Such grains are referred to as monocolpate.
Examples are common in the lily family, the palms, and numerous others.
Ephedra is a bushy coniferous desert plant with bristly stems and diminutive leaves. It is the source of a powerful drug, ephedrine, used in antihistamines. Monocolpate grains are occasionally encountered in the Paleozoic, but are common beginning in the Triassic and range to Recent in the fossil record.