Lichens are classified by their fungal components. The name
given to lichens is actually the name of its fungal component. Therefore,
the identity of the photobiont does not determine the taxonomic grouping
of a lichen.
The taxonomic classification of C. coralloides is as follows:
Kingdom: Fungi: have non-motile bodies made up of apically elongating
filaments called hyphae, a life cycle with sexual and asexual reproduction,
haploid thalli resulting from zygotic meiosis, and heterotrophic
nutrition. Spindle pole bodies, not centrioles, usually are associated
with the nuclear envelope during cell division. The characteristic
wall components are chitin (beta-1,4-linked homopolymers of N-acetylglucosamine
in microcrystalline state) and glucans primarily alpha-glucans
(alpha-1,3- and alpha-1,6- linkages) (Griffin, 1993 as cited in
Division: Ascomycota: is the division of sac-forming fungi. This
is the largest group of fungi and at least 15,000 of them form lichens. These
fungi are grouped together because they hold their spores in sacs called
asci, which are organized within the fertile tissue. However,
some lichenologists and mycologists think that lichens should be grouped
together into a division of their own, Lichenes.
Order: Lecanorales: fruiting bodies are apothecia.
Family: Teloschistaceae: This family is made up of crustose,
foliose and fruticose lichens that have lecanorine apothecia (lecanorine
means that the margin of the apothecium contains photobionts and is
similar in color and texture to the thallus) with (usually) orange
apothecial discs (anthraquinones present). Spores are colorless and
polarilocular. Members of the family Teloschistaceae usually live on
trees and rocks from arctic to temperate regions. The genera within
the family Teloschistaceae are Caloplaca, Blasteni, Fulgensia, Gasparrinia, Teloschistes
-Lichen families are generally characterized by the
structure of their fruiting bodies.
Genus: Caloplaca: is a large heterogeneous group of mostly
crustose species. All of the species of Caloplaca have orange
apothecial disks that react deep red/purple with KOH (because they
have anthraquinones); sometimes the thallus and vegetative structures
also react deep red/purple with KOH. Spores are colorless, two-celled
-Lichen genera can be told apart by the color and septation
of their ascospores.
Species: coralloides: is a dwarf fruticose growth form.
The thallus is greenish yellow to orangeish yellow in color. The thin
yellow prothallus is sometimes present around the base of branches.
The branches are terete and dichotomous to subdichotomously branched.
The thallus of C. coralloides is nodulose and has pseudocyphellae.
Algae are present in scattered clumps below the cortex and hypothecium.
Apothecia can be absent or present, but are common and 0.4-2.0 mm in
size. Apothecia are present terminally or laterally on branches. The
apothecial disc can be concave, flat or convex and is darker orange
than the rest of the thallus. The hymenium (fertile layer in apothecia)
is 65-90 um thick; paraphyses (vertically oriented hyphae in hymenium)
are mostly unbranched but occasionally branched. The spores of C.
coralloides are polaribilocular or two-celled, ellipsoid and colorless.
Pycnidia mostly present and abundant and are immersed to somewhat raised,
orange, and slightly glossy. The major cortical pigment is parietin,
but C. coralloides also has emodin, teloschistin, parietinic
acid and fallacinal. C. coralloides is confined to the coast
and grows in the lower part of the supralittoral zone mostly on vertical
surfaces of hard rocks. C. coralloides is not sorediate.
- Lichen species are delineated somewhat randomly by
the structure of the ascocarp and vegetative characters. The more complex foliose
and fruticose lichens are usually separated by the presence or absense of soredia,
isidia, cilia, pseudocyphellae and lobules, and by the type of rhizines, the
structure of the exciple, spore size and septation and chemistry.
The Photobiont: Trebouxia
The green algal component of C. coralloides is most likely Trebouxia,
the most common green algal photobiont in lichens. The taxonomy of Trebouxia is
Cyanobacteria can also be photobionts in lichens (although this is
not the case in C. coralloides). The most common cyanobacteria
lichen photobiont is Nostoc, which is found in most jelly lichens.