Umbilicaria rhizinata Krzewicka 2010

• Main Author: Davydov, Evgeny A.
• Format: Other/Unknown Material
• Language: unknown
• Published: 2022
• Subjects: Biodiversity; Taxonomy; Fungi; Ascomycota; Lecanoromycetes; Umbilicariales; Umbilicariaceae; Umbilicaria; Umbilicaria rhizinata; Baffin Island; Canada; Hale; Baffin
• Online Access: https://zenodo.org/record/6302389; https://doi.org/10.5281/zenodo.6302389

Umbilicaria rhizinata (Frey & Poelt) Krzewicka (2010: 491) Mycobank no. 548351 Umbilicaria decussata (Vill.) Zahlbr. var. rhizinata Frey & Poelt (Poelt 1977: 419). Type:— NEPAL. Mahalangur: Himal Khumbu, Moränen des Lobuche-Gletschers bei Lobuche, elev. 4950–5000 m, September 1962, J. Poelt L247a (lectotype M–0035585!; isolectotype M–0035586!). Umbilicaria aprina Nyl. var. halei Llano (1956: 183), syn. nov. Type:— CANADA. N.W.T.: Baffin Island, head of Clyde Fiord, on exposed gneiss boulders, 26 August 1950, M. E. Hale 450 (holotype MIN–664956!, Fig. 1). The holotype specimen of U. aprina var. halei has a similar morphology to the Himalayan U. rhizinata: small size, dark grey granulate upper surface, lower surface covered with black patches of thalloconidia in the central part only, and scarce dichotomous pale rhizinomorphs (Fig. 1). Thalloconidia are sphaerical to ellipsoid, brown to dark brown 3- or 4-celled when mature, but often also 2- or rarely 1-celled (Fig. 2). The sizes were (12.6–)15.0–16.2–17.5(–18.7) × (10.7–)12.6–13.7–14.9(–16.5) μm for (3-)4-celled (n=25), (11.6–)12.8–13.7–14.9(–16.5) × (8.0–)8.7–9.7–10.7(–11.7) μm for 2-celled (n=25), and (8.1–)9.3–10.3–11.4(–12.0) × (7.6–)8.5–9.5–10.6(–11.4) μm for 1-celled thalloconidia (n=25). The wall was 1.3–1.8(2.8) μm. The average size for all types of thalloconidia is 10.9–13.6–16.4 × 8.8–11.0– 13.2 μm which agrees well with the data presented by Krzewicka (2010) for U. rhizinata. All the remaining characters of U. aprina var. halei also perfectly fit the circumscription of U. rhizinata, except, none of the three specimens of the U. aprina var. halei holotype has a distinct reticulate pattern at the centre. They are coarsely pruinose with crystals positioned centrally near the umbo, but lack a reticulate pattern. Additionally, examined specimens from the Altai Mts. are only occasionally reticulate at the centre. This can be explained by the smaller size of both the holotype and the Altaian specimens (0.8–1.3 cm v. 1–2(–3) cm of U. rhizinata). As ...