Asiatic pennywort (Centella asiatica) is a perennial herb that creeps along the ground. It is a common turf weed that reproduces by seeds and spreads aggressively by rhizomes underground. It features kidney-shaped leaves that are soft and tender. It is native to India and grows in shade with adequate moisture.
I. Appearance and CharacteristicsÂ
Centella asiatica, commonly known as Indian pennywort, Asiatic pennywort, spadeleaf, coinwort or gotu kola, is a herbaceous, perennial plant in the flowering plant family Apiaceae. It is native to tropical regions of Africa, Asia, Australia, and islands in the western Pacific Ocean.
Centella grows in temperate and tropical swampy areas in many regions of the world. The stems are slender, creeping stolons, green to reddish-green in color, connecting plants to each other. It has long-stalked, green, rounded apices which have smooth texture with palmately netted veins. The leaves are borne on pericladial petioles, around 2 cm (0.79 in). The rootstock consists of rhizomes, growing vertically down. They are cream in color and covered with root hairs.
The flowers are white or crimson in color, born in small, rounded bunches (umbels) near the surface of the soil. Each flower is partly enclosed in two green bracts. The hermaphrodite flowers are minute in size, less than 3 mm (0.12 in), with five to six corolla lobes per flower. Each flower bears five stamens and two styles. The fruit are densely reticulate, distinguishing it from species of Hydrocotyle which have smooth, ribbed or warty fruit. The crop matures in three months, and the whole plant, including the roots, is harvested manually. It is a highly invasive plant, rated as “high risk”. Centella has numerous common names in its regions of distribution.
Because the plant is aquatic, it is especially sensitive to biological and chemical pollutants in the water, which may be absorbed into the plant. It can be cultivated in drier soils, including sandy loam, as long as they are watered regularly enough (such as in a home garden arrangement).
Centella contains pentacyclic triterpenoids and trisaccharide derivatives, including asiaticoside, brahmoside, asiatic acid, and brahmic acid (madecassic acid). Other constituents include centellose, centelloside, and madecassoside. Approximately 124 chemical compounds have been isolated and identified from Centella asiatica. Long term use on the skin can cause severe health problems including: skin irritation, intoxicated blood, red eyes and problems with the lymph nodes.
II. How to Grow and Care
Asiatic pennywort is a hardy perennial herb that thrives in moist, well-drained soil and partial shade, making it generally easy to care for. Special care points include ensuring consistent moisture without waterlogging and providing protection from intense afternoon sun to prevent leaf scorch. Regular watering and occasional fertilization contribute to the robust health of asiatic pennywort.
Sunlight
Asiatic pennywort thrives under partial sun conditions, which means it prefers a mix of sunlight and shade throughout the day. This balance ensures that asiatic pennywort receives enough light for photosynthesis while avoiding the stress of intense midday sun. Asiatic pennywort is adaptable and can tolerate full sun exposure, but prolonged periods in such conditions can lead to leaf burn and reduced growth.
Outdoors, asiatic pennywort should be positioned where it will be protected during the peak sun hours, such as under the dappled light of trees. When receiving optimal light, asiatic pennywort displays robust health, evidenced by lush, vibrant foliage. Deviations from this can result in stunted growth and potential loss of medicinal potency for which the plant is renowned.
Watering
Originating from the damp, marshy areas of Asia, asiatic pennywort thrives in consistently moist environments and exhibits a strong preference for high humidity. This species is moderately drought-tolerant but flourishes when maintained with a balanced moisture regime, ideally receiving water twice a week. As an herb commonly grown outdoors, asiatic pennywort benefits significantly from natural rainfall patterns, which contribute to its lush growth and potent medicinal properties.
Soil
Asiatic pennywort requires well-draining soil. A mix of potting soil, perlite, and organic compost in equal parts ensures good aeration. If perlite is unavailable, sand can substitute. Ensure the mix is loose to prevent water-logging. Incorporate slow-release fertilizers or a balanced liquid fertilizer monthly during the growing season for optimal growth.
Fertilizing
Asiatic pennywort thrives with regular fertilizing, responding well to balanced, water-soluble nutrients. For optimal growth, apply a diluted solution every 4-6 weeks during active growing periods, spring through early fall. A lighter application in the cold season supports asiatic pennywort without overfeeding. Be cautious not to over-fertilize, as asiatic pennywort is sensitive to salt buildup. Use quarter-strength doses for young asiatic pennywort or when in recovery. Regular fertilization encourages lush foliage and contributes to asiatic pennywort’s adaptability and resilience. Always water asiatic pennywort thoroughly post-fertilization to prevent root burn and distribute nutrients evenly.
