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Baeomyces placophyllus Ach.
Family: Baeomycetaceae
[Biatora placophylla (Ach.) Fr.,  more]
Baeomyces placophyllus image
Stephen Sharnoff  
Thompson, J., 1984. American Arctic Lichens: The Macrolichens.
Thallus forming rosettes, the center squamulose, the margins lobate foliose, the marginal lobes close to the substratum and raised only at the tips; main lobes to 5 mm broad, gray-green, when dry whitish or ochraceous, somewhat pruinose; the margins with pale whitish is-idia or papillae 0.2 mm wide, broadening into squamules; podetia large, to 6 mm tall and 2 mm broad, deeply fissured, naked or covered with squamules. Apothecia to 4 mm broad, one to a few per podetium; disk soon swollen, the margin often reflexed, light ochraceous brown to brownish red; cortex 10-20 μ thick, the hyphae more or less parallel to the surface, the algal layer glomerulate and the hyphae between the glomerules rising and fanning over the surface, the hyphae leptodermatous 2.5-3 μ diameter; hyphae of the podetium gelatinous, dense, 2.5-3 μ in diameter with numerous elongate interstices containing algae; hymenium 90-150 μ, I— ; paraphyses slender, simple or branched toward the tips; asci cylindrical, 90-130 X 6-8 μ; spores 8, fusiform, 1-celled, 8-14 x 2-4 μ. Conidia unknown.

Reactions: K+ yellow, P+ orange.

Contents: stictic acid.

This species grows on sand, clay soil, and raw humus. It is circumpolar in the boreal forest but has also been collected in Java. In North America it ranges from Newfoundland to Alaska and south to New Hampshire and Massachusetts.