Green lichen on petrified wood.
Colorful lichen on a piece of petrified wood


Mutually Beneficial

In many areas of Petrified Forest National Park, large collections of exposed rock surfaces are covered by lichens. A lichen is a simple community of at least two mutually-dependent organisms: fungi and green algae. Green algae uses the photosynthesis process to produce food for the fungus, while the fungus protects the algae from the elements and extracts nutrients from soil and rock. The lichen structure is more elaborate and durable than either fungus or algae alone. When organisms of different species are dependent on the other and benefit from each other's activity, they have a mutualistic symbiotic relationship.

Light green and black lichen
Light green and black lichen


Many other plants benefit from the presence of lichens. The green algae component of lichens can transform nitrogen in the air, which is unusable to most organisms, into a form which is essential for life. This is especially important in arid climates where lack of nitrogen is known to limit productivity.
Lichen on petrified log
Different types of lichen on a petrified log


Air & Water

Lichens are well adapted to arid climates. They can absorb more than their own weight of water and can absorb ephemeral water, such as dew, almost directly into their cells. The water does not need to go through roots and stems as it does in vascular plants.

Furthermore, lichens can continue food production at any temperature above freezing.

Orange lichen
Orange lichen


Because lichens take everything they need from the air, they are dependent on good air quality. Scientists turn to lichens as indicators of air quality.

Lichens of Petrified Forest National Park

Acarospora badiofusca (Nyl.) Th. Fr.

