Public Description of Peltigera Willd.

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Name: Peltigera Willd.
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Description status: Unreviewed
 (Latest review: 2012-04-02 19:52:14 CDT (-0500) by jason)

Taxonomic Classification:

Domain: Eukarya
Kingdom: Fungi
Phylum: Ascomycota
Class: Lecanoromycetes
Order: Peltigerales
Family: Peltigeraceae


General Description:

This is large genus of broad, loosely-attached, foliose lichens. Most grow on the ground or logs over soil or moss, however many can be found at the base of trees or, in a few cases as true epiphytes (P. collina). There are even a couple of aquatic species (P. gowardii and P. hydrohyria). Most are cyanolichens (photobiont is a cyanobacterium instead of a green alga) with variable color ranging from pale to dark brown or gray, sometimes with a distinct bluish tint, especially when damp. Others contain both green algae (primary photobiont, in the thallus) and cyanobacteria (secondary photobiont, confined to small cephalodia on the upper surface or in the case of P. venosa) lower surface). These are vivid grass-green when damp, fading to pale gray or brownish gray when dry.

All species have rhizines and veins to varying extents on the lower surface (though see P. malacea and P. elisabethae for example). The only other genus with this characteristic is the closely-related Solorina. Many species also have a thin tomentum on the upper surface. Most species are fertile, however a few are sorediate, isidiate, or phyllidiate. Apothecia are typically borne on distinctive erect, finger-like projection on the margins of the thallus (though see P. venosa and P. horizontalis).


Diagnostic Description:

Broad, loosely-attached, foliose, mostly terricolous lichens with veins and rhizines on lower surface, often with tomentum both above and below.


Distribution:

Cosmopolitan, with the center of diversity found in central British Columbia, Canada.


Habitat:

Mostly found on logs, ground, mossy rocks, or base of trees in shaded, moist habitats. Some found in exposed, dry situtations. Some exclusively found on recently-disturbed soil banks. One species typically epiphytic.


Look Alikes:

Solorina also has veins and rhizines, however its apothecia are found in sunken depressions in the center of its lobes, instead of around the margin.

Nephroma can be very similar in appearance, but it lacks veins and rhizines, and its apothecia are borne underneath “paw-like” marginal projections.

Other cyanolichens in the Peltigerineae suborder often have similar overall appearance and are found in similar habitats. Examples are Lobaria, Pseudocyphellaria, Sticta. But none of these have veins or rhizines. See also Coccocarpia and Pannaria.


References:

Burgaz, A.R. & I. Martínez. 2003. Peltigerales: Lobariaceae, Nephromataceae, Peltigeraceae. Flora Liquenológica Ibérica. Murcia, Spain: Sociedad Española de Liquenologia.

Goffinet, B. & R.I. Hastings. 1995. Two new sorediate taxa of Peltigera. Lichenologist 27(1): 43-58.

Goffinet, B. & J. Miadlikowska. 1999. Peltigera phyllidiosa (Peltigeraceae, Ascomycotina), a new species from the southern Appalachians corroborated by ITS sequences. Lichenologist 31(3): 247-256.

Goffinet, B., J. Miadlikowska & T. Goward. 2003. Phylogenetic inferences based on nrDNA sequences support five morphospecies within the Peltigera didactyla complex (lichenized Ascomycota). The Bryologist 106(2): 349-364.

Goward, T., B. Goffinet and O. Vitikainen. 1994. Synopsis of the genus Peltigera in British Columbia, with a key to the North American species. Canadian Journal of Botany. 73: 91-111.

Goward, T. & B. Goffinet. 2000. Peltigera chionophila, a new lichen (Ascomycetes) from the Western Cordillera of North America. The Bryologist 103(3): 493-498.

Hitch, C.J.B., A. Fletcher, P.W. James & O.W. Purvis. 2009. Peltigera, pages 664-674. In The Lichens of Great Britain and Ireland. Natural History Museum Publications, Lnondon, U.K.

Holtan-Hartwig, J. 1988. Two new species of Peltigera. Lichenologist 20: 11-17.

