Nash, T.H., Ryan, B.D., Gries, C., Bungartz, F., (eds.) 2004. Lichen Flora of the Greater Sonoran Desert Region. Vol 2.
Pseudothecia: black immersed, 0.13-0.22 mm in diam. ascomatal wall: apically dark brown, thickened, below brown to reddish brown paraphysoids: absent periphyses: septate, branched or not, 12-18 x (1.5-)2.5 µm asci: cylindrical to slightly clavate, sessile or with a short stalk, (40-)50-60(-77) x (12-)15-20(-24) µm, 8-spored ascospores: pale to medium brown, septate, not or distinctly constricted at septum, narrowly ellipsoid, often curved, 16.5-19.5 x 5.5-7 µm; wall: thin and mostly smooth Pycnidia: not seen. Hosts: on the thallus of Rhizocarpon species World distribution: Africa, Asia, Australia, Europe, and North America Sonoran distribution: One location in eastern Arizona. Notes: Endococcus macrosporus was treated by Triebel (1989) as a synonym of E. perpusillus Nyl. using a wider species concept. But using a narrower species concept of Sérusiaux et al. (1999), the taxon on Schaereria tenebrosa has to be named E. perpusillus, whilst E. macrosporus is used for specimens growing on Rhizocarpon with immersed, 0.13-0.22 mm large pseudothecia and 16.5-19.5 x 5.5-7 µm large ascospores.