The PARMELIACEAE is a large and diverse family of
With over 2000 species in roughly 87 genera , it is regarded as the
largest family of lichen forming fungi . The most speciose genera in
the family are the well-known groups:
Xanthoparmelia (800+ species),
Usnea (500+ species),
Parmotrema (350+ species), and Hypotrachyna
Nearly all members of the family have a symbiotic association with a
green alga (most often
Trebouxia spp., but Asterochloris spp. are
known to associate with some species). The majority of Parmeliaceae
species have a foliose, fruticose, or subfruticose growth form. The
morphological diversity and complexity exhibited by this group is
enormous, and many specimens are exceedingly difficult to identify
down to the species level.
The family has a cosmopolitan distribution , and can be found in a
wide range of habitats and climatic regions . This includes
everywhere from roadside pavement to alpine rocks, from tropical
rainforest trees to subshrubs in the arctic tundra. Members of the
Parmeliaceae can be found in most terrestrial environments.
* 1 Taxonomy
* 2 Characteristics
* 2.1 Thallus
* 2.2 Apothecia
* 2.3 Spores
* 2.4 Chemistry
* 2.5 Photobiont
* 4 Image gallery
* 5 Notable taxa
* 6 References
* 7 External links
Based on several molecular phylogenetic studies, the
currently circumscribed has been shown to be a monophyletic group.
This circumscription is inclusive of the previously described families
Alectoriaceae, Anziaceae, Hypogymniaceae, and Usneaceae, which are all
no longer recognised by most lichen systematists . However, despite
the family being one of the most thoroughly studied groups of lichens,
several relationships within the family still remain unclear.
Phylogenetic analysis tentatively supports the existence of six
separate clades in the family:
* Alectorioid clade (3 genera)
* Cetrarioid clade (8 genera)
* Hypogymnioid clade (4 genera)
* Letharioid clade (2 genera)
* Parmelioid clade (26 genera)
* Psiloparmelioid clade (2 genera)
However, this still leaves roughly 42
Parmeliaceae genera unplaced.
Parmeliaceae thalli are most often foliose, fruticose or
subfruticose, but can be umblicate, peltate, caespitose, crustose, or
subcrustose. One genus, Nesolechia , is even a lichenicolous fungus.
They can be a variety of colours, from whitish to grey, green to
yellow, or brown to blackish (or any combination therein). Many genera
are lobe forming, and nearly all are heteromerous (which are corticate
on both sides).
Species are usually rhizinate on the lower surface,
occasionally with holdfasts, rhizohyphae, or a hypothallus. Only a few
genera have a naked lower surface (for example
Menegazzia ). The upper surface has a pored or non-pored epicortex.
Medulla is solid, but often loosely woven.
Apothecia are lecanorine, produced along the lamina or margin, and
sessile to pedicellate (or less often sunken). Thalline exciple is
concolorous with the thallus. Asci are amyloid, and the vast majority
of species have eight spores per ascus, though a few species are
many-spored, and several
Menegazzia species have two spores per ascus.
Ascospores are simple, hyaline , and often small. Conidia generally
arise laterally from the joints of conidiogenous hyphae (Parmelia
-type), but arise terminally from these joints in a small number of
Psora -type). The conidia can have a broad range of shapes:
cylindrical to bacilliform, bifusiform, fusiform, sublageniform,
unciform, filiform, or curved. Pycnidia are immersed or rarely
emergent from the upper cortex, are produced along the lamina or
margins, pyriform in shape, and dark-brown to black in colour.
Members of the
Parmeliaceae exhibit a diverse chemistry, with several
types of lichenan (
intermediate-type), isolichenan and/or other polysaccharides being
known from the cell walls of many species.
The main photobiont genus that associates with
Trebouxia . In particular the species Trebouxia
jamesii appears to be especially prominent. Some
are also known to associate with Asterochloris, but the frequence of
this association is not yet known. In general photobiont diversity
Parmeliaceae is a little studied subject, and much is left
to discover here.
List of Parmeliaceae genera
Menegazzia pertransita growing on a tree in
New Zealand . Scale bar =
Cetraria nivalis from
Parmelia sulcata from Commanster,
Usnea rubicunda growing on a branch in Mendocino County,
Allocetraria oakesiana growing on bark in Highland County,
Alectoria ochroleuca from Carianthia,
Everniastrum catawbiense from Steuben,
Xanthoparmelia cf. lavicola, on basalt in
Hypogymnia cf. tubulosa in
Letharia vulpina at Mt. Gleason,
Some well known members of the
* the genus Parmelia
* the genus
Usnea (old man's beard)
Oakmoss (Evernia prunastri)
Iceland moss (
* Wila (Bryoria fremontii)
* ^ A B Bisby, Guy Richard; Ainsworth, G. C.; Kirk, P. M.; Aptroot,
André (2001). Ainsworth with the assistance of A. Aptroot... Oxon:
CAB International. p. 378. ISBN 0-85199-377-X .
* ^ A B C Crespo, A.; Lumbsch, H. T.; Mattsson, J. E.; Blanco, O.;
Divakar, P. K.; Articus, K.; Wiklund, E.; Bawingan, P. A.; Wedin, M.
(August 2007). "Testing morphology-based hypotheses of phylogenetic
Parmeliaceae (Ascomycota) using three ribosomal
markers and the nuclear RPB1 gene". Molecular Phylogenetics and
Evolution . 44 (2): 812–824. PMID 17276700 . doi
* ^ A B Miadlikowska, J. et al. (2006). New insights into
classification and evolution of the
Ascomycota) from phylogenetic analyses of three ribosomal RNA- and two
protein-coding genes. Mycologia 98: 1088-1103.
* ^ Cannon PF, Kirk PM (2007). Fungal Families of the World.
Wallingford: CABI. p. 256. ISBN 0-85199-827-5 .
* ^ Crespo Ana; Blanco, Oscar; Hawksworth, David L (2001). "The
potential of mitochondrial DNA for establishing phylogeny and
stabilising generic concepts in the parmelioid lichens". Taxon. 50
JSTOR 1223708 . doi :10.2307/1223708 .
* ^ A B C D Elix, J.A. (1994). Parmeliaceae. Flora of Australia –