Vicia bithynica

An annual with climbing stems, scrambling or climbing to about 60 cm tall. The leaves are arranged alternately along the stem, are up to about 9 cm long, have 2–3 pairs of leaflets, and end in branched tendrils. The petioles are 2 cm long with a large, ovate, dentate stipule at the base. The flowers are arranged in pairs (although sometimes solitary) on long (5 cm) peduncles branching from the leaf axils. The petals are purple and white, 2 cm long, and have 10 stamens and 1 style. The fruit is a hairy pod or legume up to 5 cm long with 4 to 8 seeds.[1] It has 14 chromosomes.[1][3]

Vicia bithynica is not cultivated for human or livestock consumption. The seeds contain high levels of vicine,[4] which causes favism amongst susceptible individuals.[5]

The habitat of V. bithynica is often described as ‘woodland and scrub’ but Bennett & Maxted[6] examined many herbarium specimens for habitat data and concluded that it was most common in calcareous grassland, while others[7] describe it as a weed of agricultural fields. In Greece, it is a native therophyte of dry scrub (phrygana) and grassland.[8]

In Britain, at the northern extremity of its range, it is considered to be a plant of coastal undercliffs, the backs of beaches, bare ground, hedges and old railway lines.[9]

Vicia bithynica is widespread around the Mediterranean and in Europe as far north as Scandinavia, and there are isolated populations in the Azores, United States, Australia and New Zealand.[10]

It is common in Turkey and considered to be native there,[3] as it is in Malta,[11] becoming rarer further north. In Britain it is classified as Vulnerable[12] and is declining in abundance,[13] although it is protected in several sites of special scientific interest such as Sheppey Cliffs and Foreshore and Swanscombe Peninsula.[14]