Description:—Life form lichenized fungus. Thallus endoperidermal to epiperidermal, thin, effuse; surface whitish or greenish gray, in older specimens pale tan, smooth, occasionally with reddish or orange pigment crystals and areas of pinkish staining; prothallus brown, often as contact lines. Photobiont trentepohlioid alga, endoperidermal; cells (7.8–) 11.7 (–18.2) × (5.2–) 8.3 (–15.6) µm (n = 39), in short branched chains. Ascomata dispersed, sessile, elongate to furcate, lirellate with ±straight branches and acute tips, (0.4–) 1.0 (–1.6) × (0.2–) 0.3 (–0.5) mm (n = 60); disk flat, brown, often covered with whitish pruina; margin thick, coated with red or orange pruina.

In section ascoma (104–) 139 (–208) µm high (n = 6). Excipuloid layer lateral, (26–) 56 (–130) µm (n = 12) wide, dark brownish and infused with reddish pigment crystals. Epithecium (13–) 21 (–26) µm (n = 8) thick, brownish; hymenium hyaline, yellowish in thick sections, (52–) 64 (–91) µm high (n = 10); hypothecium pale brownish, (22–) 42 (–104) µm thick (n = 8). Asci abundant, clavate, (39.0–) 53.3 (–78.0) × (10.5–) 17.0 (–34.0) µm (n = 60), 8-spored, stipe short or indistinct, tholus (4.0–) 8.5 (–15.0) µm thick (n = 10); ascospores narrowly obovate, hyaline, smooth, faintly verrucose and appearing grayish and granular when postmature, macrocephalic, (4–)5-celled, (15.5–) 22.0 (–26.0) × (4.0–) 5.5 (–8.0) µm (n = 60). Pycnidia frequent, ±globose, partly immersed, (52–) 80 (–140) µm in diameter (n = 9), wall brown; conidia bacilliform, mostly straight, hyaline, (4–) 6.4 (–9) × ~1 µm (n = 10).

Chemistry:—Thallus UV–, K–, C–, KC–, PD+ golden yellow (psoromic acid); excipular pigment K+ magenta then fading; epithecium pigment dissolving in K. Amyloidity: epithecium I+ blue, K/I+ dark blue; hymenium I+ blue or turning red, K/I+ dark blue or green in high concentrations; ascus protoplasm I–, K/I+ yellow-orange; ascus wall I–, K/I–. A hemiamyloid ring in the tholus of the asci not seen.

Substrate, ecology and distribution:—Found on woody palm frond bases in coastal, subtropical environments in southeastern North America (Florida to North Carolina) and the Caribbean (Bahamas).