Opegrapha varia (Plate 28 from Albert Schneider's A text-book of general lichenology)

Explanation of the plate: 1. Lichen in situ. 2 (below 1). A small portion magnified and showing five elongate apothecia (or lirellae). 2 (to right of 1) A section through an apothecium, thallus and substrate. 3. Section through apothecium. 4. Section through the very flimsy thallus, with the filamentous hyphae and the darker, rounded cells of the photobiont. 5. Ascus and three paraphyses. 6. Spores. 7. Algae and hyphae.

Albert Schneider's A text-book of general lichenology, published in Binghamton in 1897 by Willard N. Clute & Co. illustrates the structural features of various lichens from the north-eastern United States.