Crotalaria spectabilis
(showy rattlepod)

Pictures

Picture	Title	Caption	Copyright
Title Habit Caption Crotalaria spectabilis (showy rattlepod); flowers and leaves. India. December 2009. Copyright ©Dinesh Valke/via wikipedia - CC BY-SA 2.0	Habit	Crotalaria spectabilis (showy rattlepod); flowers and leaves. India. December 2009.	©Dinesh Valke/via wikipedia - CC BY-SA 2.0
Title Habit Caption Crotalaria spectabilis (showy rattlepod); invasive habit, showing flowers, foliage and seedpods. USA. October 2009. Copyright ©Karan A. Rawlins/University of Georgia/Bugwood.org - CC BY-NC 3.0 US	Habit	Crotalaria spectabilis (showy rattlepod); invasive habit, showing flowers, foliage and seedpods. USA. October 2009.	©Karan A. Rawlins/University of Georgia/Bugwood.org - CC BY-NC 3.0 US
Title Flowers and leaves Caption Crotalaria spectabilis (showy rattlepod); flowers and leaves. India. Decembe 2009. Copyright ©Dinesh Valke/via wikipedia - CC BY-SA 2.0	Flowers and leaves	Crotalaria spectabilis (showy rattlepod); flowers and leaves. India. Decembe 2009.	©Dinesh Valke/via wikipedia - CC BY-SA 2.0
Title Inflorescence Caption Crotalaria spectabilis (showy rattlepod); flowers and leaves. India. December 2009. Copyright ©Dinesh Valke/via wikipedia - CC BY-SA 2.0	Inflorescence	Crotalaria spectabilis (showy rattlepod); flowers and leaves. India. December 2009.	©Dinesh Valke/via wikipedia - CC BY-SA 2.0
Title Flowers Caption Crotalaria spectabilis (showy rattlepod); close view of flowers. USA. Copyright ©John D. Byrd/Mississippi State University/Bugwood.org - CC BY 3.0 US	Flowers	Crotalaria spectabilis (showy rattlepod); close view of flowers. USA.	©John D. Byrd/Mississippi State University/Bugwood.org - CC BY 3.0 US
Title Flowers Caption Crotalaria spectabilis (showy rattlepod); close view of flowers. India. December 2008. Copyright ©Dinesh Valke/via wikipedia - CC BY-SA 2.0	Flowers	Crotalaria spectabilis (showy rattlepod); close view of flowers. India. December 2008.	©Dinesh Valke/via wikipedia - CC BY-SA 2.0
Title Seedpods Caption Crotalaria spectabilis (showy rattlepod); seedpods. India. December 2009. Copyright ©Dinesh Valke/via wikipedia - CC BY-SA 2.0	Seedpods	Crotalaria spectabilis (showy rattlepod); seedpods. India. December 2009.	©Dinesh Valke/via wikipedia - CC BY-SA 2.0
Title Seedpods Caption Crotalaria spectabilis (showy rattlepod); seedpods. USA Copyright ©Wendy VanDyk Evans/Bugwood.org - CC BY-NC 3.0 US	Seedpods	Crotalaria spectabilis (showy rattlepod); seedpods. USA	©Wendy VanDyk Evans/Bugwood.org - CC BY-NC 3.0 US
Title SeedpodS Caption Crotalaria spectabilis (showy rattlepod); close view of seedpods. USA. Copyright ©Johnny N. Dell/Bugwood.org - CC BY-NC 3.0 US	SeedpodS	Crotalaria spectabilis (showy rattlepod); close view of seedpods. USA.	©Johnny N. Dell/Bugwood.org - CC BY-NC 3.0 US

Identity

Preferred Scientific Name

• Crotalaria spectabilis Roth.