Propagation
Native to wetlands in Asia, asiatic pennywort is known for its medicinal properties and ground-cover applications. Propagation of asiatic pennywort is most successful through division, a straightforward method where the root clump is segmented into smaller parts. This technique ensures each division has both roots and shoots for optimal growth. Gardeners should take care to maintain adequate soil moisture and protect the young divisions from harsh sunlight to encourage establishment. With its rapid growth habit, asiatic pennywort quickly forms dense mats, making it a suitable choice for beginners looking to add this therapeutic herb to their garden.
Transplanting
Transplanting Time: Mid spring, Late spring, Early summer
Transplant asiatic pennywort during the temperate embrace of late spring to early summer, leveraging vigorous growth conditions. Choose well-draining, moist sites with dappled sunlight. For optimal establishment, ensure soil richness and consistent moisture.
Repotting
Repot asiatic pennywort every 2-3 years to accommodate its mat-forming spread as a ground cover. Choose spring for repotting to support active growth. Select a wide, shallow pot as asiatic pennywort has a shallow root system. Ensure the pot provides ample space for expansion. Aftercare includes maintaining soil moisture without waterlogging and partial shade placement for recovery. An ideal balance will ensure vigorous growth post-repotting.
III. Uses and BenefitsÂ
- Agricultural use
In the context of phytoremediation, C. asiatica is a potential phytoextraction tool owing to its ability to take up and translocate metals from root to shoot when grown in soils contaminated by heavy metals.
- Medicinal uses
In traditional medicine, C. asiatica has been used to treat various disorders, dermatological conditions, and minor wounds, although clinical efficacy and safety have not been scientifically confirmed. Contact dermatitis and skin irritation can result from topical application. Drowsiness may occur after consuming it. Three cases of adverse effects on liver function have been reported on Drugs.com with C. asiatica administration for 20 to 60 days.
- Culinary uses
In Burmese cuisine, raw pennywort is used as the main constituent in a salad mixed with onions, crushed peanuts, bean powder and seasoned with lime juice and fish sauce. Centella is used as a leafy green in Sri Lankan cuisine, being the predominantly locally available leafy green, where it is called gotu kola or vallaarai.
It is most often prepared as malluma, a traditional accompaniment to rice and vegetarian dishes, such as dal, and jackfruit or pumpkin curry. It is considered nutritious. In addition to finely chopped gotu kola plants, the gotu kola malluma may be eaten with grated coconut, diced shallots, lime (or lemon) juice, and sea salt.
Additional ingredients are finely chopped green chilis, chili powder, turmeric powder, or chopped carrots. The Centella fruit-bearing structures are discarded from the gotu kola malluma due to their intense bitter taste. A variation of porridge known as kola kanda is also made with gotu kola in Sri Lanka. Gotu kola kanda or Vallaarai kanji is made with well-boiled red rice with some extra liquid, coconut milk first extract, and gotu kola purée. The porridge is accompanied with jaggery for sweetness.
Centella leaves are also used in modern sweet pennywort drinks and herbal teas. In addition the leaves are served stir-fried whole in coconut oil, or cooked in coconut milk with garlic or dhal.
In Indonesia, the leaves are used for sambai oi peuga-ga, an Aceh type of salad, and is also mixed into asinan in Bogor. In Cambodia, Vietnam and Thailand, this leaf is used for preparing a drink or can be eaten in raw form in salads or cold rolls. In Bangkok, vendors in the Chatuchak Weekend Market sell it alongside coconut, roselle, chrysanthemum, orange and other health drinks.
In Malay cuisine it is known as pegaga, and the leaves of this plant are used for ulam, a type of vegetable salad. C. asiatica is widely used in various Indian regional cuisines. In Bangladesh and India (specifically in West Bengal), Centella is called Thankuni Pata and used in various dishes, one of the most appetising of which is the pakora-like snack called Thankuni Patar Bora; made of mashed Centella, lentils, julienned onion and green chilli.
- Telomerase activation
C. asiatica has been shown to activate telomerase more than any other known compound yet discovered: 8.8-fold. This exceeds the activation by other known telomerase activators: oleanolic acid 5.9-fold, Astragalus extract 4.3-fold, TA-65 2.2-fold, and maslinic acid 2-fold.
