Two Trebouxia algae with different physiological performances are ever-present in lichen thalli of Ramalina farinacea. Coexistence versus Competition?, Leonardo M. Casano, Eva M. del Campo, Francisco J. García-Breijo, José Reig-Armiñana, Francisco Gasulla, Alicia del Hoyo, Alfredo Guéra1, and Eva Barreno, Environmental Microbiology (2011) 13(3), [1]