Gaura doesn't look much like an evening primrose, does it? That's probably why it has for a long time been in it's own genus, Gaura. Recent studies have shown that it should probaly be included in Oenothera, with the evening primrose. For that matter, this species isn't particularly scarlet. Gauras (often called beeblossoms) and evening primroses often share the habit of opening at night, and fading early in the daylight. Many also turn pink or even scarlet as they fade. Scarlet has been reported from AZ, CA, CO, IA, ID, IL, IN, KS, LA, MI, MN, MO, MT, ND, NE, NM, NV, NY, OK, SD, TX, UT, WA, WI, WY, AB, BC, MB, ON, and SK. Lake CO CO, 6/20/13.