Astrochapsa elongata

Astrochapsa elongata features a corticolous thallus that can grow up to 5 cm (2 in) in diameter and 30–60 μm thick. Its surface is smooth to uneven, cracked, whitish-grey, and slightly glossy. The photobiont associated with this lichen is Trentepohlia, and a medulla is absent. Apothecia are erumpent, angular-rounded to mostly elongate, measuring 3.0–7.0 by 1.5–3.0 mm, and can be simple or sometimes branched. The disc is partly to completely exposed and covered by thick white pruina. Ascospores are submuriform with 15–25 transverse septa and 0–1 longitudinal septum per segment, measuring 40–65 by 10–13 μm. No pycnidia have been observed.^[2]

Astrochapsa elongata is very similar to Astrochapsa recurva, but it can be differentiated by its narrower ascospores and the absence of secondary metabolites. Other similar species include Astrochapsa zahlbruckneri, Chapsa cinchonarum, and Pseudochapsa dilatata, which can be distinguished by their ascospore characteristics.^[2]

Astrochapsa elongata has been found on the trunk of Rhododendron simsii in northeastern Thailand, specifically in the lower montane scrub. At the time of publication, it was only known to occur at its type locality.^[2]