Holtan-Hartwig, J. 2005. Peltigera latiloba, a new lichen species from Norway and USA (Alaska). Graphis Scripta 17(2): 34.

Lendemer, J.C. & H. O’Brien. 2011. How do you reconcile molecular and non-molecular datasets? A case study where new molecular data prompts a revision of Peltigera hydrothyria s.l. in North America and the recognition of two species. Opuscula Philolichenum 9: 99-111.

Louwhoff, S.H.J.J. 2009. Peltigera in Flora of Australia, vol. 57.
http://www.anbg.gov.au/abrs/lichenlist/Peltigera%20gen.pdf

Martínez, I., A.R. Burgaz, O. Vitikainen & A. Escudero. 2003. Distribution patterns in the genus Peltigera. Lichenologist 35(4): 301-323.
Goffinet, B. & J. Miadlikowska. 1999. Peltigera phyllidiosa, a new species from the southern Appalacians corroborated by ITS sequences. Lichenologist 31(3): 247-256.

Miadlikowska, J. & F. Lutzoni. 2000. Phylogenetic revision of the genus Peltigera based on morphological, chemical, and large subunit nuclear ribosomal DNA data. International Journal of Plant Science 161(6):9
25-958.

Thomson Jr., J.W. 1950. The species of Peltigera of North America north of Mexico. American Midland Naturalist. 44(1): 1-68.

Vitikainen, O. 1994. Taxonomic revision of Peltigera (lichenized Ascomycotina) in Europe. Acta Botanica Fennica 152: 1-96.

Vitikainen, O. 2002. Notes on Peltigera in southern South America and Antarctic regions. Mitteilungen aus dem Institut für Allgemeine Botanik Hamburg. 30-32: 297-303.

Vitikainen, O. 2004. Peltigera, pp. 389-399. In T.H. Nash III, B.D. Ryan, P. Diederich, C. Gries & F. Bungartz (eds.), Lichen Flora of the Greater Sonoran Desert Region, Vol. 2. Lichens Unlimited, Arizona State University, Tempe, Arizona.

Vitikainen, O. 2006. Peltigera tartarea, a new species from Arctic America. Journal of the Hattori Botanical Laboratory 100: 853-854.

Vitikainen, O. 2007. Peltigera. Nordic Lichen Flora 3: 129-131.

Wiklund, E. & M. Wedin. 2003. The phylogentic relationships of the cyanobacterial lichens in the Lecanorales suborder Peltigerineae. Cladistics. 19: 419-431.


Notes:

Taxonomy of Peltigera relies heavily on subtle morphological characteristics of the veins and rhizines of the lower surface. Positive ID of most species requires an unobstructed view of the lower surface back 1-2 cm from the margins.

The genus can be broken up readily into five major groups:

P. aphthosa group – Broad-lobed species containing green algae and “freckles” (cephalodia scattered over upper surface). This group also includes P. malacea which is essentially just the cyanomorph of a species which has lost the ability to grow with green algae. Examples: P. leucophlebia, P. britannica, P. chionophila.

P. canina group – Species with tomentose upper surface, at least near the tips. This group includes the P. didactyla group, a set of very similar tiny sorediate species. This group includes P. degenii, with a dull but glabrous upper surface. Examples: P. membranacea, P. rufescens, P. ponojensis, P. lepidophora, P. praetextata.

P. polydactylon group – Species with glabrous upper surface and brown finger-shaped apothecia. Examples: P. neopolydactyla, P. hymenina.

P. neckeri group – Species with glabrous upper surface and black finger-shaped apothecia. This group includes the sorediate species P. collina because it has black apothecia when fertile. Examples: P. phyllidiosa.

P. horizontalis group – Species with glabrous upper surface and brown disc-shaped apothecia. These species typically have rhizines arranged in concentric lines near the margins, too. Examples: P. elisabethae.


Description author: Jason Hollinger (Request Authorship Credit)


Created: 2012-04-02 19:21:38 CDT (-0500) by Jason Hollinger (jason)
Last modified: 2012-04-02 19:52:14 CDT (-0500) by Jason Hollinger (jason)
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