Some lichen observations posted to Mushroom Observer from Big Bend National Park, Texas.

For more trans-Pecos lichens, see the lichens of the Davis Mountains, Texas

A list of the lichens in the park can be generated at the Lichens of the US National Parks web site. In January, 2010, the park checklist included 289 species of lichens.

References:

Wetmore, Macrolichens of Big Bend National Park, Texas. The Bryologist, Vol. 79, No. 3 (Autumn, 1976), pp. 296-313

Wetmore, Lichens and Air Quality in Big Bend National Park, Texas, The Bryologist, Vol. 84, No. 3 (Autumn, 1981), pp. 426-433

Egan, New and Additional Lichen Records from Texas. II, The Bryologist, Vol. 80, No. 1 (Spring, 1977), pp. 136-142. Includes a key to the 17 species of Xanthoparmelia then known from Texas.

Carr, The Lichens of Texas [part 1] and [part 2], The Nature Conservancy of Texas. Undated, but this well-organized report includes references through 1978.

Bungartz, Rosentreter, Nash, Field Guide to Common Epiphytic Macrolichens in Arizona, ASU Lichen Herbarium. Excellent survey of southwestern epiphytic macrolichens.