Nylander called the apothecium pale within, but forms with red-brown hypothecia are admitted by later writers.
"Ohio Biological Survey, Bull. 10, Vol. 11, No. 6" by Bruce Fink and Leafy J. Corrington
Piece of thallus of Parmelia conspersa, with section through an apothecium.
"The Elements of Botany" by Asa Gray
In the Helvellaceae there is no apothecium but a large irregular fruit body which at maturity bears the asci on its surface.
"Encyclopaedia Britannica, 11th Edition, Volume 11, Slice 3" by Various