Review articles

By Ms. Poorna Kantheti , Dr. John O Igoli , Dr. Alexander I Gray , Dr. Carol J Clements , Mr. Rajeev K Singla
Corresponding Author Dr. John O Igoli
Natural Product Laboratories, SIPBS, University of Strathclyde, 161 Cathedral Street Glasgow G4 0RE,, - United Kingdom
Submitting Author Mr. Rajeev K Singla
Other Authors Ms. Poorna Kantheti
Natural Product Laboratories, SIPBS, University of Strathclyde, 161 Cathedral Street Glasgow G4 0RE,, - United Kingdom

Dr. Alexander I Gray
Natural Product Laboratories, SIPBS, University of Strathclyde, 161 Cathedral Street Glasgow G4 0RE,, - United Kingdom

Dr. Carol J Clements
Natural Product Laboratories, SIPBS, University of Strathclyde, 161 Cathedral Street Glasgow G4 0RE,, - United Kingdom

Mr. Rajeev K Singla
Division of Biotechnology, Netaji Subhas Institute of Technology, University of Delhi, Azad Hind Fau, - India


Parmeliaceae; Lichen; Medicinal Plants; Herbal Plants; Traditional Medicine; Pharmacology

Kantheti P, Igoli JO, Gray AI, Clements CJ, Singla RK. Parmeliaceae- An Important Family of Lichens with Medicinal Importance. WebmedCentral PHARMACEUTICAL SCIENCES 2012;3(11):WMC003807
doi: 10.9754/journal.wmc.2012.003807

This is an open-access article distributed under the terms of the Creative Commons Attribution License(CC-BY), which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
Submitted on: 04 Nov 2012 11:47:16 AM GMT
Published on: 06 Nov 2012 07:48:19 PM GMT


Life always coexists with disease, death and decay. To sustain a healthy and happy life, man has been applying his knowledge to discover the remedies for prevention and treatment of diseases since the human civilisation began. Plants were the natural sources mainly on which people totally depended to fight against diseases when there was no alternative.

The Parmeliaceae is the most diverse and large family of the order Lecanoromycetes. It has 87 genera which have more than 2000 species. It is considered as the largest family of fungi which forms lichens (These are the fungi which has a symbiotic relationship with algae). The main genera in the family are: Xanthoparmelia have more than 800 species, Usnea with more than 500 species, Parmotrema with more than 350 species and Hypotrachyna with more than 190 species.

Most of the members in the family have a symbiotic relationship with algae. The majority of species in Parmeliaceae have a fruticose, subfruticose or foliose form of growth. The huge variation in morphology and complexity is observed in members of this group. The family can be found in a wide range of climatic regions and habitats and has a cosmopolitan distribution. They can be found everywhere from alpine rocks to roadside pavement, from subshrubs in the arctic tundra to tropical rainforest trees. Members of this family can be found in almost all kinds of terrestrial environments.

Characteristics of Structure

• Thallus

• Apothecia

• Spores


Parmeliaceae thallus is mostly fruticose, foliose or subfruticose but also can be caespitose, umblicate, peltate, subcrustose or crustose. They can be seen in different colours from green to yellow, whitish to grey, or brown to black. Many genera are lobe forming. Species are usually rhizinate on the lower surface occasionally with rhizohyphae, hypothallus, or holdfasts. Epicortex the upper surface may have non-pored or pored surface. Medulla is often loosely woven but sometimes it is solid. Lower surface is naked in only some genera for example Menegazzia, Usnea and Hypogymnia. (literature at the burkes luck lichen trail, supplied by professor dirk wessels of the university of the north)


Apothecia are lecanorine and they are produced along the margin or lamina and pedicellate to sessile and sometimes sunken. Thalline exciple is concolourous with the thallus. Asci are amyloid along with the majority of species having 8 spores per ascus, few species have many spores and many species of Menegazzia have 2 spores per ascus.


Ascospores are often small, simple and hyaline. Conidia usually arise laterally from the joints of conidiogenous hyphae (Parmelia type), but arise terminally from these joints in a small number of species (Psora type). The conidia can have a wide range of shapes from bacilliform to fusiform, cylindrical, bifusiform, curved, unciform, sublageniform or filiform. Pycnidia are rarely emergent from the upper cortex or immersed are produced along the margins or lamina, pyriform shaped and can be seen from black to dark-brown in colour.

This family mostly contain lichens. Lichens are fungi which forms a symbiotic relationship with green alga or blue green alga (cyanobacterium) or both. These can be found almost in all type of habitats and substrates.

Linnaeus recognised and classified nearly 80 species in 1753. Erik Acharius called the father of lichenology was the first scientist who seriously studied lichens and also described many new species but Schwendener was the one who discovered the dual nature of lichens in 1869 before that the green structures within lichen were believed to be gonads but were actually green alga .The estimated number of lichen species range from 13,000 to 30,000 worldwide.

