* Buellia eganii Bungartz, in Bungartz & Nash (2004: 445).

Characterized by the thick, areolate to rimose-areolate, pale greyish thallus containing lecanoric acid (C+ red), the non-amyloid medulla (I-), the immersed apothecia with a brown (N-) proper exciple and epihymenium and a hyaline hypothecium and the Buellia - type ascospores, 11.0–17.0 × 7.0–8.0(–9.0) µm with microrugulate spore walls (visible at × 1000). This silicolous species occurs in subalpine to alpine habitats and was hitherto known only from Arizona and New Mexico (Bungartz & Nash 2004).

Material examined: ― GUATEMALA. (A) Quezaltenango: NW of Quezaltenango, NNW of San Marcos, along trail from San Sebastian to top of volcano Tajumulco, on ENE slope, above the small village El Rodeo, shrubs and outcrops in open field, on sloping volcanic rock, 3150 m, 15° 2.9' N, 91° 51.3' W, 25 July 2004, P. & B. van den Boom 33043, 33049, 33079 (hb. v.d. Boom) .