Preferred Common Name

• showy rattlepod

Other Scientific Names

• Crotalaria altipes Raf.
• Crotalaria cuneifolia (Forssk.) Schrank
• Crotalaria leschenaultii DC.
• Crotalaria macrophylla Wienmann
• Crotalaria retzii Hitchc.
• Crotalaria sericea RETZ.
• Crotalaria spectabilis subsp. spectabilis

International Common Names

• English: cat's bell; rattlebox; rattlepod; showy crotalaria; showy rattlebox; silent rattlepod
• French: crotalaire remarquable
• Chinese: da tuo ye zhu shi dou

Local Common Names

• Cuba: chicharra ; maromera; maruga
• Dominican Republic: maraquita
• Germany: Ansehliche Klapperhuelse
• India: dhundhunia; jhunjhunia; rattle box; sani; showy crotalaria; sonnette; tcha-tcha
• Thailand: mahing men
• USA: showy rattlebox

EPPO code

• CVTSP (Crotalaria spectabilis)

Summary of Invasiveness

C. spectabilis is native to tropical Asia and has been widely introduced in many tropical countries around the world. It has escaped from cultivation and can now be found naturalized principally in open and disturbed sites. This species is a serious weed in agricultural land and natural habitats (Randall, 2012). The potential invasiveness of C. spectabilis is very high mainly because this species spreads predominantly as a contaminant in agricultural equipment, crop seeds, forages and hay (Maddox et al., 2011). In the United States, it is listed as a noxious weed in many Mid-South states (e.g., Arkansas), and it has spread rapidly throughout the Southeastern states where it is now considered an invasive species (Maddox et al., 2011; USDA-NRCS, 2015). C. spectabilis is also listed as invasive in Cuba, Australia, New Caledonia and many other islands in the Pacific Ocean (Oviedo Prieto et al., 2012; PIER, 2015; Weeds of Australia, 2015).

Taxonomic Tree

• Domain: Eukaryota
•     Kingdom: Plantae
•         Phylum: Spermatophyta
•             Subphylum: Angiospermae
•                 Class: Dicotyledonae
•                     Order: Fabales
•                         Family: Fabaceae
•                             Subfamily: Faboideae
•                                 Genus: Crotalaria
•                                     Species: Crotalaria spectabilis

Notes on Taxonomy and Nomenclature

Fabaceae is one of the most diverse families of flowering plants. Species in the subfamiliy Papilionoideae (also known as Faboideae) are trees, shrubs, and herbs that may be easily recognized by their classical pea-shaped flowers and the frequent occurrence of root nodulation (Stevens, 2012).

The genus Crotalaria includes around 720 species especially distributed in the Southern Hemisphere throughout tropical regions and extending into the subtropics (Roux et al., 2013; Flora of China Editorial Committee, 2015). The name Crotalaria derives from the Greek krotalos for rattle, refering to the sound dried pods make when shaken: the common name for the genus, rattlebox or rattlepod, also refers to the rattling of seeds in the pods after drying.

 A recent molecular systematic study based on nuclear internal transcribed spacer and the plastid markers matK, psbA-trnH and rbcLa showed that Crotalaria is monophyletic (Roux et al., 2013). Crotalaria species are easily recognized by the following combination of characters (Wyk, 2005):

• rostrate keel

• highly inflated fruit

• hairy style

• 5 + 5 anther configuration

• paired callosities on the standard petal

• presence of macrocyclic pyrrolizidine alkaloids

Description

C. spectabilis is an erect herb 0.6-1.5 m tall. Branches terete, glabrous. Stipules ovate-triangular, approximately 1 cm. Leaves simple; petiole 2-8 mm; leaf blade oblanceolate to narrowly elliptic, 7-15 × 2-5 cm, thin, abaxially appressed silky pubescent, adaxially glabrous, base broadly cuneate, apex obtuse and mucronate. Racemes terminal, 20-30-flowered; bracts ovate-triangular, 7-10 mm. Pedicel 1-1.5 cm; bracteoles inserted at or apical to middle of pedicel, linear, approximately 1 mm. Calyx 2-lipped, 1.2-1.5 cm, glabrous; lobes broadly lanceolate-triangular, longer than tube. Corolla pale yellow; standard veined purplish red, suborbicular to oblong, 1-2 cm, base with 2 appendages, apex obtuse to retuse; wings obovate, approximately 2 cm; keel rounded about middle, with a fairly short and slightly incurved twisted beak beyond calyx. Legume broadly oblong, 2.5-3 × 1.5-2 cm, 20-30-seeded, shortly stipitate, glabrous. Seeds smooth, dark brown, 4.5 mm long (Flora of China Editorial Committee, 2015).

