It looks like a purple version of Hibiscus
Yes, like Yvonne mentioned (before we got sidetracked on tortoise pickiness) it's a Rose of Sharon, which is a type of hibiscus. Easy to grow, if you've got a lot of tortoises to feed!
I could find some red variety of Hibiscus over here. Do you think it is ok to pluck at night? The flowers are closed up at night though
Ok thank you!I think it doesn't matter when you pluck it, as long as it doesn't have pesticides. Your tortoise will love the flowers open or closed. Red is their favorite color!