Swallow-wort

Vincetoxicum hirundinaria can reach a height of 30–70 centimetres (12–28 in). Stem is erect, stout and glabrous. Flowers in whorls form a raceme. They have a diamenter of about 1 centimetre (0.39 in). Corolla has five white petals. Calyx is composed by five fused, sharp-pointed sepals. Leaves are opposite, ovate to lanceolate and short-stalked. Fruits reach a length of about 5 cm and contain many seeds showing a tuft of white hairs. Flowering time lasts from June to the end of July.

This species is native to cliffs and slopes, especially in calcareous soils, of continental Eurasia (including some Baltic islands). There are introduced populations in North America (Ontario, Michigan, and New York). It is not present in Great Britain and Ireland.

The generic name Vincetoxicum, in Latin meaning ‘conqueror of poison’, derives from the traditional use of this plant as an antidote to poisons. The Latin species name hirundinaria (from hirundo, meaning swallow) and the common name white swallow-wort refer to its seedpods, that are reminiscent of a swallow's wing, or tail.