Coenogonium

''Coenogonium'' is a genus of crustose lichens in the monotypic family Coenogoniaceae. It has about 90 species. Most species are leaf-dwelling or grow on bark, although a few are known to grow on rocks under certain conditions, and some are restricted to growth on termite nests. The genus was circumscribed in 1820 by German naturalist Christian Gottfried Ehrenberg.

''Coenogonium'' has a worldwide distribution, with most species known from tropical areas. Most species grow in tropical rain forests in the shaded understorey. They typically inhabit tree trunks, branches, lianas, and leaves.

Description

Although members of ''Coenogonium'' are relatively easy to identify given its unique characteristics, identifying to species is more difficult due to the slight differences between them. The genus is characterized by biatorine with a paraplectenchymatous excipulum, partially amyloid hymenium (I+ blue then quickly sordid green then red-brown), thin-walled unitunicate asci, and 1-septate or rarely non-septate ascospores. The photobiont from the family Trentepohliaceae. The structure of the ''Coenogonium'' thallus is largely determined by the algal partner.

Similar genera include ''Malcolmiella'', which differs mainly by having amyloid asci with a thickened tholus and non-septate, usually longer and broader ascospores with an ornamented perispore; ''Absconditella'', which has a chlorococcoid photobiont and non-amyloid asci; and ''Cryptodiscus'', which has ''Gloeocystis'' as photobiont, amyloid asci with a thickened apex and non-septate paraphyses.

Research

Species of ''Coenogonium'' have frequently used in morphological/anatomical and ecophysiological studies. Examples include thallus growth, apothecial development, ultrastructure, photobiont and resynthesis in culture, and photosynthesis. The filamentous thalli of ''Coenogonium'' serve as a home for diatoms and other microorganisms. Johannes Müller Argoviensis even used his erroneous interpretation of the thallus organization of filamentous ''Coenogonium'' to oppose Simon Schwendener's theory of the symbiotic nature of lichens.

Species

The genus is quite well known in continental areas that border the Caribbean, such as Florida and Costa Rica. About half of the world's biodiversity of this genus occurs in Brazil.

*''Coenogonium aciculatum'' – Costa Rica
*'' Coenogonium agonimioides''
*'' Coenogonium albomarginatum''
*''Coenogonium antonianum''
*''Coenogonium atroluteum'' – Neotropics
*''Coenogonium aurantiacum'' – Puerto Rico
*''Coenogonium bacilliferum''
*''Coenogonium barbatellum''
*''Coenogonium barbatum'' – Costa Rica
*''Coenogonium beaverae''
*''Coenogonium borinquense'' – Puerto Rico
*''Coenogonium botryosum''
*''Coenogonium brasiliense''
*''Coenogonium bryophilum'' – Australia
*''Coenogonium byssothallinum'' – Costa Rica
*''Coenogonium chloroticum'' – Brazil
*'' Coenogonium ciliatum''
*'' Coenogonium confervoides''
*'' Coenogonium convexum'' – Thailand
*''Coenogonium coppinsii'' – Brazil
*''Coenogonium coralloideum''
*''Coenogonium coronatum''
*''Coenogonium curvulum''
*''Coenogonium dattatreyense''
*''Coenogonium davidii''
*''Coenogonium degeneri''
*''Coenogonium dilucidum''
*'' Coenogonium dimorphicum'' – Puerto Rico
*''Coenogonium disciforme'' – Thailand
*''Coenogonium eximium'' – Neotropics
*''Coenogonium fallaciosum''
*'' Coenogonium flammeum''
*''Coenogonium flavicans''
*'' Coenogonium flavovirens''
*'' Coenogonium flavoviride''
*''Coenogonium flavum''
*''Coenogonium frederici''
*''Coenogonium fruticulosum'' – New Zealand
*''Coenogonium fuscescens''
*''Coenogonium geralense'' – pantropical
*''Coenogonium hainanense'' – China
*''Coenogonium hypophyllum''
*''Coenogonium implexum''
*'' Coenogonium interplexum''
*''Coenogonium interpositum''
*''Coenogonium isidiatum''
*'' Coenogonium isidiiferum''
*'' Coenogonium isidiigerum''
*''Coenogonium isidiosum''
*'' Coenogonium kalbii'' – Costa Rica
*'' Coenogonium kawanae''
*''Coenogonium kiggaense''
*''Coenogonium labyrinthicum''
*''Coenogonium linkii''
*''Coenogonium lisowskii''
*''Coenogonium lueckingii''
*'' Coenogonium luteocitrinum'' – Neotropics
*''Coenogonium luteolum'' – Europe
*''Coenogonium lutescens''
*''Coenogonium luteum''
*''Coenogonium magdalenae'' – Costa Rica
*''Coenogonium maritimum'' – Florida
*''Coenogonium minidenticulatum''
*''Coenogonium minimum''
*''Coenogonium minutissimum''
*'' Coenogonium moniliforme''
*''Coenogonium nepalense'' – Neotropics and eastern Paleotropics
*'' Coenogonium perminutum''
*'' Coenogonium persistens'' – Neotropics
*''Coenogonium pertenue''
*''Coenogonium piliferum''
*'' Coenogonium pineti''
*''Coenogonium platysporum''
*''Coenogonium pocsii'' – African Paleotropics
*''Coenogonium portoricense'' – Puerto Rico
*''Coenogonium pulchrum''
*''Coenogonium pusillum''
*''Coenogonium pyrophthalmum''
*''Coenogonium queenslandicum'' – eastern Paleotropics
*''Coenogonium riparium''
*''Coenogonium roumeguerianum''
*''Coenogonium rubrofuscum''
*''Coenogonium saepincola'' – Costa Rica
*''Coenogonium seychellense''
*'' Coenogonium siquirrense''
*''Coenogonium stenosporum'' – Neotropics
*''Coenogonium stramineum''
*''Coenogonium strigosum'' – Neotropics
*''Coenogonium subborinquense'' – Thailand
*''Coenogonium subdentatum'' – Neotropics; eastern Paleotropics
*''Coenogonium subdilucidum''
*''Coenogonium subdilutum''
*''Coenogonium subdilutum''
*''Coenogonium subfallaciosum''
*''Coenogonium subluteum''
*''Coenogonium subsquamosum''
*'' Coenogonium subzonatum''
*''Coenogonium tanzanicum''
*''Coenogonium tavaresianum''
*''Coenogonium theae''
*'' Coenogonium upretianum'' – Brazil
*'' Coenogonium usambarense'' – African and eastern Paleotropics
*''Coenogonium verrucimarginatum'' – Thailand
*'' Coenogonium verrucosum'' – South America
*''Coenogonium vezdanum''
*'' Coenogonium weberi''
*''Coenogonium wernerhuberi'' – Costa Rica
*''Coenogonium wrightii''
*'' Coenogonium zonatum''

References

{{Taxonbar, from=Q10456565, from2=Q2981793

Gyalectales
Gyalectales genera
Lichen genera
Taxa described in 1820
Taxa named by Christian Gottfried Ehrenberg