Plant Type

Distribution

C. spectabilis is native to tropical Asia (ILDIS, 2015; USDA-ARS, 2015). It is also cultivated and naturalized throughout the tropics (see Distribution Table for details).

Distribution Table

The distribution in this summary table is based on all the information available. When several references are cited, they may give conflicting information on the status. Further details may be available for individual references in the Distribution Table Details section which can be selected by going to Generate Report.

History of Introduction and Spread

C. spectabilis has been widely introduced throughout the tropics to be used as fodder, green manure, for soil conservation, and as a soil improver and ornamental. However, the use of this species has been abandoned because of the toxic alkaloids that it contains (Francis, 2004). In the United States, it was introduced from the Indo-Malaysian area (Maddox et al., 2011). In the West Indies, C. spectabilis appears in herbarium collections made in 1937 in Dominica, in 1939 in Martinique, and in Cuba in 1950 (US National Herbarium).

Risk of Introduction

The risk of introduction of C. spectabilis is high. This species has been actively introduced to be used as green manure, forage and ground cover, and consequently the risk of new introductions as well as the probability of escape from cultivation is high, principally in disturbed areas (Wagner et al., 1999; Maddox et al., 2011; USDA-NRCS, 2015).

Habitat

C. spectabilis grows as a weed in crops, pastures, and roadsides. It prefers sites that are open and disturbed, but as a legume these sites tend to be poor nutritionally. It is often found on roadside or pasture slopes that may be more or less eroded (Maddox et al., 2011). In China, it occurs in open locations along forest margins and as a weed in cultivated fields, from sea level up to 1500 m altitude (Flora of China Editorial Committee, 2015). In the West Indies and Florida, it can be found growing at the edge of mangroves (Liogier, 1988). It is also common along stream banks in deciduous forests in India (Francis, 2004).

Habitat List

Hosts/Species Affected

C. spectabilis is a common weed in maize and soyabean plantations in the United States. It is also a weed in active and abandoned pastures (Maddox et al., 2011).

Biology and Ecology

Genetics

The chromosome number reported for C. spectabilis is 2n = 16 (Almada, 2006).

Reproductive Biology

Flowers of C. spectabilis are visited by bees and other insects. As in other Crotalaria species, extensive cross-pollination occurs and self-pollination only takes place after the stigmatic surface is stimulated by insects or other mechanism (Francis, 2004; Maddox et al., 2011; PROTA, 2015).

Physiology and Phenology

C. spectabilis is an annual fast-growing legume. It may reach heights of about 1 metre by one year old. In Puerto Rico, it behaves as a biennial and plants appear to live 2 or 3 years (Francis, 2004).

In China, C. spectabilis has been recorded flowering from August to October and fruiting from October to December (Flora of China Editorial Committee, 2015). In India, it flowers between November and January and fruits are produced from December to February. In the Americas, it has been recorded blooming all year long in Florida, and flowering in April and May and fruiting in October in Nicaragua (Francis, 2004).

Associations

C. spectabilis has root nodules that support nitrogen fixing bacteria and therefore it is often used as a green manure crop, particularly where rotation for control of nematodes is important (Francis, 2004).

