''Lathyrus niger'', also known as black pea, blackening flat pea and black bitter vetch, is a perennial legume that is native to

Europe Europe is a large peninsula conventionally considered a continent in its own right because of its great physical size and the weight of its history and traditions. Europe is also considered a Continent#Subcontinents, subcontinent of Eurasia ...

. Its common name is reference to the blackening of the plant's foliage as it dies. The seeds of the species are not to be confused with edible 'black peas', which are a form of ''

Pisum sativum The pea is most commonly the small spherical seed or the seed-pod of the flowering plant species ''Pisum sativum''. Each pod contains several peas, which can be green or yellow. Botanically, pea pods are fruit, since they contain seeds and d ...

''. Seeds of Lathyrus species are toxic, containing an enzyme that interferes with collagen synthesis to cause the disease

Lathyrism Lathyrism is a condition caused by eating certain legumes of the genus ''Lathyrus''. There are three types of lathyrism: ''neurolathyrism'', ''osteolathyrism'', and ''angiolathyrism'', all of which are incurable, differing in their symptoms and ...

Description

''Lathyrus niger'' is a perennial plant with erect, self-supporting stems that grow to . The stems are branched and unwinged and nearly hairless. The leaves are alternate with short winged stalks and narrow

stipule In botany, a stipule is an outgrowth typically borne on both sides (sometimes on just one side) of the base of a leafstalk (the petiole). Stipules are considered part of the anatomy of the leaf of a typical flowering plant, although in many speci ...

s. The leaf blades are pinnate with four to eight pairs of narrow elliptical leaflets with sharp tips, entire margins and no tendrils. The underside of the leaflets is bluish-green. The

inflorescence An inflorescence is a group or cluster of flowers arranged on a stem that is composed of a main branch or a complicated arrangement of branches. Morphologically, it is the modified part of the shoot of seed plants where flowers are formed o ...

s grow from the axils and are often one-sided. They have long stems with two to ten red flowers, each long, turning bluer as they age. Each flower has five sepals and five petals and are irregular. The uppermost petal is known as the "standard", the lateral two as the "wings" and the lowest two are joined to form the "keel". There are ten stamens and a single carpel. The fruit is a long black pod containing up to eight seeds. This plant flowers in June and July.

Distribution and habitat

''Lathyrus niger'' is native to Europe and parts of Asia. Its typical habitat is broad-leaved woodland, forest margins, woodland clearings and plantations.

Ecology

The flowers of ''Lathyrus niger'' are pollinated by bees and smaller insects are unable to make their way to the nectar source. The young flowers are red and visited by bees but when they have been pollinated they turn blue and stop producing nectar so the bees go elsewhere. The plant becomes black as the foliage withers at the end of the growing season.

References

niger ) , official_languages = , languages_type = National languagesFlora of Europe Flora of Serbia {{fabeae-stub