Cynodon dactylon, commonly known as Bermuda grass or as couch grass in Australia and New Zealand, is a grass found worldwide. It is native to Europe, Africa, Australia, and much of Asia and has been introduced to the Americas.[1] [2]
Contrary to its common name, Cynodon dactylon is not native to Bermuda but is an abundant invasive species there. In Bermuda, it has been known as crabgrass, also a name for Digitaria sanguinalis. Other names include dhoob, dūrvā grass, ethana grass, dubo, dog grass, dog's tooth grass,[3] Bahama grass, devil's grass, couch grass, Indian doab, arugampul, grama, wiregrass, and scutch grass.
Hybrid species of the grass are taxonomically known as Cynodon dactylon × transvaalensis. These interspecific hybrids are the result of cross-pollination between different cultivars. Hybrid cultivars of the grass are commonly developed by selecting individual plants with desirable traits from seeded or vegetatively propagated stands.[4] These cultivars are typically triploids, meaning they contain three sets of chromosomes.[5]
The blades are grey-green in color and short, usually 2cm–15cmcm (01inches–06inchescm) long with rough edges.[6] The erect stems can grow 1cm–30cmcm (00inches–10inchescm) tall. The stems are slightly flattened, often white or green, and occasionally tinged purple in colour.
The seed heads are produced in a cluster of two to six spikes together at the top of the stem, each spike 2cm–5cmcm (01inches–02inchescm) long.
Cynodon dactylon has a deep root system. When grown in penetrable soil under drought conditions, its roots can grow to over 2m (07feet) deep, though most of the root mass is less than 60cm (20inches) under the surface. The grass creeps along the ground with its stolons and roots wherever a node touches the ground, forming a dense mat. C. dactylon reproduces through seeds, stolons, and rhizomes.
The grass starts actively growing at temperatures above 15°C with ideal growth between 24C37C; in winter or in the dry season, the grass becomes dormant and turns light brown. Optimal development also occurs in areas of full sun exposure, while dense shade, especially near tree bases, generally suppresses it.
Cynodon dactylon is widely cultivated in warm climates all over the world between about 30° S and 30° N latitude, and in regions that receive between 625and of rainfall a year, or less, if irrigation is available. For example, in the United States, it is grown mostly in the southern half of the country.
Hundreds of cultivars have been created specifically for environmental tolerance and stakeholder requirements. New cultivars are released annually.[7] [8]
Commonly known as durva or dūrvāyugma in India, this grass is used in the Ayurveda system of medicine. Performing a rite called "the consecration of Rudra (Sanskrit Rudrabhisheka)" described in the Purāṇas while offering durva 11 times bestows long life.
In Hinduism, it is considered important in the worship of Lord Ganesha.[9] [10] A clump of 21 shoots of this grass is usually offered during puja (worship). It has been a part of Hindu rituals since Vedic times. A unique festival called Durga Ashtami, dedicated to this grass, is celebrated on the eighth day of the Navratri festival.[11]
It is known as arugampull in Tamil, garikēhullu in Kannada and karuka in Malayalam, and is part of the Dashapushpam (ten sacred flowers) in Kerala.[12]
In Nepal, the grass is known as dubo and is used by the Hindus. According to Nepalese Hindus, the grass symbolizes long life. The grass is an essential item for the Naga Panchami festival as well as the Gaura festival.[13] [14] [15] In a Nepalese Hindu wedding, a garland made of this grass is worn by both bride and groom.[16]
This grass is a Yoruba herb used for Esu or Elegba in the Ifá system of orishas.
The rhizomes are reported to act as a diuretic in humans, and the grass juice can act as an astringent.[17]
It has been observed that Cynodon dactylon may be selectively eaten by dogs to swiftly induce vomiting when they have gastrointestinal problems. The effect may be due to irritation caused by bristles on the leaf margin.
Bermuda grass is fast-growing and tough, making it a popular choice for sports fields because it will recover quickly when damaged. It is a highly desirable turfgrass in warm temperate climates, particularly in hot and dry regions where it will survive while other grass species cannot.
The combination of heat and drought tolerance makes Bermuda grass a frequent choice for golf courses in the southern and southeastern United States and South Africa. Bermuda grass is also commonly used for football and baseball fields. It has a relatively coarse-bladed form with numerous cultivars selected for different turf requirements.
Bermuda grass has been cultivated in saline soils in California's Central Valley, which are too salt-damaged to support agricultural crops; it was successfully irrigated with saline water and used to graze cattle.[18] [19]
Bermuda grass can be a highly aggressive invasive species, crowding out most other grasses and invading other habitats, and has become a hard-to-eradicate weed in some areas. It can be controlled somewhat with triclopyr, mesotrione, fluazifop-p-butyl, and glyphosate.[20] [21]
This weedy nature leads some gardeners to give it the name of devil grass. Bermuda grass is incredibly difficult to control in flower beds, and most herbicides do not work. However, Ornamec, Ornamec 170, Turflon ester (tricyclopyr), and Imazapyr have shown some effectiveness. All of these items are difficult to find in retail stores, as they are primarily marketed to professional landscapers.[22]
The hybrid variety Tifton 85, like some other grasses (e.g. sorghum), produces cyanide under certain conditions,[23] and has been implicated in several livestock deaths.
