Lathyrus nissolia, the grass vetchling, is a species of flowering plant in the pea and bean family Fabaceae.

[1][2] Its common name refers to the grass-like foliage; an older alternative name is grass pea.

[3] Grass vetchling is an annual plant, with an erect stem branching from the base, and growing to a height of up to 90 cm.

The leaf stalk, however, is flattened out until it closely resembles a blade of grass up to 15 cm long and ending in a fine point, and the stipules at its base greatly help the deception.

[3] The flowers are succeeded by long, slender, straight pods, which are at first very flat, but become cylindrical when the contained peas are fully developed.