C. Campylidium and Orthidium
Müller[696] has described under the name Campylidium a supposed new type of asexual fructification which he found on the thallus of tropical species of Gyalecta, Lopadium, etc., and which he considered analogous to pycnidia and spermogonia. Wainio[697] has however recognized the cup-like structure as a fungus, Cyphella aeruginascens Karst., which grows on the bark of trees and occasionally is parasitic on the crustaceous thallus of lichens. Wainio has also identified the plant, Lecidea irregularis, first described by Fée[698], as also synonymous with the fungus.
Another name Orthidium was proposed by Müller[699] for a type of fructification he found in Brazil which he contrasts or associates with Campylidium. It has an open marginate disc with sporophores bearing acrogenous spores. He found it growing in connection with a thin lichen thallus on leaves and considered it to be a form of lichen reproduction. Possibly Orthidium is also a Cyphella.
III. SPERMOGONIA OR PYCNIDIA
A. Historical Account of Spermogonia
The name spermogonium was given by Tulasne[700] to the “punctiform conceptacles” that are so plentifully produced on many lichen thalli, on the assumption that they were the male organs of the plant, and that the spore-like bodies borne in them were non-motile male cells or spermatia.
The first record of their association with lichens was made by Dillenius[701], who indicates the presence of black tubercles on the thallus of Physcia ciliaris. He figures them also on several species of Cladonia, on Ramalina and on Dermatocarpon, but without any suggestion as to their function. Hedwig’s[702] study of the reproductive organs of the Linnaean Cryptogams included lichens. He examined Physcia ciliaris, a species that not only is quite common but is generally found in a fruiting condition and with very prominent spermogonia, and has been therefore a favourite lichen for purposes of examination and study. Hedwig describes and figures not only the apothecia but also those other bodies which he designates as “punctula mascula,” or again as “puncta floris masculi.” In his later work he gives a drawing of Lichen (Gyrophora) proboscideus, with two of the spermogonia in section.
Acharius[703] included them among the lichen structures which he called “cephalodia”: he described them as very minute tubercles rising up from the substance of the thallus and projecting somewhat above it. He also figures a section through two “cephalodia” of Physcia ciliaris. Fries[704] looked on them as being mostly “anamorphoses of apothecia, the presence of abortive fruits transforming the angiocarpous lichen to the appearance of a gymnocarpous form.” Wallroth[705] assigned the small black fruits to the comprehensive fungus genus Sphaeria or classified lichens bearing spermogonia only as distinct genera and species (Pyrenothea and Thrombium). Later students of lichens—Schaerer[706], Flotow[707], and others—accepted Wallroth’s interpretation of their relation to the thallus, or they ignored them altogether in their descriptions of species.