Milkweed in the context of "Acanthocephala terminalis"

In botany, a follicle is a dry unilocular fruit formed from one carpel, containing two or more seeds. It is usually defined as dehiscing by a suture in order to release seeds, for example in Consolida (some of the larkspurs), peony and milkweed (Asclepias).

Some difficult cases exist however, so that the term indehiscent follicle is sometimes used, for example with the genus Filipendula, which has indehiscent fruits that could be considered intermediate between a (dehiscent) follicle and an (indehiscent) achene.

Danainae is a subfamily of the family Nymphalidae, the brush-footed butterflies. The group may be referred to as the Danaids (reflecting their previous rank as a family) or milkweed butterflies, as they often lay their eggs on various milkweeds on which their larvae (caterpillars) feed, though it also encompasses the clearwing butterflies (Ithomiini), and the Tellervini.

Some 300 species of Danainae exist worldwide. Most of the Danaini are found in tropical Asia and Africa, while the Ithomiini are diverse in the Neotropics. Tellervini are restricted to Australia and the Oriental region. Four species are found in North America: the monarch butterfly (Danaus plexippus), the queen (Danaus gilippus), the tropical milkweed butterfly (Lycorea halia), and the soldier butterfly (or "tropic queen", Danaus eresimus). Of these, the monarch is by far the most famous, being one of the most recognizable butterflies in the Americas.

Asclepias incarnata, the swamp milkweed, rose milkweed, rose milkflower, swamp silkweed, or white Indian hemp, is a herbaceous perennial plant species native to North America. It grows in damp through wet soils and also is cultivated as a garden plant for its flowers, which attract butterflies and other pollinators with nectar. Like most other milkweeds, it has latex containing toxic steroids, a characteristic that repels many species of insects and mammals.