The majority of the lichens belong to family Ascomycota in which spores are produced inside asci. The evolution of lichens is very old; the oldest evidence of fossil lichen is from the Rhyne chert formation in Scotland which dates back to 400 million years ago.

In the lichen symbiosis, fungal partner is called mycobiont and algal partner is called photobiont. The mycobiont protects photobiont against dehydration and harmful UV radiations which enables the algal partner to survive in habitats which would be generally inaccessible. The mycobiont is also responsible for the shape and sexual reproductive structures of lichens. The photobiont plays its role in carrying out photosynthesis and producing carbohydrates which are metabolised by fungus. The characteristic unique secondary metabolite of lichen is actually produced by the mycobionts. If blue green alga is partner in symbiosis then the mycobiont can obtain nitrogen compounds because this alga is capable of fixing atmospheric nitrogen. Generally nutrients and water are taken directly through the surface of the lichen because of this they can even survive in low rainfall or moist regions.

Lichens are of different shapes and forms .They typically grows on bark, rock and soil but they can also grow on leaves, roof tiles, asphalt, metal surfaces and many other surfaces. Lichen body which is called thallus is composed of upper cortex containing tightly packed fungal hyphae below which is the photosynthetic algal layer. Below this layer is there is loosely woven cottony layer of fungal hyphae called medulla where most of the secondary metabolites are deposited as crystals. The fungal layer determines the secondary metabolites and is useful for identification.

Compared to plants, lichens grow very slowly ranging from less than a millimetre per year in case of micro-lichens to almost 10 cm per year in case of macro-lichens. Lichens are generally classified based on their growth form which is artificial classification system but used mainly for identifying lichens.

The most common categories are crustose, fruticose and foliose. Crustose lichens have a thallus which forms a blotch on the substratum on which it grows and is very difficult to remove without cutting a part of it. Fruticose lichens are bushy, pendulous or upright position. They are highly branched which helps in increasing the surface area. Foliose lichens appear flattened with a distinguishable upper and lower surface and they can be easily removed using a knife.

In Australia approximately more than 3500 species of lichens have been recorded and more than 35% of these are regarded as endemic (McCarthy 2009).They are greatest in numbers in Queensland (1796 species) which also contains endemic (260species), followed by NSW (1498 species) which contain 112 endemic species, then by Tasmania (1063 species) which contains 102 endemic species.

Economic importance of Lichens

Lichen is derived from the Greek word ‘Leprous’ and refers to medicine used for treatment of skin diseases because of their appearance as peeling skin. Lichens are used as source of food in many regions. For example cetraria islandica was used as food in Northern Europe and was cooked as porridge, soup, bread, salad and pudding. Some lichens known as Earth Flowers have a strong and distinct odour so they are smoked along with tobacco used in summer dances (Curtin, LSM. 1984).

Lichens such as Bryoria fremoontii were mostly used as food in times of famine in North America so they were called famine food. The extracts from lichens are used to dye wool and for production of ‘Harris Tweed’ of Scotland. They are also used in the manufacture of ‘moss’ and ‘leather’ fragrances in perfumes and some type of soaps (Richardson, D. H. S. 1974). In China, lichens are used as food (Lobaria isidiophra, L.yoshimurae) and also as health promoting tea (Thamnolia subuliformis, Lethariella cashmeriana).

Medicinal importance of Lichens

The metabolites (mainly secondary) produced by lichen exerts wide range of medicinal and biological properties like antimycobacterial, antiproliferative, antiviral, antibiotic, anti-inflammatory, cytotoxic, analgesic and antipyretic effects. Though their potential is known but they have not been explored fully (Muller, 2002).The secondary metabolites are the main compounds that are utilised for medicinal purposes (Boustie and Grube, 2005).

According to estimation more than half of the lichens have antibiotic property (Sharnoff, 1997). Usnic acid extracted from many lichens demonstrated wide spectrum antibiotic activity (Shibamoto and Wei, 1984, Rowe et al. 1991). Vulpinic acid exhibited mild antibiotic activity (Lauterwein et al.1995). These acids inhibited the growth of Bacillus subtilis, Staphylococcus aureus and Bacillus magaterium which are gram positive but did not have any effect on Escherichia coli which is gram negative (Lawrey, 1986). Alectosaementin, alectoronic acid and physodic acid were isolated from the alcoholic extract exhibited antimicrobial activity (Gollapudi et al. 1994).

The extract from acetone, chloroform, diethyl ether, petroleum ether and methanol of Parmelia sulcata Taylor, Parmelia sulcata exhibited antibacterial activity against Bacillus subtilis, Candida albicans and many other bacteria (Candan et al, 2007). Parietin and anthraquinone isolated from Caloplaca cerina methanol extract have demonstrated antifungal activity (Manojlovic, 2005). Phenolic constituents from lichen Parmotrema stuppeum include orsennilic acid, methyl orsenillate, lecanoric acid and atranorin exhibited antioxidant activity (Jayaprakasha and Rao, 2000).


