ok.....it looks like creeping charlie; but leaf structure looks different....keep it away from your tortoise. Its an invasive weed that would love to swallow up my lawn. I have uploaded a picture of creeping charlie in Iowa. it will get entangled with other weeds and grass; making recognizing them by leaf structure difficult It has the same color of some of the wild violets;which are safe; and I have to keep a close eye on him to kept away from the creeping charlie.