The evening primroses (Oenothera speciosa) are in bloom and they are quite lovely. They have spread through the garden but I wouldn’t call them an aggressive species, we don’t mind. We can easily pull them up if they show up where they aren’t wanted and generally, our garden isn’t so well organized that it matters. They are native to the southern half of the contiguous United States. They make a nice addition to any garden, blooming in the evening, their airy, pink blossoms particularly lovely in the dusk.