Author Rajeev K Singla is receiving Young Scientist Fellowship from Science & Engineering Research Board(Department of Science & Technology), Government of India.


1. McCarthy, P.M. (2009), Checklist of the Lichens of Australia and its Island Territories. Australian Biological Resources Study, Canberra. Version 22, October 2009.
2. Curtin, LSM. 1984. EthnoDescription of the Pima (By the Prophet of the Earth). Univ. of Arizona Press. Page 77.
3. Richardson, D. H. S. 1974. Vanishing Lichens. Their History, Biology and Importance. 231 pp. HafnerPress, New York.
4. Muller K. 2002. Pharmaceutically relevant metabolites from lichens. Applied Microbiology and Biotechnology 56(1/2): 9-16.
5. Boustie J, Grube M. (2005). Lichens-a promising source of bioactive secondary metabolites. Plant Genetic Resources 3:273-278.
6. Sharnoff, S. D. 1997. Lichens and people
7. Shibamoto T, Wei CI. 1984. Mutagenicity of lichen constituents. Environmental Mutagenesis 6: 757-762.
8. Rowe G et al. 1999. Some lichen products have antimicrobial activity. Zeitschrift für Naturforschung 54(7-8):605-9.
9. Lauterwein M et al. 1995. In vitro activities of the lichen secondary metabolites vulpinic acid, (+)-usnic acid, and (-)-usnic acid against aerobic and anaerobic microorganisms. Antimicrobial Agents and Chemotherapy 39(11): 2541-2543.
10. Lawrey JD. 1986. Biological role of lichen substances. The Bryologist 89:111-122. Cocchietto M, Skert N, Nimis PL. 2002. A review on usnic acid, an interesting natural compound. Naturwissenschaften 89: 137-146.
11. Gollapudi SR et al. 1994. Alectosaementin, a new antimicrobial dibenzofuranoid lactol from the lichen, Alectoria sarmentosa. Journal of Natural Product 57(7):934-8.
12. Candan, M et al. 2007. Antimicrobial activity of extracts of the lichen Parmelia sulcata and its salazinic acid constituent. Zeitschrift für Naturforschung 62(7-8):619-21.
13. Manojlovic NT et al. 2005. Antifungal activity of Rubia tinctorum, Rhamnus frangula and Caloplaca cerina. Fitoterapia 76(2):244-6.
14. Jayapraksha GK, Rao LJ. 2000. Phenolic constituents from the lichen Parmotrema stuppeum (Nyl.) Hale and their antioxidant activity. Zeitschrift für Naturforschung 55(11-12):1018-22.

Source(s) of Funding

It is a net based article collecting and compiled data from google, google scholar, science direct, Springer, Wiley, Pub Med etc.

Competing Interests

No competing interests


This article has been downloaded from WebmedCentral. With our unique author driven post publication peer review, contents posted on this web portal do not undergo any prepublication peer or editorial review. It is completely the responsibility of the authors to ensure not only scientific and ethical standards of the manuscript but also its grammatical accuracy. Authors must ensure that they obtain all the necessary permissions before submitting any information that requires obtaining a consent or approval from a third party. Authors should also ensure not to submit any information which they do not have the copyright of or of which they have transferred the copyrights to a third party.
Contents on WebmedCentral are purely for biomedical researchers and scientists. They are not meant to cater to the needs of an individual patient. The web portal or any content(s) therein is neither designed to support, nor replace, the relationship that exists between a patient/site visitor and his/her physician. Your use of the WebmedCentral site and its contents is entirely at your own risk. We do not take any responsibility for any harm that you may suffer or inflict on a third person by following the contents of this website.

2 reviews posted so far

Review on
Posted by Dr. Ajit S Narang on 04 Dec 2012 12:44:28 AM GMT

2 comments posted so far

Almost The same Posted by Ms. Neha Narang on 05 Dec 2012 04:27:05 AM GMT

Please use this functionality to flag objectionable, inappropriate, inaccurate, and offensive content to WebmedCentral Team and the authors.


Author Comments
0 comments posted so far


What is article Popularity?

Article popularity is calculated by considering the scores: age of the article
Popularity = (P - 1) / (T + 2)^1.5
P : points is the sum of individual scores, which includes article Views, Downloads, Reviews, Comments and their weightage

Scores   Weightage
Views Points X 1
Download Points X 2
Comment Points X 5
Review Points X 10
Points= sum(Views Points + Download Points + Comment Points + Review Points)
T : time since submission in hours.
P is subtracted by 1 to negate submitter's vote.
Age factor is (time since submission in hours plus two) to the power of 1.5.factor.

How Article Quality Works?

For each article Authors/Readers, Reviewers and WMC Editors can review/rate the articles. These ratings are used to determine Feedback Scores.

In most cases, article receive ratings in the range of 0 to 10. We calculate average of all the ratings and consider it as article quality.

Quality=Average(Authors/Readers Ratings + Reviewers Ratings + WMC Editor Ratings)