Crotalaria retusa is a species of flowering plant in the legume family known by various common names including devil-bean, rattleweed, shack shack, and wedge-leaf rattlepod It is poisonous to livestock, and contaminates human food. Its original native range is unclear, probably including tropical Asia, Africa and Australia. It has been introduced as a crop plant in many tropical areas and has escaped from cultivation to become a troublesome weed; it is listed as a noxious weed in several US states, Puerto Rico, the Virgin Islands, and is listed as an invasive weed in India, Cuba, and Cocos Island.Unlike some other species of Crotalaria, it is an annual plant.
HISTORICAL AND MYTHOLOGICAL REVIEW:
Several Crotalaria species were introduced from Asia into tropical regions in the Western Hemisphere early in the nineteenth century (Sheahan, 2012; USDA-NRCS, 2013). In the West Indies C. retusa was first reported in 1876 in the Virgin Islands (Eggers, 1876). By 1900, this species is listed as a “common herb” in the United States, Mexico, Central America, Brazil, Bahamas, Cuba, Jamaica, Hispaniola, Puerto Rico, Virgin Islands, St Kitts, Guadeloupe, Dominica, Martinique, Netherland Antilles, St Vincent, Barbados, Grenada, and Trinidad and Tobago (Urban, 1905; Orwa et al., 2009).
Crotalaria retusa is grown as a fibre crop and as green manure. It is also used as a forage plant, but is poisonous to livestock.
Plants in this genus generally prefer a sunny position, succeeding in dry to moist, well-drained soils
Grown as a green manure, fibre crop and ornamental, the plant has escaped from cultivation and become naturalized in some areas. It is considered to be invasive in some areas - in Hawaii, for example, it is naturalized in disturbed sites such as roadsides, dump sites and urban areas
The plant can flower and produce fruit all year round
This species has a symbiotic relationship with certain soil bacteria, these bacteria form nodules on the roots and fix atmospheric nitrogen. Some of this nitrogen is utilized by the growing plant but some can also be used by other plants growing nearby
Seed - sow in situ. Pre-soaking the seed for 12 hours in warm water can help to reduce germination time.
Seeds should be collected from mature pods that were allowed to dry on the plant. Sow seeds immediately, because they quickly lose viability.
Study of seeds yielded proximate values of moisture 15.00, fiber 37.50, ash 15.00, crude protein 4.37, oil 15.00, and carbohydrates 13.13%.
- Study isolated a pyrrolizidine alkaloid, monocrotaline.
- Phytochemical screening of leaf, stem, seed, pods and flowers yielded saponins, tannins, alkaloids, and sterols. Leaf showed highest concentration of phenols (67.35 ± 1.153 mg GAE/g of extract).
- Phytochemical screening of crude extract of leaves yielded alkaloid++, steroid++. flavonoid+, tannin+, reducing sugar++, with an absence of saponin and phenol.
Parts used for medicinal purpose
Whole plant, ,
Supportive treatment. Early diagnosis and avoidance of further exposure to the toxins is important
Crotalaria pallida Aiton-Fabacae
1.Crotalaria junica Linn-Fabacae
2.Crotalaria verrucosa Linn-Fabacae
Crotalaria retusa is a butterfly host plant. According to the Butterfly Circle website, Crotalaria retusa is the food plant for the pea blue butterfly (Lampides boeticus). Unlike other butterfly caterpillars that chew up leaves, the first two instars of the pea blue bore into flower buds of this plant and consume the flower parts contained within. The larger 3rd and final instar caterpillars will move on to eat the developing seeds within seed pods.
C. retusa has been actively introduced to be used as a fibre crop, green manure, forage, ground cover and soil improver, and consequently the risk of new introductions as well as the probability of escape from cultivation is high, mainly in disturbed areas (Wagner et al., 1999; Brunner et al., 2013; PIER, 2013).
Erect annual or short-lived perennial, 0.5–1.5 m tall, usually well branched; branches slightly ribbed, subdensely covered with short hairs.
Leaves simple; blade 3.5–11 × 1.5–4 cm, oblanceolate to oblong-obovate, finely appressed pubescent beneath; petiole c. 2–4 mm long; stipules 1–5 mm long, linear or subulate.
Racemes 10–30 cm long, many-flowered; bracts c. 2–6 mm long, subulate-caudate to lanceolate-caudate; bracteoles on the pedicel, 1–2 mm long, filiform.
Calyx 1.1–1.4 cm long, glabrous to appressed puberulous; upper lobes broadly lanceolate-triangular, longer than the tube.
Standard obovate-circular, pale yellow, veined and outside often suffused reddish-purple, usually puberulous along the midvein outside; wings oblong-obovate, longer than the keel, bright yellow; keel 1.3–1.5 cm long, rounded, with a fairly short slightly incurved twisted beak.
Pod shortly stipitate, (3)4–5 × 1–1.8 cm, oblong-clavate, glabrous, c. 12–20-seeded.
Seeds c. 5–5.5 mm long, oblique-cordiform, with the narrow end strongly incurved, finely papillose, yellowish or brown.
Widespread in both the forest and savanna zones of West Africa.
In Australia, where it is considered a native, it grows in the Kimberley on sand, clay, sandstone, and rocky basaltic soils, and is found along creeks and rivers, and on the floodplains
Coastal grassland, along rivers, waste places and fields, at elevations up to 250 metres. Open places in deciduous dipterocarp forests; at elevations up to 1,500 metres
Local Conservation Status :
Exotic (Horticultural / Cultivated Only)
Conservation status - Least Concerned
Seeds contain basic alkaloid with N-oxides in their leaves and are used in ethno-medicine for the treatment of fever, as vermifuge and as an antispasmodic (uterus & intestine) agent. Also seeds powdered & boiled with milk are used for enhancing body strength, life span and also for curing skin diseases, leprosy, flatulence and fever. The leaves are the excellent remedy for Ptyalism, Diarrhoea, Scabies and Impetigo (Devendra et al., 2011).