Environmental Requirements

C. spectabilis principally grows in areas from sea level up to 1500 m altitude with annual rainfall of 900-2800 mm and a mean annual temperature of 12-28°C (Niyomdham, 1997). In Florida and Puerto Rico, it grows on coastal sands and limestone rubble in areas receiving about 1650 mm of annual precipitation (Francis, 2004). This species has the capability to thrive on a wide range of soils, including heavy soils, with pH ranging from 4.8 to 8.0 (Niyomdham, 1997). It grows well in alkaline soils and at least tolerates moderate soil salinity. It is also drought-tolerant (Francis, 2004; Maddox et al., 2011; PROTA, 2015).

Climate

Air Temperature

Rainfall

Rainfall Regime

Soil Tolerances

Soil drainage

• free

Soil reaction

• acid
• alkaline
• neutral

Soil texture

• heavy
• light
• medium

Special soil tolerances

• saline
• shallow

Notes on Natural Enemies

In Puerto Rico, plants of C. spectabilis are often parasitized by Cuscuta species (Francis, 2004).

Means of Movement and Dispersal

C. spectabilis spreads by seeds. Seeds are primarily dispersed as a contaminant of soil, agricultural equipment, crop seeds and hay (Maddox et al., 2011). The species is intentionally planted in cultivated lands where is used as a green manure and for erosion control (Niyomdham, 1997).

Pathway Causes

Pathway Vectors

Impact Summary

Economic Impact

Like other Crotalaria species, C. spectabilis contains pyrrolizidine alkaloids, which are present in greatest quantity in the seeds. Therefore, C. spectabilis can be poisonous to all livestock including poultry (chickens, turkeys and quail), horses, goats and dogs, particularly when seeds are consumed (Francis, 2004; Maddox et al., 2011). This species is also a weed negatively impacting maize and soyabean plantations and pastures (Niyomdham, 1997; Francis, 2004; Maddox et al., 2011).

Environmental Impact

C. spectabilis has escaped from cultivation and naturalized in disturbed areas, roadsides, waste ground, grasslands, disturbed forests, and mangrove edges (Liogier, 1988; Wagner et al., 1999; Francis, 2004; Maddox et al., 2011). Once naturalized,this species grows as a weed and may become invasive, displacing native vegetation (ILDIS, 2015; USDA-NRCS, 2015). As with many other Crotalaria species, C. spectabilis is a nitrogen-fixing species and consequently it has the capacity to alter chemical soil conditions, nutrient cycling and trophic levels in invaded ecosystems, with negative effects on native vegetation principally in nutrient-poor ecosystems that did not previously contain nitrogen-fixing residents (Levine et al., 2003).

Risk and Impact Factors

• Proved invasive outside its native range
• Has a broad native range
• Abundant in its native range
• Highly adaptable to different environments
• Is a habitat generalist
• Tolerates, or benefits from, cultivation, browsing pressure, mutilation, fire etc
• Pioneering in disturbed areas
• Highly mobile locally
• Benefits from human association (i.e. it is a human commensal)
• Fast growing
• Has high reproductive potential
• Gregarious

• Altered trophic level
• Damaged ecosystem services
• Ecosystem change/ habitat alteration
• Loss of medicinal resources
• Modification of nutrient regime
• Modification of successional patterns
• Monoculture formation
• Negatively impacts agriculture
• Negatively impacts animal health
• Reduced native biodiversity
• Threat to/ loss of native species

• Competition - monopolizing resources
• Competition - smothering
• Poisoning
• Rapid growth

• Highly likely to be transported internationally accidentally
• Highly likely to be transported internationally deliberately
• Difficult to identify/detect as a commodity contaminant
• Difficult to identify/detect in the field

Uses

C. spectabilis is used as a green manure, for erosion control and for soil improvement in the tropics and in the USA. It serves as a nurse species during early reforestation. Its use as forage and fodder has ceased because of its toxicity. It is also planted as an ornamental (Niyomdham, 1997). This species is also used in Asian traditional medicine. Extracts of the whole plant are used to treat impetigo and scabies, as an antiseptic for cuts, and to treat intestinal worms (Parrotta 2001; Francis, 2004).

