Apocynum androsaemifolium aka Spreading Dogbane

Apocynum androsaemifolium, or spreading dogbane, is a perennial wildflower. It belongs to the dogbane family, Apocynaceae. Its native range runs from subarctic North America to northeastern Mexico. It grows in woods, along woodland edges, and in open grassland. It also occurs in meadows and fields across North America. The plant loses its leaves in autumn and has a bushy, branching form.

Garden plants reach about 2–3.3 feet (0.6–1 metre) tall. Sources differ on width. RHS lists up to 1.6 feet (0.5 metres). NC State gives 3–4 feet (0.9–1.2 metres). Underground rhizomes spread fast, so small gardens may not suit it. Smooth, round stems range from pale green to red. They hold a milky sap. Oval leaves grow in pairs along the stems. Their edges are smooth, and their tips come to points. The lower surface is paler and may bear hairs. Leaves turn yellow before they fall.

Small pink flowers hang in clusters near the branch tips. Each bell-shaped bloom has darker pink stripes within. The flowers have a scent and supply nectar to pollinators. Bloom starts in May or June and lasts into August. Butterflies visit the flowers, but monarch larvae cannot survive on this plant. Bees use dead, hollow stems as nest sites. Long, narrow fruits called follicles follow the flowers. They reach 0.25–0.5 feet (0.08–0.15 metres) in length. Ripe pods split and release seeds with tufts of hair. Wind carries the seeds away.

Grow it in soil that drains well, in sun or part shade. Chicago Botanic Garden also lists full shade. It tolerates drought and grows in dry to moist conditions. Sandy, rocky, chalky, and loamy soils can suit it. It accepts acid, neutral, or alkaline soil. Sources list USDA zones 3–9 and UK hardiness H6. It fits woodland, prairie, wildlife, and naturalized plantings. RHS reports few pest or disease problems and no need for pruning. Its spread can make it weedy or locally invasive.

Native Americans used its fibre to make thread. The bark also yields fibre for twine and bags. The plant has a history of medicinal use, but it is not food. All parts are poisonous if eaten. Poisoning can cause vomiting, diarrhoea, weakness, and severe heart problems. The sap can blister skin, so handling calls for protective gear. It is also toxic to dogs, cats, and horses.