J. Bot. 76: 351 (1938) [and in Bull. Soc. Sci. Bretagne 16, Fasc. Hors Sér. 2: 71 (1939)].

Type locality: Cuba, in pinetis, C. Wright in Wright: Lich. Ins. Cubae 39 (PC-Hue - lectotype; FH, FH-Tuck, G, M, UPS, US - isolectotypes). Lectotypification by Ahti (1993: 76).

Thallus: whitish-grey, quite often the apical branchlets are somewhat yellowish (in herbaria at least). Data lacking.

Photobiont: Data lacking.

Chemistry: Perlatolic acid, atranorin (Asahina 1940) constant, usnic acid reported as accessory (Evans 1952), PD-, K+, K(Cl)-(or+?) Ahti (1961: 23).

Note: "C. evansii is a distinctive, independent species. From its closests relative, C. pseudevansii, it is distinguished by slight morphological and considerable distributional differences besides widely different chemical properties. C. evansii is a strictly lowland species with pronounced oceanic and subtropical tendencies, while C. pseudevansii is an oceanic species with subarctic-boreal and montane tendencies. Usnic acid is generally absent in C. evansii, but, according to Evans (1925), Asahina once, and later Evans himself in two cases, demonstrated the occurrence of usnic acid in in it. The specimens in question are of the yellowish form (f. icterica Des Abbayes 1939 p. 72). If these statements are valid, we may note that the occurrence of usnic acid as a typical accessory component, as it seems to be in this species, is an uncommon phenomenon. Wheter there exists a real usnic acid strain with a specific distribution, cannot be judged without further observations" (Ahti 1961: 23).