alvenever

<p>Thallus foliose, occasionally reaching diameters of over a meter.  Lobes broad, rounded, 2-4 (-6) cm wide, with ascending margins.  Upper surface brown or light greenish when dry, becoming bright grass-green when wet.  Cephalodia scattered across upper surface, warty, grayish brown, 0.5-2 mm wide.  Lower surface whitish at margins, becoming black or dark brown at center, with tomentum, rhizines growing in fascicles.  Apothecia with a green cortex below, reddish- to blackish- brown disks (Brodo et al, 2001; McCune and Geiser, 1997; Thomson, 1950). <br />Anatomy:<br />Upper cortex 25-55 µm thick, pseudoparenchymatous, colorless to light brown; algal layer 25-35 µm thick, with cells 2.5-6 µm; cyanobiont cells in cephalodia 6-9 µm diameter; medulla 460-1350 µm (Thomson, 1950).  Apothecia 7-16 mm across (Brodo et al, 2001; Thomson, 1950); hypothecium brown; hymenium colorless to light brown, paraphyses undivided, tips red-brown.  Asci 80 x 12 µm, with 8 spores per ascus.  Ascospores  acicular, pluriseptate,  45-75 x 4-7 µm (Thomson, 1950). </p>