Whether it is grown intentionally, or considered to be a common roadside weed, there is no denying that perennial pea, Lathyrus latifolius, knows how to brighten some of the wilder parts of the garden with brilliant purplish pink bloom. Some garden varieties bloom either pale pink or white, just like a few random feral plants do. Bloom resembles that of sweet pea, but without fragrance.
By their second year, the potentially six foot long vines might be a bit too rampant for more refined situations. They happen to work nicely to climb over wood piles and otherwise unsightly chain link fences though, even if only temporarily until they die back to their fat subterranean taproots by the end of summer. They will be gone before the firewood they conceal becomes useful again.
New bluish green growth regenerates vigorously at the end of winter, but does not bloom until early summer. The compound leaves are comprised of only a single pair of narrowly oblong leaflets with a branched tendril in between. Each leaflet is about two inches long and less than half as wide. Stems and petioles are winged. Once established, perennial pea can be difficult to eradicate.