Uses List

Environmental

• Agroforestry
• Amenity
• Erosion control or dune stabilization
• Soil conservation
• Soil improvement

Human food and beverage

• Honey/honey flora

Materials

• Green manure
• Poisonous to mammals

Medicinal, pharmaceutical

• Traditional/folklore

Ornamental

• Propagation material

Prevention and Control

Movement Control

Small patches of C. spectabilis can be removed by hand, but it could be labour intensive. Plants should be removed prior to fruit ripening to avoid seed dispersal. In pastures, trimming can be an effective method of weed management to minimize exposure of grazing animals to plants that are toxic. Repeat as necessary to minimize likelihood of consumption by livestock and seed production. Care should be taken to prevent contamination of forages, hay or silage. In grain crops, such as maize or soyabean, care should be taken to avoid contamination of harvested grains with C. spectabilis seed. Sanitation should be used to prevent the movement of seed on tillage or harvest equipment from one field to other fields (Maddox et al., 2011).

Chemical Control

The herbicides suggested for controlling C. spectabilis are diuron, dicamba, hexazinone, triclopyr, flumioxazin, paraquat, glyphosate, and 2,4-D. These herbicides have been used with positive results in pastures and cultivated areas (Maddox et al., 2011).

References

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Almada RD, 2006. Karyotype analysis and chromosome evolution in southernmost South American species of Crotalaria (Leguminosae)., Botanical Journal of the Linnean Society, 150:329-341

Braz GBP, Oliveira Júnior RS de, Constantin J, Takano HK, Godinho FB, 2016. Selectivity of herbicides applied in post-emergence of showy crotalaria., Revista Caatinga, 29(4):918-926

Broome R, Sabir K, Carrington S, 2007. Plants of the Eastern Caribbean. Online database. Barbados: University of the West Indies. http://ecflora.cavehill.uwi.edu/index.htm

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Flores AS, 2015. Crotalaria in Lista de Espécies da Flora do Brasil. Rio de Janeiro, Brazil: Jardim Botânico do Rio de Janeiro. http://floradobrasil.jbrj.gov.br/jabot/floradobrasil/FB82990

Florida Natural Areas Inventory, 2014. Crotalaria spectabilis, Showy rattlebox. http://fnai.org/Invasives/Crotalaria_spectabilis_FNAI.pdf

Francis JK, 2004. Wildland shrubs of the United States and its territories: thamnic descriptions: volume 1. Gen. Tech. Rep. IITF-GTR-26, 1. San Juan, Puerto Rico: US Department of Agriculture, Forest Service, International Institute of Tropical Forestry, and Fort Collins, CO: US Department of Agriculture, Forest Service, Rocky Mountain Research Station, 830 pp. http://www.fs.fed.us/global/iitf/wildland_shrubs.htm

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Levine JM, Vila M, D’Antonio CM, Dukes JS, Grigulis K, Lavorel S, 2003. Mechanisms underlying the impacts of exotic plant invasions., Proceedings of the Royal Society of London. Series B: Biological Sciences, 270:775-781

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Maddox V, Westbrooks R, Byrd JD Jr., 2011. Showy rattlebox. Online resources Mississippi State University, Geosystems Research Institute. https://www.gri.msstate.edu/ipams/FactSheets/Showy_rattlebox.pdf

Niyomdham C, 1997. Crotalaria spectabilis Roth. Record from Proseabase. In: Faridah Hanum I, Maesen LJG van der, Eds. PROSEA (Plant Resources of South-East Asia) Foundation, Bogor, Indonesia. http://www.proseanet.org

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Wyk BE van, 2005. Tribe Crotalarieae. In: Lewis G, Schrire B, Mackinder B, Lock M, eds. Legumes of the World. Kew: Royal Botanic Gardens, pp. 273–281.

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Links to Websites

Contributors

03/05/16 Original text by:

Julissa Rojas-Sandoval, Department of Botany-Smithsonian NMNH, Washington DC, USA

Distribution Maps