Sometimes called Perennial Sweet Pea. These weedy vines cover hillsides in residential neighborhoods, often where they had been planted generations before. Once you have Everlasting Peas, you have them forever. But is that such a bad thing?
From Gray’s Manual of Botany: L. latifolius L. (EVERLASTING or PERENNIAL PEA.) Tall perennial with broadly winged stems; leaves and stipules coriaceous and veiny; petioles mostly winged; the 2 elliptic to lanceolate leaflets 0.5-1 dm. long; peduncles stiff, many-flowered; flowers showy, pink, purple, or white. Frequently cultivated, and escaping to roadsides and thickets, Ct. to D. C. (Introd. from Eu.)
(This was from the 1908 edition. The 1890 edition does not list Lathyrus latifolius, suggesting that it had not yet become established as a frequent escape.)