Yellow Lichens (Parmelia perlata) – Properties, Uses & Dosage

Abstract

Parmelia perlata is a foliose lichen widely distributed across temperate and tropical regions, known for its ecological importance and ethnomedicinal applications. This lichen species plays a vital role in bioindication, nutrient cycling and serves as a host for diverse microbial communities. It has traditionally been used as a food source by the Rai and Limbu communities of eastern Nepal, and also serves as a natural light brown dye for wool. Additionally, it functions as a bioindicator for air pollution, particularly due to its sensitivity to heavy metal contamination. Despite its traditional use in Ayurvedic and tribal medicine, comprehensive scientific documentation remains limited. This article reviews the taxonomy, distribution, ecological significance and potential pharmacological applications of Parmelia perlata.

Yellow Lichens (Parmelia perlata), Herbs A to Z

Introduction

Lichens are complex symbiotic organisms composed of a fungal partner (mycobiont) and a photosynthetic partner (photobiont), typically an alga or cyanobacterium. Among them, the genus Parmelia is one of the most extensively studied due to its widespread distribution and environmental significance. This lichen has garnered attention not only for its ecological role in air quality assessment and habitat formation but also for its traditional use in indigenous medicine systems. Ethnobotanical reports suggest its application in treating wounds, respiratory disorders and skin ailments. It is commonly found across the steep regions of the Himalayas and Northeast India, where it grows among rocks, on tree trunks and across the forest floor. The lichen has a greenish-black and white outer layer, with a thallus that can reach up to 15 cm in diameter and is only loosely attached to the surface it grows on. Its upper surface is smooth, orbicular and greyish-white, while the underside is dark brown to blackish and covered with fine hairs.

Scientific Classification

Kingdom: Fungi
Division: Ascomycota
Class: Lecanoromycetes
Order: Lecanorales
Family: Parmeliaceae
Genus: Parmelia
Species: perlata

Synonyms

Shiladadru (Found in rocks)
Shilapushpa (Flowers are seen in between rocks)
Kalanusaryakam
Vriddha
Sthavira
Palita

Vernacular names

Arabian: Hinna-i-Korisha, Rumman, Barri, Shaibah, Shaibat
Ayurvedic: Bhuri-charilla, Shaila, Shaileya, Shailaka, Shaileyaka, Shailpushpa, Shilaapushpa, Shilaadaaru, Shilodbhava, Shitashiva, Sthavira, Vrddha
Bengali: Shailaj
English: Litho Lichen, Rock Moss, Stone Flower, Yellow Lichen
Sanskrit: Silapuspa, Silavalka, Sitasiva
Tamil: Kalpashee
Telugu: Kallu-pachi, Ratipuvvu
Unani: Dowala, Charelaa, Hazaz-al-Sakhr
Urdu: Chhadila, Pariyo, Ushna
French: Parmelia des murs
German: Wandschildflechte
Gujarati: Chhadilo, Ghabilo, Patthar Phool
Hindi: Chhadila, Charela, Chharila, Pathar ka phool
Kannada: Kallu-hoovu, Kallu-huvu, Shilapushpa
Malayalam: Kalppuvu, Sheleyam
Marathi: Dagad phool
Persian: Davala
Punjabi: Ausneh, Chhadila

Habitat

It is commonly found in countries such as India, Sri Lanka and various parts of Southeast Asia, where the humid climate favours its growth.

Morphology

The morphology of Parmelia perlata (now classified as Parmotrema perlatum) is characteristic of foliose lichens, displaying a leafy, loosely attached thallus that can spread widely over the surface it inhabits. The thallus is typically greyish-green to bluish-grey in color, with broad, lobed margins that are often wavy and irregular. The upper surface is smooth and slightly shiny, while the lower surface is usually black with scattered rhizines—root-like structures that help anchor the lichen to its substrate. The margins of the lobes are often lined with cilia (fine hair-like projections), and the thallus frequently exhibits soredia or isidia, which are reproductive structures used for vegetative propagation.

Classical categorisation

According to Bhavprakash Nighantu: Karpooradi Varga
According to Kaiyadeva Nighantu: Dhatu Varga
According to Dhanvantari Nighantu: Chandanadi Varga

Parpatadi Varga

शैलेयं शीतलं हृद्यं कफपित्तहरं लघु |

कण्डुकुष्ठाश्मरीदाहविषहृद गुदरक्तहृत ||(Bhavprakash Nighantu Karpooradi varga 91)

According to the above shloka, Yellow lichen is light, contains cold potency, good for the heart, balances Kapha and Pitta Dosha. It is effective in the management of itching, leprosy, stones, burning sensation, poisoning and bleeding in the anal region.

