Emma Watson's 'Wallflower' adds Mae Whitman

Parenthood actress Mae Whitman will join Emma Watson in the cast of The Perks of Being a Wallflower, reports Variety.

The movie centres on Charlie (Percy Jackson's Logan Lerman), a 15-year-old outsider struggling through life and dealing with his feelings for Watson's character.

Whitman, who recently appeared in Scott Pilgrim Vs. The World, will play a tattooed vegetarian who is Charlie's first girlfriend.

Wallflower will be written and directed by Stephen Chbosky, based on his 1999 novel of the same name. Filming is due to start next month in Pittsburgh.

Watson will star as Hermione Granger for the final time in this summer's Harry Potter and the Deathly Hallows: Part 2. She also has a supporting role in Michelle Williams's upcoming Marilyn Monroe biopic My Week with Marilyn.