Peas with Odd Leaves

Caterpillar-plant Annual Scorpion-vetch Caterpillar-plant Yellow Vetchling

What are they?

Members of the pea family are readily told by their distinctive flowers, but they are a very diverse group when it comes to their leaves and other features such as fruits. Most species have pinnate or trifoliate leaves, but the species here are unusual in having rather different leaves. Some have leaves made up of a single blade, but which may look trifoliate due to enlarged stipules at the base of the leaf stalk. In some instances, the leaves may even become reduced to simply tendrils, in which case, the enlarged stipules function as leaves in photosynthesising. This group of plants consists of species that are mostly short annuals.

Where are they found?

The majority of these plants are uncommon, largely introduced species, so may typically be found in man-made or seminatural environments such as gardens, urban areas, rough ground and other disturbed locations.

Identification

Most species can readily be identified by a combination of flower colour and leaf shape.



Culinary Pea      Pisum sativum

Introduced as a vegetable from mainland Europe and widely grown as a field crop. Occasional plants may appear on roadsides or field edges from spilt seed. Flowers July to August. An annual plant with unwinged stems and with remarkably adapted leaves. The leaf itself is reduced to merely a many-branched tendril with no blades, while the role of the leaf has been taken over by the greatly enlarged stipules that sit in pairs alongside the main stem. The flowers of cultivated plants are typically white with green veins, but flowers from wild stock are typically lilac and purple.

Culinary Pea Culinary Pea Culinary Pea Culinary Pea
Habit
Flower
Flower
Leaves


Yellow Vetchling      Lathyrus aphaca

Occurs both as a rare native of chalky grass banks or on the Suffolk boulder clay, or as an introduction from southern Europe. Flowers July to August. A small annual plant with leaves reduced simply to tendrils. However, the leaf stipules are much enlarged and create the impression of spear-shaped leaves, pressed against the main stem. The flowers are typically bright yellow on native plants, but introduced plants may have cream-coloured flowers.

Yellow Vetchling
Habit


Winged Vetchling      Lathyrus ochrus

Introduced from southern Europe. A rare annual species that has been reported from Cambridgeshire Flowers July to August. A small annual with rather peculiar leaves. The midrib and stalk of the leaf is broadened out into a flat blade. The leaf then has a single pair of opposite leaflets toward the top of the leaf, accompanied by a terminal tendril. The flowers are very pale, creamy-yellow in colour.

Winged Vetchling Winged Vetchling Winged Vetchling
Habit
Flowers
Leaf


Annual Scorpion-vetch      Coronilla scorpioides

Introduced from southern Europe. A rare, casual plant, recorded in the region less than five times. Flowers July to August. A small annual plant with simple, ovate leaves, the leaves having enlarged stipules that create the impression of a trifoliate leaf. Small yellow flowers are followed by segmented seed pods that have a 'scorpion-tail' tip to them.

Annual Scorpion-vetch
Leaves & Seed pods


Caterpillar-plant      Scorpiurus muricatus

Introduced from southern Europe. A rare, casual plant, recorded in the region less than five times. Flowers July to August. A small annual plant with simple, ovate leaves, the leaves having narrow, pointed stipules. The flowers are followed by twisted and coiled, spiny seed pods that fancifully look somewhat like little caterpillars.

Caterpillar-plant Caterpillar-plant
Habit
Flowers