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 will spread by rhizomes but are not considered invasive. Performs poorly in wet soils. Difficult to transplant because of deep roots.
Noteworthy Characteristics
Asclepias quadrifolia, commonly known as whorled milkweed or four-leaf 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.
Milkweed plants (Asclepias genus) are particularly noted for their unique and complicated flower structure, the thick milky juice which oozes from broken stems and leaves, their long pointed seedpods, and the almost magnetic attractiveness of their flowers to butterflies and moths.
Whorled milkweed 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. 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 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.
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.
It should be noted that the monarch butterfly, possibly the best known butterfly in North America, needs milkweed plants in order to survive. Monarchs migrate into the 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 next spin a chrysalis which hangs on a milkweed stem until it later emerges, through the miracle of metamorphosis, as an adult butterfly. Flower nectar is consumed by adult butterflies as a valuable food source. The adult butterfly eventually migrates into Mexico for winter. Recent significant declines in monarch butterfly populations in North America are believed by many experts to be related to a corresponding significant decline in milkweed plants which in large part has been caused by an increased use of glyphosate herbicides around food crop areas where glyphosate-tolerant (Roundup Ready) crops are being grown.
Problems
No serious insect or disease problems. Watch for aphids.
Uses
Butterfly gardens, meadows, prairies, or naturalized/native plant areas. Borders. Cottage gardens. Rock gardens.
Seed pods are valued in dried flower arrangements.