Rinodina jacutica Galanina & Konoreva, 2022

Galanina, Irina A., Sheard, John W. & Konoreva, Liudmila A., 2022, A new saxicolous species, Rinodina jacutica (Physciaceae, lichenized Ascomycota) from the Republic of Sakha (Yakutia), Russia, Phytotaxa 564 (1), pp. 121-126 : 122-124

Rinodina jacutica Galanina & Konoreva sp. nov. Mycobank no: 841873

( Figs 1A–C )

Thallus thin to thick, areoles at first discrete, becoming confluent, light gray with a slight yellowish tinge. Apothecia quickly become narrowly attached. Vegetative propagules absent. Ascospores Dirinaria - type, (16.5–) 18.0–20.0 (– 23.0) × (7.5–) 8.5–10.0 (–11.5) μm, lumina Physcia- like, spores lightly pigmented at maturity, most mature spores inflated at septum, more so on application of KOH; torus absent; walls lightly ornamented. Secondary metabolite atranorin by TLC.

Type:— RUSSIA, Republic of Sakha, Oymyakonskiy District , near Ust-Nera , right bank of Ambar-Yuryuete , Larix gmelinii - Sphagnum -lichen forest, 64°30′31.6″N, 143°16′56.8″E, 1179 m a. s. l., 7 July 2016, L. A. Konoreva 75 (holotype LE 15578 !, isotype VLA L –2928!) .

Thallus thin in young parts to thick (0.4 mm) in old parts, light gray with a slight yellowish tinge, areolate, margin of scattered areoles. Areoles 0.2–0.5 mm wide, at first discrete, margins even or dissected and sublobate, then confluent, surface, matt, slightly convex. Prothallus black, well developed, clearly visible between areoles in young parts of the thallus ( Fig. 1A ). Vegetative propagules absent. Apothecia numerous, broadly attached when young but quickly become narrowly attached, scattered when young and densely contiguous in older parts of the thallus, 0.9–1.0 (–1.5) mm diameter (n = 30); disc black, at first plane, becoming slightly convex; thalline margin concolorous with thallus, mostly continuous but sometimes with a crenulate (beaded) appearance, to 0.1 mm wide, persistent, excipular ring absent. Сortex of apothecia to 20–30 μm wide with a slight yellowish tinge, not expanded below, epinecral layer absent, algal cells to 8.5–12 μm long. Proper exciple hyaline, 15 μm wide, expanding to 20 μm at surface, pigmented the same colour as epihymenium; hypothecium hyaline, 30–90 μm high; hymenium 80–150 μm high, paraphyses 1.5– 2.0 μm wide, not conglutinate, apices to 5.5–6.0 μm wide, forming a dark brown epihymenium, pigment arnoldiana - brown. Ascospores 8 per ascus, type A development, Dirinaria - type ( Fig. 1 : B, C; 2: A, B), (17.0–) 18.3–20.4 (–23.0) × (7.8–) 8.4–9.5 (–11.0) μm (n = 60), torus lacking, septal disc sometimes present ( Figs. 1C , 2B 4), walls lightly ornamented.

Chemistry: cortex K+ yellow, P+yellow (atranorin confirmed by TLC on 3 July 2021 by Paukov; and on 19 January 2022 by Konoreva).

Etymology: The species is named after the site of its discovery, Yakutia, the cold pole of the northern hemisphere.

Ecology: On stones in coniferous moss-lichen larch forest of the Ambar-Yuryuete river valley.

Notes: The species was found in the Oymyakonsky Region, located in the eastern part of the Republic of Sakha (previously Yakutia) on the border with the Magadan Region and the Khabarovsk Territory. The Tas-Kystabyt Ridge (highest point 2341 m) is located within this region. The climate of the Oymyakonsky Region is very continental, the annual temperature range spans 100 °C (minimum -65 °C, maximum 35 °C). The region is extremely dry, the annual precipitation being around 200 mm. The region is in an area of continuous permafrost ( Danilova, 2005). Larch woodlands occur at altitudes of 600(–800) m to 1200(–1600) m above sea level. At higher altitudes larch forests are replaced by thickets of dwarf pine, and mountain tundras are located at the highest elevations ( Karavaev & Dobretsova, 1964; Danilova, 2005).

Additional specimen examined (paratype). RUSSIA, Republic of Sakha, Oymyakonskiy District, near Ust-Nera , right bank of Ambar-Yuryuete , Larix gmelinii - Sphagnum -lichen forest, 64°30′31.6″N, 143°16′56.8″E, 1179 m a. s. l., 7 July 2016, L. A . Konoreva 65 (paratype LE 15579 !) .

Figures

FIGURE 1. Rinodina jacutica. A. Habit of Rinodina jacutica, scale bar = 1 mm. B–C. Dirinaria-type spores of Rinodina jacutica. B. Spores within ascus, note the Physcia-like lumina and lack of a torus. C. Spore structure, note the septal swelling, the lack of a torus and presence of a septal disc. Scale bar for spores = 10 μm.

FIGURE 2.Spore ontogeny of Rinodina jacutica: A 1–6.Early spore development prior to wall pigmentation;1, 2. apical walls unthickened prior to septum formation – type A development; 3, 4. septum present and walls equally thickened; 5, 6, walls thickened at apices and septum - Physcia-like locules. B. 1–5. Mature spores, walls pigmented, torus not evident, apical and septal wall thickening; 1, 2. locules Physcia-like; 3-5. spores with swelling at the septum; 4. spore focused to show septal disc, a characteristic of the Dirinaria-type spore. Scale bars = 10 μm.