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Family: Acarosporaceae
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MB#363916 TYPE: United States, Utah, Wayne, Ekker's Ranch, 1830 m, on dry sandstone, 5 19 1950, S. Flowers s.n. (UPS, holotype; ASU, ASUL000374, isotype). Description. Hypothallus in substrate. Thallus an areolate crust, covering areas up to 10 cm, expanding through replication by division, areoles 0.2–2 mm wide, up to 600 µm thick, broadly attached to substrate. It has a flat topography until areoles become mature and swell, varying in height. Upper surface epruinose or lightly pruinose, without or with fissures, whitish when dry, gray-brown when wet. Epicortex 20–60 µm thick. Upper cortex 40–60 µm thick, irregular cells to 5 µm wide, upper layer red brown, lower layer hyaline. Algal layer 70–100 µm thick, continuous, except under apothecium, cells mostly 10 µm wide. Medulla 200–300 µm thick, gray, filled with substrate crystals, hyphae obscured, intricate 2–5 µm wide. Ecology and Distribution. Acarospora utahensis is a poorly known species occurring in Utah and Colorado with unverified reports from Idaho, Arizona and New Mexico: The species so far has been found on both calciferous and non-calciferous sandstone. Discussion. This species is easily identified by the euamyloid hymenial gel, high hymenium (usually 120–170 µm tall), variable ascospores 3–5 (–9) × 1.5 (–4) µm, and the white color formed by the thick epicortex. It looks like a member of A. strigata group. Literature Magnusson, A. H. (1952). New crustaceous lichen species from North America. Acta Horti Gotoburgensis 19: 31–49. |