The plant is used as a treatment for complaints such as cough, dyspepsia, fever, cardiac disorders, stomatitis, diarrhoea, scabies and impetigo
An infusion of the plant is used to bathe children in order to prevent skin infections and also to treat thrush
The leaves, mixed with those of Crotalaria quinquefolia, act internally as well as externally against fever, scabies, lung diseases and impetigo
A decoction of the flowers and leaves is used to soothe a cold
The seeds are eaten raw to act as an analgesic to deaden the pain of a scorpion sting. The powdered seeds, mixed with milk, are eaten in order to increase body strength; they are also used to treat skin diseases
The plant contains hepatotoxic pyrrolizidine alkaloids
1. Analysis of pyrrolizidine alkaloid from Crotalaria retusa L / Srinivas Nakka, Bapatla Veerendra Kumar and Bellary Nagaraju Devendra / Der Pharma Chemica, 2013, 5(6):6-11
2. Preliminary Antimicrobial Screening of Some Indian Medicinal Plants Part I / P. Malairajana*, Geetha Gopalakrishnanb, S. Narasimhanc and K. Jessi Kala Venia / Int. J. Drug Dev. & Res., October-December 2012, 4(4): 133-137
3. The role of astrocytes in metabolism and neurotoxicity of the pyrrolizidine alkaloid monocrotaline, the main toxin of Crotalaria retusa / Bruno Penas Seara Pitanga, Ravena P. Nascimento, Victor Diógenes A. Silva and Silvia L. Costa*/ Front. Pharmacol., 03 August 2012 | doi: 10.3389/fphar.2012.00144
4. Monocrotaline: Histological Damage and Oxidant Activity in Brain Areas of Mice / Jose ́ Eduardo Ribeiro Hono ́ rio Junior, Germana Silva Vasconcelos, Francisca Taciana Sousa Rodrigues, Jose ́ Guedes Sena Filho, Jose ́ Maria Barbosa-Filho, Carlos Clayton Torres Aguiar, Luzia Kalyne Almeida Moreira Leal, Pedro Marcos Gomes Soares, David John Woods, Marta Maria de França Fonteles, and Silvaˆnia Maria Mendes Vasconcelos / Oxidative Medicine and Cellular Longevity Volume 2012 / doi:10.1155/2012/697541)
1. Clastogenic effect of extracts obtained from Crotalaria retusa L. and Crotalaria mucronata Desv. on mouse bone marrow cells / Lucia R Robeiro, Ana Rita Silva, Ana Rita P L Bautista et al / Mutation Research/Genetic Toxicology, Vol 300, No 3-4, August 1993, Pages 253-258 / doi:10.1016/0165-1218(93)90058-L
The plant is reported to yield toxins, such as the pyrrolizidine alkaloid monocrotaline, and is said to have poisoned poultry and livestock in Nigeria Many members of this genus are known to contain pyrrolizidine alkaloids, the most potent of which in this genus are monocrotaline, retrorsine and retronecine. These alkaloids have a cumulative effect upon the body and, unless concentrations in a plant are high, occasional consumption is generally completely safe. Pyrrolizidine alkaloids are derived from amino acids including ornithine. Many of these alkaloids have pronounced hepatic toxicity, but the lungs and other organs may be affected as well. Mutagenic and carcinogenic activities of pyrrolizidine alkaloids have also been reported
Use in other system of medicine:
- Flowers and leaves reportedly eaten as vegetable.
- In Vietnam, seeds are roasted and eaten.
- No reported folkloric medicinal use in the Philippines.
- In Ayurveda, plant vitiated kapha, vata, cough, dyspepsia, fever.
- Powdered seeds mixed with milk used for increasing body strength; also used for skin diseases.
- In Cameroon, plant used in the treatment of eczema.
- In Tamil Nadu, India, plant used for cough, dyspepsia, fever, cardiac disorders, stomatitis, diarrhea, scabies, impetigo.
- In Zaria, northern Nigeria, powdered plant mixed with roasted black caraway, taken in small quantities for stomach coli and flatulence. Squashed flowers with added potash, cooked into a soup, and taken for amenorrhea. For scabies, decoction of whole plant used for bathing.
- Roots used for hemoptysis.
- Leaves mixed with those of Crotalaria quinquefolia, consumed or applied externally for fever, scabies, lung afflictions, and impetigo.
- In Bangladesh, tribal people in the Chittagong Hill tracts use fresh juice and paste of leaves and seeds for skin diseases.
- In India, seeds used for skin infection, constipation and pain.
- Fiber: Bark and stems are sources of strong fiber; used for cordage and making canvas.
- Dye: In East Africa, used as dye plant.
- Oil: Seed yields a non-edible, non-dryiing oil, with potential for use in making shampoo, creams, and shoe polish.
- Livestock hazard: Poses a potential hazard to livestock because of pyrrolizidine alkaloid content.
Crotalaria retusa is an erect, annual plant or short-lived perennial with more or less woody stems. It can grow from 60 - 120cm tall
The plant is harvested from the wild for local use as a food, medicine and source of materials. It is sometimes cultivated for the fibre it provides, as a medicinal plant, and is also grown as a green manure crop
It is occasionally grown purely as an ornamental, though it is also sometimes considered to be a weed