Lynge B. 1940. Lichens from Northeast Greenland collected on the Norwegian Scientific Expeditions in 1929 and 1930 II. Microlichens. Skrifter om Svalbard og Ishavet 81: 1-143.
Kapp Petersens, on drift wood of Populus (det. Dr. Elias Mork).
Thallus completely invisible.
Apothecia small, diam. 0.3-0.6 mm, numerous, but dispersed, from initially immersed in wood, then more elevated and base constricted, but not stipitate. Disc epruinose, black, nevertheless when wetted trending towards grayish-brown/blackish-brown, initially plane and margin thin or somewhat thin, entire or subcrenulate, often pruinose, encircling [disc], then convex, immarginate. Excipulum arachnoid (thin section), gonidia abundant. Excipulum in inferior part cortex thick, 35-40 µ tall, hyaline, provided with perpendicular hyphae, in itself margin subecorticate. Interior part of hypothecium surface formed from parallel hyphae p.m. , in upper exterior part, hyphae entirely straight. Hymenium narrow, 45-50 µ tall, covered by thin amorphous layer, epithecium entirely egranulose, dark/grayish-brown/blackish-brown, except for hyaline hymenium. Paraphyses conglutinate in water, robust, c. 2 µ thick, dark-capitate, upwards 4-5 µ thick. Paraphyses unchanged in HCl, and also sparingly changed in KOH, if not, easily separated, apparently branched on both sides. Asci fertile, not numerous, narrowly pyriform, spores 8, ellipsoid or oblong, 11-12.5 X 4-5 µ.—Pycnidia not seen.
Hymenium I red, excipulum I yellow, but not blue. Medulla KOH not imbued.
The negative reaction of the medulla by KOH will distinguish the species from the Lecanora subfusca section. There are then 2 papers, that should be consulted for the identification of our species, the first of which is Vainio Lich. Pitlek., 1909. In our species there is a distinct chondroid cortex on the under side of the excipulum, but several sections clearly show that it is missing along the margin. This will exclude Lecanora Behringii Nyl.
The saxicolous Lecanora Nordenskioldii Vain. has a “thallus crustaceus”, larger apothecia (0.4-1.2 mm), and a higher hymenium (80 µ). The lignicolous Lecanora Palanderi Vain. has still larger apothecia (0.6-1.6 mm), its disc is “lividorufescens, tenuiter pruinosus”, its paraphyses “tenues aut sat tenues (1-1.5 µ)”, it also has a “thallus crustaceus”. Its cortex agrees with our plants. On the whole it is difficult to exclude it with full certaintly, but the agreement does not seem convincive. I have at present no access to the type plant. The saxicolous Lecanora glaucoatra Vain. has a verrucose thallus and must be another species.
The other paper is Hedlund’s “Kritische Bemerkungen” from 1892. The epithecium of our species is not in the least granular, which must exclude this species, p. 36-49.
Hedlund’s Lecanora symmictiza (Nyl.) Hedl. has a brown disc, and Herb. Lich. Fenn. No. 163 differs sufficiently from our plants. They more resemble Lecanora hypoptoides Nyl., as seen in Herb. Lich. Fenn. No. 126. But in the last mentioned plant the apothecia are smaller than in ours, rarely surpassing 0.4 mm, they are also more appressed, and very inconspicuous. It also differs in its cortex: “superne non attenuates”, and in the reaction of its excipulum: “pars central excipuli J caerulescens”.
Our plants might be compared with Lecanora obscurella (Somrft.) Hedl. which differs in its small apothecia, rarely exceeding 0.4 mm in diam., its brown disc (moistened), its very thin and easily discrete parphyses, and in the same reaction of the excipulum by J as in Lec. hypoptoides. The type plant is “Lecidea pellucida v. obscurella” in Somrft. Plantae cryptogamae Norvegiae, No. 132, it is truly a Lecanora, as is seen by its excipulum, in agreement with Hedlund’s statement.
I have named it surrecta, “raised from the sea”.It is doubtful whether an exobiont can be transported by drift wood over such great distances.But it might be possible for an endobiont, such as the present species.The substratum, Populus, and the direction of the arctic streams, suggest a very long drift, perhaps from the forest zone of a Siberian river.