"A greatly magnified view of a perpendicular section of Parmelia aipolia, showing the thecae in the shield, a; b, the hypothecium and some gonidia beneath it; c, the medullary region; and d, the gonimic layer." -Lindley, 1853

Leaf Lichen

"A greatly magnified view of a perpendicular section of Parmelia aipolia, showing the thecae in the…