Urochloa reptans
(sprawling signalgrass)

Pictures

Identity

Preferred Scientific Name

• Urochloa reptans (L.) Stapf

Preferred Common Name

• sprawling signalgrass

Other Scientific Names

• Brachiaria balansae Henrard
• Brachiaria prostrata (Lam.) Griseb.
• Brachiaria reptans (L.) C.A.Gardner & C.E.Hubb.
• Digitaria umbrosa (Retz.) Pers.
• Echinochloa reptans (L.) Roberty
• Echinochloa subcordata Roem. & Schult.
• Panicum aurelianum Hale ex Alph.Wood
• Panicum barbipedum Hayata
• Panicum brachythyrsum Peter
• Panicum caespitosum Sw.
• Panicum calaccanzense Steud.
• Panicum extensum Desv.
• Panicum grossarium L.
• Panicum insularum Steud.
• Panicum luxurians Willd. ex Nees
• Panicum nilagiricum Steud.
• Panicum parvum Buse
• Panicum prostratum Lam.
• Panicum reptans L.
• Panicum subcordatum (Roem. & Schult.) Roth
• Panicum taitense Steud
• Panicum umbrosum Retz.
• Setaria subcordata (Roem. & Schult.) Kunth
• Setaria umbrosa (Retz.) P.Beauv.

International Common Names

• English: creeping-panic grass; running grass; sprawling panicum
• Spanish: alpiste de la tierra; cohitrillo; zacate cuero de conejo
• French: chiendent blanc
• Chinese: wei fu cao
• Portuguese: capim-rasteiro

Local Common Names

• Egypt: nissiela
• India: mamakihoho; para grass
• Puerto Rico: yerbita de pichones

EPPO code

• PANRP (Panicum reptans)

Summary of Invasiveness

Urochloa reptans is an annual grass regarded as native to Asia, the Arabian Peninsula, Australia and the Pacific region, although its status is ambiguous in many countries. The species grows forming clumps of slender, creeping culms up to 50 cm tall that are capable of displacing other plants and grasses. It is considered an important weed in agricultural lands and pastures, but it can also invade disturbed sites, degraded forests, coastal areas, river and creek beds, and riparian forests. Currently, it is listed as invasive in Costa Rica, Puerto Rico, the United States Virgin Islands and some islands in Oceania, where it has been reported invading relatively undisturbed forests.

Taxonomic Tree

• Domain: Eukaryota
•     Kingdom: Plantae
•         Phylum: Spermatophyta
•             Subphylum: Angiospermae
•                 Class: Monocotyledonae
•                     Order: Cyperales
•                         Family: Poaceae
•                             Genus: Urochloa
•                                 Species: Urochloa reptans

Notes on Taxonomy and Nomenclature

Poaceae is one of the largest families of Angiosperms and includes about 707 genera and 11,337 species widely distributed in all regions of the world. The genus Urochloa is classified within the tribe Paniceae, subtribe Melinidinae, in the subfamily Panicoideae, and comprises about 110-135 species distributed in tropical and subtropical regions of the world (Salariato et al., 2010; Stevens, 2017). About 20% of the species are native to America, 11% from Oceania and the rest are widely distributed in Africa and Asia. Urochloa shares several morphological, anatomical and physiological characters with the genus Brachiaria and, as a consequence, the delimitation of these two genera has always been complicated. Phylogenetic studies of Urochloa have also been unsuccessful in delimiting this genus and its phylogenetic relationships with other genera (Simon and Jacobs, 2003; Torres González and Morton, 2005; Salariato et al., 2009; 2010). Consequently, the circumscription of Brachiaria and Urochloa will remain uncertain until broader studies are carried out. Should the two be regarded as the same, Urochloa has nomenclatural priority.

Description

Annual grass. Culms slender, creeping, rooting at lower nodes, ascending to 10-50 cm tall. Leaf sheaths glabrous, one margin densely ciliate; leaf blades lanceolate, 2-6 × 0.3-1.2 cm, glabrous or loosely hispidulous, base subcordate, margins scabrous, pectinate-ciliate at base; ligule c. 1 mm, ciliate. Inflorescence pyramidal, axis 1-8 cm; racemes 3-6(-12), 0.5-4 cm, spreading; rachis triquetrous, scabrous; spikelets paired, crowded, pedicels setose. Spikelets ovate or ovate-elliptic, 2-2.5 mm, usually glabrous, acute; lower glume cufflike, 1/8-1/4 spikelet length, thinly membranous, veinless or obscurely 3-veined, truncate or rounded; upper glume (5-)7-9-veined; lower lemma 5-veined, palea well developed; upper lemma broadly elliptic, 1.8-2 mm, finely rugose, apiculate (Flora of China Editorial Committee, 2018).

