Is that a species of concern in my mother's petunias?

It's a duskywing skipper, probably Propertius duskywing. Washington lists the species as vulnerable, and British Columbia lists it as a species of concern because it depends on Garry Oaks, a tree which is becoming scarce in British Columbia, largely because great chunks of its habitat have been swallowed up by towns and suburbs.
According to the references, these insects are most likely to show up in May, though flights in July have been known to happen.