About Lathyrus latifolius L.
Morphologically, Lathyrus latifolius has winged, hairless stems, and alternate blue-green compound leaves. Each leaf is made up of one pair of leaflets and a winged petiole that is about 2 inches (51 mm) long. The leaflets are narrowly ovate or oblong-ovate, with smooth margins and no hairs, and can grow up to 3 inches (76 mm) long and 1 inch (25 mm) across. A branched tendril sits between the two leaflets of each compound leaf. Lathyrus latifolius can reproduce either vegetatively from its taproot and rhizomes, or by seed. It is a perennial herbaceous climbing vine that can reach 6 feet or more in length by twining around supports with its tendrils, and will sprawl across the ground in open areas. This species is frost-hardy, long-lived, and spreads slowly. By the end of summer, its foliage becomes quite ragged and turns yellowish. It grows best in partial to full sun, in loam or clay-loam soil that is moist, mesic, or slightly dry. Unlike the related annual sweet pea Lathyrus odoratus, which it is often confused with, Lathyrus latifolius has no floral scent. Though it is grown as a garden plant, it can become pervasive and hard to remove. For this reason, the species is often considered a weed, even though it has an attractive appearance. Numerous cultivars have been selected for garden use. The following cultivars have gained the Royal Horticultural Society's Award of Garden Merit: the pink species-type L. latifolius, white-flowered 'Albus', pale pink 'Rosa Perle', and white-flowered 'White Pearl'.
