About Matelea baldwyniana (Sweet) Woodson
Matelea baldwyniana (Sweet) Woodson is a perennial herbaceous vine that either climbs or trails across other vegetation, growing to around 3 meters (10 feet) in height. Its stems are brownish, covered in hairs, and produce milky sap. The leaves are green, broadly ovate, arranged oppositely along stems, and have smooth margins. Leaf blades measure 5–16 cm (2.0–6.3 in) long, and attach to hairy petioles that are 5–6 cm (2.0–2.4 in) long. Flowers grow in clusters of 15 or more on long peduncles; each flower is white, with a disc-like central column that holds five anthers, plus five twisting white petals joined at their base. Seed pods are 6.5–9 cm (2.6–3.5 in) long, and contain flat, round seeds that bear many long white hairs, just like seeds of other milkweeds. This species is native to the central and southeastern United States, occurring in Oklahoma, Arkansas, Missouri, Mississippi, Alabama, Georgia, and Florida. Most populations are found in Arkansas and Missouri, while the species only occurs as isolated populations or is known from historical records in the other listed states. It grows in forest clearings, closed canopy woods, ravine slopes, glades, and savannas. Flowering takes place from April to June, and Matelea baldwyniana acts as a host plant for monarch butterfly caterpillars.