Acarospora fuscata (Schrader) Arnold Davis1992

Acarospora oligospora (Nyl.) Arnold Davis1992

Acarospora schleicheri (Ach.) A. Massal. Davis1992

Acarospora smaragdula (Wahlenb.) A. Massal. Davis1992

Acarospora stapfiana (Müll. Arg.) Hue Davis1992

Acarospora strigata (Nyl.) Jatta Davis1992

Amandinea punctata (Hoffm.) Coppins & Scheid. Davis1992

Arthonia clemens (Tul.) Th. Fr. Davis1992

Arthonia intexta Almq. Davis1992

Aspicilia caesiocinerea (Nyl. ex Malbr.) Arnold Davis1992

Aspicilia calcarea (L.) Mudd Davis1992

Aspicilia quartzitica W. A. Weber Davis1992

Biatora turgidula (Fr.) Nyl. Davis1992

Buellia dispersa A. Massal. Davis1992

Buellia spuria (Schaerer) Anzi Davis1992

Caloplaca arenaria (Pers.) Müll. Arg. Davis1992

Caloplaca cerina (Hedwig) Th. Fr. Davis1992

Caloplaca chrysophthalma Degel. Davis1992

Caloplaca decipiens (Arnold) Blomb. & Forss. Davis1992

Caloplaca decipiens (Arnold) Blomb. & Forss. Wetmore & Kärnefelt1998

Caloplaca epithallina Lynge Davis1992

Caloplaca holocarpa (Hoffm. ex Ach.) A. E. Wade Davis1992

Caloplaca microphyllina (Tuck.) Hasse Davis1992

Caloplaca saxicola (Hoffm.) Nordin Davis1992

Caloplaca subsoluta (Nyl.) Zahlbr. Davis1992

Caloplaca trachyphylla (Tuck.) Zahlbr. Wetmore & Kärnefelt1998

Caloplaca trachyphylla (Tuck.) Zahlbr. Davis1992

Candelariella aurella (Hoffm.) Zahlbr. Davis1992

Candelariella rosulans (Müll. Arg.) Zahlbr. Davis1992

Candelariella spraguei (Tuck.) Zahlbr. Davis1992

Candelariella subdeflexa (Nyl.) Lettau Davis1992

Candelariella vitellina (Hoffm.) Müll. Arg. Davis1992

Carbonea vitellinaria (Nyl.) Hertel Davis1992

Catapyrenium cinereum (Pers.) Körber Davis1992

Catapyrenium compactum (A. Massal.) R. Sant. Davis1992

Collema coccophorum Tuck. Davis1992

Collema fuscovirens (With.) J. R. Laundon Davis1992

Collema polycarpon Hoffm. Davis1992

Collema tenax (Sw.) Ach. Davis1992

Collema texanum Tuck. Davis1992

Dermatocarpon miniatum (L.) W. Mann Davis1992

Dermatocarpon moulinsii (Mont.) Zahlbr. Davis1992

Diploschistes actinostomus (Ach.) Zahlbr. Davis1992

Diplotomma alboatrum (Hoffm.) Flotow Davis1992

Endocarpon pusillum Hedwig Davis1992

Flavoparmelia baltimorensis (Gyelnik & Fóriss) Hale Davis1992

Fulgensia desertorum (Tomin) Poelt Davis1992

Heppia lutosa (Ach.) Nyl. Davis1992

Lecanora argopholis (Ach.) Ach. Davis1992

Lecanora crenulata (Dicks.) Hook. Davis1992

Lecanora dispersa (Pers. ) Sommerf. Davis1992

Lecanora garovaglii (Körber) Zahlbr. Davis1992

Lecanora muralis (Schreber) Rabenh. Davis1992

Lecanora nashii B. D. Ryan Davis1992

Lecanora novomexicana H. Magn. Davis1992

Lecanora opiniconensis Brodo Davis1992

Lecanora valesiaca (Müll. Arg.) Stizenb. Davis1992

Lecidea lithophila (Ach.) Ach. Davis1992

Lecidea tessellata Flörke Davis1992

Lecidella stigmatea (Ach.) Hertel & Leuckert Davis1992

Lepraria lobificans Nyl. Davis1992

Lepraria membranacea (Dickson) Vainio Davis1992

Lepraria neglecta (Nyl.) Erichsen Davis1992

Lichinella nigritella (Lettau) Moreno & Egea Davis1992

Lobothallia alphoplaca (Wahlenb.) Hafellner Davis1992

Lobothallia praeradiosa (Nyl.) Hafellner Davis1992

Melanelia tominii (Oksner) Essl. Davis1992

Neofuscelia atticoides (Essl.) Essl. Davis1992

Neofuscelia verruculifera (Nyl.) Essl. Davis1992

Phaeophyscia hirsuta (Mereschk.) Essl. Davis1992

Physcia caesia (Hoffm.) Fürnr. Davis1992

Physcia dubia (Hoffm.) Lettau Davis1992

Physcia subtilis Degel. Davis1992

Physconia detersa (Nyl.) Poelt Davis1992

Physconia muscigena (Ach.) Poelt Davis1992

Placidium acarosporoides (Zahlbr.) Breuss Davis1992

Placidium lachneum (Ach.) Breuss Davis1992

Placopyrenium stanfordii (Herre) K. Knudsen Davis1992

Placynthiella uliginosa (Schrader) Coppins & P. James Davis1992

Polysporina lapponica (Ach. ex Schaerer) Degel. Davis1992

Polysporina lapponica (Ach. ex Schaerer) Degel. Triebel et al.1991

Polysporina simplex (Davies) Vezda Davis1992

Psora decipiens (Hedwig) Hoffm. Davis1992

Psora russellii (Tuck.) A. Schneider Davis1992

Rhizocarpon geminatum Körber Davis1992

Rhizocarpon polycarpum (Hepp) Th. Fr. Davis1992

Rhizoplaca chrysoleuca (Sm.) Zopf Davis1992

Rhizoplaca melanophthalma (DC.) Leuckert & Poelt Davis1992

Rhizoplaca peltata (Ramond) Leuckert & Poelt Davis1992

Rinodina milvina (Wahlenb.) Th. Fr. Davis1992

Rinodina zwackhiana (Kremp.) Körber Davis1992

Staurothele areolata (Ach.) Lettau Davis1992

Staurothele drummondii (Tuck.) Tuck. Davis1992

Staurothele drummondii (Tuck.) Tuck. Thomson1991

Staurothele elenkinii Oksner Thomson1991

Staurothele monicae (Zahlbr.) Wetmore Davis1992

Stigmidium fuscatae (Arnold) R. Sant. Davis1992

Stigmidium fuscatae (Arnold) R. Sant. Triebel et al.1991

Toninia sedifolia (Scop.) Timdal Davis1992

Toninia tristis (Th. Fr.) Th. Fr. Davis1992

Verrucaria dacryodes Nyl. Davis1992

Verrucaria fuscella (Turner) Winch Davis1992

Xanthoparmelia ajoensis (T. Nash) Egan Davis1992

Xanthoparmelia conspersa (Ehrh. ex Ach.) Hale Davis1992

Xanthoparmelia cumberlandia (Gyelnik) Hale Davis1992

Xanthoparmelia lineola (E. C. Berry) Hale Davis1992

Xanthoparmelia maricopensis T. Nash & Elix Davis1992

Xanthoparmelia mexicana (Gyelnik) Hale Davis1992

Xanthoparmelia novomexicana (Gyelnik) Hale Davis1992

Xanthoparmelia plittii (Gyelnk) Hale Davis1992

Xanthoparmelia psoromifera (Kurok.) Hale Davis1992

Xanthoparmelia subdecipiens (Vainio) Hale Davis1992

Xanthoparmelia weberi (Hale) Hale Davis1992

Xanthoria candelaria (L.) Th. Fr. Davis1992

Xanthoria elegans (Link) Th. Fr. Davis1992

Xanthoria sorediata (Vainio) Poelt Davis1992

This list was generated on September 3, 2009 by NPLICHEN,, a database of lichens in the U.S. National Parks that was developed by James Bennett and Clifford Wetmore.

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Petrified Forest, AZ 86028


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