• Who: Calhoun's green thumbs and knack for writing earned him the 2006 American Horticultural Society Book of the Year nod for his work "Yard Full of Sun" and a 2008 Garden Writers Association Media Award for "Chasing Wildflowers." "The Gardener's Guide to Cactus; The 100 Best Paddles, Barrels, Columns, and Globes," is his most recent book.
• Where: "Plants in First Person: Lively Garden Memoirs" 1-2 p.m. Saturday in the Student Union Memorial Center Tucson Room; and "Sexy Southwest Succulents" 1-2 p.m. Sunday in Room 130 of the Integrated Learning Center.
• Who: Barr is a mystery writer who published her first novel in 1983. Many of her books take place in national parks and feature the protagonist, Park Ranger Anna Pigeon.
• Where: "The Doyennes of Southwest Mysteries" 2:30-3:30 p.m. Saturday in the Student Union South Ballroom; and "A Conversation with Nevada Barr" 10-11 a.m. Sunday in the Western National Parks Association: National Parks Pavilion.
• Who: Broyles is one three contributors to the book "Last Water on the Devil's Highway: A Cultural and Natural History of Tinajas Altas" who will speak at the Lawrence Clark Powell Memorial Lecture. The lecture series focuses on literary figures whose works reflect the region. Broyles will be joined by Gayle Harrison Hartmann and Thomas E. Sheridan.
• Where: Lawrence Clark Powell Memorial Lecture, 2:30-3:30 p.m. Sunday in the Student Union Gallagher Theater.
• Who: A research associate at the Southwest Center of the University of Arizona, McNamee has written and edited more than 35 books, including "The Only One Living to Tell: The Autobiography of a Yavapai Indian."
• Where: "Rim Stories: A Look at Who and How We Tell Stories" 11:30 a.m.-12:30 p.m. Saturday in the Student Union Ventana Room.
• Who: Irish is based out of the Phoenix area and has written several books on Southwest gardening, including "A Place All Our Own" and "Gardening in the Desert."
• Where: "Plants for Gardens, Food for Thought," 11:30 a.m.-12:30 p.m. Saturday in the Student Union Tucson Room; and "Plants in First Person: Lively Garden Memoirs," 1-2 p.m. Saturday also in the Tucson Room.