What do a willow tree, a sunflower and a cactus have in common? They're all superheroes! Dig in to this book and discover how plants can save your life. Superhero Plants is at Oxford Reading Level 9. It is for readers aged 7 to 11 years old who are working below expected standard in their reading. The Readerful Rise series ensures that older struggling readers have books with age-appropriate content and topics, that look like the books their peers are enjoying, but are written at a level they can read successfully.