Golubkova NS, Zhurbenko MP 1990: Acarospora putoranica Golubk. et Zhurb. lichen e parte media Sibiriae novus. Novitates Systematicae Plantarum non Vascularium [Academia Scientiarum URSS, Institutum Botanicum Nomine V. L. Komarovii] 27: 101-106.
Thallus squamulose, brown, sometimes olive-brown, the squamules crowded and in turn confluent. Clumps of subfruticose-squamulose lobes to 5 cm in diameter, 1.5-2 cm deep below the substrate, attached by and consisting of fasciculate rhizoids. Squamules 1.5-4 (6) mm in diam. Young squamules irregularly orbicular, becoming orbicular-lobate, sometimes undulate. Margins commonly clumped within the lobes, which are 4-5(8) mm long, 2.5-5 mm wide and extended, tightly compact. Squamules usually alternately imbricate, pale or dark olive-brown above, more or less shiny, rarely white-pruinose on both sides, smooth, plicate-rugose on both sides. Margin commonly slightly thick, darker, covered over, underneath black-brown to black, shiny, with fasciculate rhizoids. Fasciculate rhizoids 5-15 (20) mm long, 0.5-1.5 mm thick, robust, subfruticose-branched, brown, more or less terete or flat (upper part of the main parts of the branches). Central squamules frequently perpendicular or angled down slightly or originating in--in thallus periphery--angled marginal squamules, internally connate on both sides, and thalli commonly clumping to the center radially, crowded together and formed into a connate fungal shape.
Thallus heteromerous, 250-500 µm thick. Upper cortex 25-50 µm, thick; exterior brown, interior hyaline, paraplectenchymatus, the cells more or less subglobose: 6-8 X 5 µm. The layer amorphous, thin, with unequally thick roof. Algal layer ca. 75 µm thick, continuous, lower part undulate. Lower cortex ca. 15 µm thick, paraplectanchymatous.
Apothecia (0.8) 1.3-3.5 mm in diameter, 1-3(6) per squamule. Sometimes confluent, dark-brown to blackish, glabrous, before death cryptolecanorine, immersed in thallus. Disc plane and smooth, emarginate, rarely lecanorine to broad, sitting in thallus. Disc barely or greatly convex, surrounded by concolourous with thallus thalline margin. Excipulum 14-28 µm thick, hyaline, located towards hymenium margin. Hypothecium 100-330 µm thick, hyaline, more or less paraplectenchymatous. Hymenium 130-140 µm tall. Epithecium dark reddish-brown, 10-12 µm thick. Paraphyses 2-2.5 µm thick, simple, distinctly septate, apiculus clavate, brown, 4-5 µm in diam., terminated, upper part conglutinate by gelatin. Asci 100 X 20-38 µm, clavate. Spores 7.5-11 (12) X 5-7.5 µm, broadly elliptical, numerous in ascus. Pycnidia numerous, quite conspicuous on the surface of squamules, dark-verruculose, ca. 250 µm in diameter, more or less orbicular, sterigmata unbranched. Pycnoconidia 2.5 X 1 µm, baciliform.
Cortex and medulla K-, P-, C-, KC-, I-. Hymenium I+ blue. Thallus contains traces of gyrophoric acid (Fig. 1-3).
Relationship. A. putoranica belongs to subsect. Macrosporae Magn. (Magnusson, 1929) and A. macrosporae (Hepp) Bagl. so that apparently it is extremely akin to that species from which it differs in thallus structure; robust, fasciculate rhizoids; large apothecia; and convex, black-colored disc always surrounded by thallus margin. Trending towards a large thallus is a particular, very distinguished feature, and the robust, fasciculate rhizoids of A. putoranica allow it to occupy a singular location in the general system. The fasciculate rhizoids of the species are similar to A. reagenti Zahlbr.—lichen epigeal, only observed in the desert.