Ayurvedic properties

Taste (Rasa)- Bitter (Tikta), Astringent (Kashaya)
Physical Property (Guna)- Light (Laghu), Unctuous (Snigdha)
Potency (Veerya)- Cold Potency (Sheet)
Post-digestion Effect (Vipaka)- Katu (Pungent)
Effect on Tridosha- Balance Pitta and Kapha Dosha

Therapeutic properties

Rejuvenative
Anti-inflammatory
Blood-purifier
Tuberculosis
Anti-poisoning
Manage stones
Pacifies burning sensations
Effective in managing blood in anal region
Effective against itching and skin conditions

Systemic actions

External- It is effective in the management of skin disease, burns and pain relief.

Internal use-

Digestive System: Acts as a carminative and absorbent. It is beneficial in conditions like excessive thirst, vomiting, loss of appetite, diarrhoea, and dysentery.
Circulatory System: Possesses cardioprotective properties, supporting heart health.
Respiratory System: Helps eliminate aggravated Kapha dosha and is useful in managing cough and breathing difficulties.
Excretory System: Functions as a diuretic, increasing urine output. It is indicated in urinary disorders such as calculi (Ashmari) and painful urination (dysuria). A decoction of its root, when taken with sugar and cumin powder, is especially effective.
Tapakrama (Fever Management): Manage fever accompanied by a burning sensation.
Skin (Tvak) System: Effective in treating skin conditions characterised by burning sensations.

Chemical composition

Usnic acid
Calcium oxalate
Polysaccharides
Phenolics
Sterols
Volatile oils
Glycosides
Triterpenes

Modern overview

Antidiabetic effect

The aqueous leaf extract of Parmelia perlata, administered at doses of 200 mg/kg and 400 mg/kg body weight for 60 days, demonstrated significant antidiabetic effects in alloxan-induced diabetic rats when compared to glibenclamide. The extract effectively lowered fasting blood glucose and HbA1c levels, enhanced plasma insulin levels and restored the activity of glucose-metabolising enzymes. Additionally, it improved the lipid profile by reducing serum triglycerides, cholesterol, LDL, VLDL, free fatty acids and phospholipids, while increasing HDL levels in a dose-dependent manner.

Antibacterial activity

Methanolic, ethyl acetate and acetone extracts of Parmelia perlata have shown significant antibacterial activity against Staphylococcus aureus, as demonstrated using the Kirby-Bauer disc diffusion and Mueller-Hinton agar plate methods. Additionally, the hydro-alcoholic extract exhibited strong antibacterial effects against Bacillus cereus, Pseudomonas aeruginosa, Proteus vulgaris, Staphylococcus aureus, Corynebacterium xerosis, Escherichia coli and Klebsiella pneumoniae using the agar well diffusion method. This potent antibacterial activity is likely attributed to the presence of usnic acid in the extracts.

Practical uses

For Cough & Cold– Boil a small amount in water and consume it as herbal tea with honey.
For Indigestion – Powder it and mix with warm water or buttermilk after meals to aid digestion.
For Urinary Issues– Decoction of the lichen with sugar and cumin helps relieve dysuria and urinary stones.
For Skin Diseases – Make a paste with water or coconut oil and apply externally on itching or rashes.
For Wound Healing– Apply powdered lichen directly or mixed with turmeric on minor wounds or cuts.
For Fever with Burning Sensation– Prepare a decoction and drink twice daily to reduce heat and discomfort.
For Mouth Ulcers– Use its decoction as a mouth rinse to soothe ulcers and inflammation.

Part used

Whole plant

Dosage

Powder of plant- 2-4 gms

Conclusion

It is a highly significant drug in traditional medicine, known for its wide range of therapeutic properties. While several of these, such as antimicrobial, antidiabetic, antioxidant, antiulcer and hepatoprotective effects, have been scientifically validated, many of its traditional uses, such as analgesic, anti-inflammatory, treatment for male sexual issues, menstrual disorders, blood diseases and heart diseases, remain less explored. Additionally, it contains numerous unique phytoconstituents that may contribute to its pharmacological activities, though many of these are still not fully investigated.