stem leaves typically appear in one or two whorls of 4 with opposite pairs of leaves often appearing both above and below the whorled leaves. Like all milkweeds, the stems and leaves produce a milky sap when cut. Tiny fragrant flowers (each to 1/4” long) bloom late May to July in hemispherical terminal umbels. Each flower has 5 sepals (lobed calyx), 5 pale purplish-pink petals (lobed corolla) and 5 cup-like white hoods with incurved horns protruding from each hood. The 5-lobed corolla curves backward and downward toward the center of the umbel, displaying the 5 hoods which are in general a key diagnostic feature of milkweed family plants. Flowers give way to smooth, narrow seed pods (to 3” long) which split open when ripe to release numerous silky-tailed seeds for dispersal by the wind.
The charismatic and imperiled monarch butterfly requires milkweed plants in order to survive. Monarchs migrate into the eastern U.S. from Mexico in spring to lay their eggs on milkweed species plants. Caterpillars hatch from the eggs and consume the milkweed plant foliage as food for growth and development. Mature caterpillars will search for a nearby, sheltered location to enter the pupal stage and form a chrysalis. Inside, they will complete metamorphosis and emerge as an adult butterfly in around 2 weeks. Flower nectar is consumed by adult butterflies as a valuable food source. The 4th or 5th generation of monarch butterflies that emerges in August-September will migrate into Mexico to overwinter as adults. Significant declines in monarch butterfly populations in North America over the course of the 21st century are believed by many experts to be caused by a reduction in milkweed due to widespread use of herbicide-tolerant row crops, climate change, and loss of overwinter sites due to habitat destruction.
To support monarch butterflies, plant species of milkweed that are native to your area.
Genus name honors the Greek god Asklepios the god of medicine.
Specific epithet comes from Latin meaning leaves in fours in reference to the mid-stem leaves of this species which typically appear in whorls of four.
Common names of four-leaved milkweed or whorled milkweed are also in obvious reference to the mid-stem leaf whorls.
Problems
No serious insect or disease problems. Aphids can be problematic but attempting to control them can result in inadvertent harm to monarch caterpillars and other beneficial insects.
Uses
Butterfly gardens, meadows, prairies, or naturalized/native plant areas. Borders. Cottage gardens. Rock gardens.
Seed pods are valued in dried flower arrangements.