Asclepias quadrifolia aka Four Leaf Milkweed

Asclepias quadrifolia is known as fourleaf milkweed. It is a perennial, so it lives for years. It belongs to the dogbane family, Apocynaceae. Its native range covers southeastern Canada. It also covers much of eastern and north-central America. It grows in open woods and at woodland edges. It also grows on rocky slopes, in disturbed fields, and along roadsides.

Plants tend to reach 1–2.5 feet [0.30–0.76 metres] tall. Some garden plants reach 3 feet [0.91 metres]. Spread ranges from about 1.5–2 feet [0.46–0.61 metres]. Each plant has one upright stem, which may turn purple. The stem has a flat side and can bear hairs. Thin green leaves have smooth edges and narrow bases. Leaves range from egg-shaped to narrow with pointed tips. Four leaves form a whorl, or ring, near the stem's middle. Leaves above and below these whorls may grow in pairs. Broken leaves and stems release milky sap. Thin rhizomes, or underground stems, can form small groups of plants. They do not spread too strongly.

Small, scented flowers form round clusters called umbels at stem tips. The flowers can be pink, lavender, or white. Pale pink lobes surround white hoods in each flower. Bloom runs from May to July. Chicago Botanic Garden also notes blooms into August. Bees, butterflies, and moths visit the plant for nectar. Monarch and milkweed tussock moth larvae also use it as a host. Green seed pods, called follicles, form after bloom. They then dry and swell. Each pod holds many seeds with white hair tufts. Gardeners use the pods in dried flower displays.

Grow this milkweed in full sun or partial shade. It favors sandy loam but tolerates clay and rocky ground. Acid to neutral soil suits it. Good drainage matters more than rich soil. It copes with drought and dry ground. It also grows in moist garden soil. Wet soil leads to poor growth. Sources place it in USDA zones 5–8. It needs little care and grows easily from seed. Plants can self-seed when ripe pods split. Plants may be hard to move once they take root. Use it in borders, rock gardens, meadows, and native plantings.

Serious disease is rare. Aphids may cause trouble, but sources differ on their impact. Milkweed bugs can cause great harm to seed pods. Aphid control can also harm monarch larvae and useful insects. Cherokee people used this plant's fibers to make bowstrings. Folk use reports include root tea and leaf treatments for warts. These reports do not prove it is safe as medicine. Eating large amounts can upset digestion and cause weakness and confusion. The plant poses risks to people, dogs, cats, and horses. Its sap can irritate skin and eyes. Evidence for this species does not show that any parts are edible.