I was in a hurry in a search, hit an incorrect site and thought perhaps something had changed (so much has) since I learned plant families. Lumping and sorting. Malvaceae always did have 5 petals. Evening Primrose, four petals. Duh. So, mallow is very common in the desert areas, (many lovely orange flowers) but so is the evening primrose, lots of it around here as wildflowers.

Now I'll go back and read what Penny said. And if I can reproduce that search I'll send the site owner a note.

SRS