Arisarum vulgare, common name the friar's cowl or larus, is an herbaceous, perennial, rhizomatous plant in the genus Arisarum belonging to the family Araceae.
Arisarum vulgare reaches on average of height. The leaves of this geophyte plant are basal only, wide, ovate to arrow-shaped, with a petiole long. The stems are erect and unbranched, usually mottled and grow directly from the underground rhizome. A single leaflike bract (spathe) forms a purplish-brown or olive green striped tube about 5 inches long, with an open upper part helmet or hood-shaped curved forward. It encloses a fleshy greenish clublike spike (spadix) bent forward, protruding from the tube and bearing at the bottom minute purple violet flowers. The 20 male flowers are located above the four to six female, with sterile flowers completely missing. The flowering period extends from October through May. The sexes are united in the same individual plant. Pollination is granted by insects (entomophily). The fruits are greenish berries of about long.
Arisarum vulgare is native to the Mediterranean Basin, from the Caucasus in the east to the southeastern Iberian Peninsula in the west, where it introgresses with Arisarum simorrhinum.
Arisarum vulgare prefers grassy fields and rocky scrubland, forests and wasteland, mainly in shady and cool places and in moist soils, at an altitude of above sea level.
The main described subspecies are the following:
In Arisarum vulgare subsp. simorrhinum the flower stem is much shorter than the petioles. Bract and spadix are erect. The latter is thickened at the tip.