Plant Type

Distribution

U. reptans is considered native to the Old World, but its exact native range is still unclear. Currently, the species is regarded as native to tropical and temperate Asia, the Arabian Peninsula, Australia and the Pacific region (Clayton et al., 2018; USDA-ARS, 2018). The status of U. reptans on many islands across the Pacific Ocean and some African countries is still ambiguous and thus listed as both native and introduced. This species can be found naturalized in North, Central and South America and in the Caribbean (Acevedo-Rodríguez and Strong, 2012; Clayton et al., 2018; GRIIS, 2018; PIER, 2018). It is recorded as invasive in Costa Rica, Puerto Rico, the United States Virgin Islands, Fiji, French Polynesia, Guam and New Caledonia (Chacón and Saborío, 2012; Florence et al., 2013; Rojas-Sandoval and Acevedo-Rodríguez, 2015; PIER, 2018).

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

In Puerto Rico, U. reptans was introduced as “experimental forage” and was first collected in the wild in 1880 (Más and García-Molinari, 2006; Rojas-Sandoval and Acevedo-Rodríguez, 2015).

Risk of Introduction

The risk of new introductions of U. reptans is moderate, as this species is not a preferred grass for forage. However, it often grows as a weed in agricultural lands and pastures, and thus can be unintentionally dispersed as a contaminant in agricultural produce.

Habitat

U. reptans grows as a weed in cultivated lands, pastures, waste grounds, lawns, gardens, old clearings, and along roadsides, ditches and irrigation channels. It can also be found in moist grassy places, coastal thickets, degraded forests, grasslands, hills, savannahs, river and creek beds, at elevations ranging from sea level up to 1500 m (Hammel et al., 2003; Sánchez-Ken, 2011; Gupta, 2013; Ibrahim et al., 2016; Flora of China Editorial Committee, 2018).

Habitat List

Hosts/Species Affected

U. reptans is considered a weed of soybean, cotton, maize, rice, sugarcane fields and active pastures (including heavily-grazed pastures). It also grows as a weed of gardens and lawns (Tiwari and Kurchania, 1990; Auld and Kim, 1996; Gupta, 2013; PIER, 2018).

Host Plants and Other Plants Affected

Growth Stages

Biology and Ecology

Genetics

The chromosome number reported for U. reptans is 2n = 14, 18 (Flora of China Editorial Committee, 2018).

Reproductive Biology

Urochloa species have hermaphrodite florets. Plants produce seeds asexually by facultative apomixis and sexually by outcrossing (Watson et al., 1992; Veldkamp, 1996).

Physiology and Phenology

U. reptans is an annual grass (Hammel et al., 2003). In China, it has been reported producing flowers and fruits during the summer–autumn, while in India it flowers and fruits from July to November (Flora of China Editorial Committee, 2018; India Biodiversity Portal, 2018). In Costa Rica and Pakistan it produces flowers and fruits from June to October (Hammel et al., 2003; Flora of Pakistan, 2018). 

Environmental Requirements

U. reptans prefers to grow in moist sites in tropical and subtropical habitats, at elevations ranging from sea level to about 1500 m. It grows best in well-drained sandy and loamy soils (Hammel et al., 2003; Más and García-Molinari, 2006; India Biodiversity Portal, 2018).

Climate

Latitude/Altitude Ranges

Air Temperature

Rainfall

Rainfall Regime

Soil Tolerances

Soil drainage

• free

Soil reaction

• neutral

Soil texture

• light
• medium

Natural enemies

Notes on Natural Enemies

U. reptans is a host of the nematode species Meloidogyne incognita (Mahmood, 1988).

Means of Movement and Dispersal

U. reptans spreads by seed. Seeds can be dispersed by wind, water and animals, and as contaminants in machinery and agricultural products (Más and García-Molinari, 2006; India Biodiversity Portal, 2018; PIER, 2018; USDA-ARS, 2018).

Pathway Causes

Pathway Vectors

Environmental Impact

U. reptans is a weed of cultivated lands and pastures. It also hosts the nematode Meloidogyne incognita, which has negative impacts on crops (Mahmood, 1988). U. reptans is also an environmental weed in degraded grasslands and thickets, forest margins and secondary forests, but also in relatively undisturbed forests and riparian areas (Hammel et al., 2003; Sánchez-Ken, 2011; Gupta, 2013; Ibrahim et al., 2016; AusGrass2, 2018; Flora of China Editorial Committee, 2018).

Risk and Impact Factors

• Invasive in its native range
• 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
• Tolerant of shade
• Highly mobile locally
• Benefits from human association (i.e. it is a human commensal)
• Fast growing
• Gregarious

• Ecosystem change/ habitat alteration
• Monoculture formation
• Negatively impacts agriculture
• Reduced native biodiversity
• Threat to/ loss of native species

• Competition - monopolizing resources
• Pest and disease transmission
• 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

Social Benefit

U. reptans is sometimes used as fodder and its grain has been used as food in times of famine (Flora of Pakistan, 2018). Its rhizomes are diuretic and used to treat kidney problems (Gupta, 2013).

Uses List

Animal feed, fodder, forage

• Forage

Human food and beverage

• Emergency (famine) food

Medicinal, pharmaceutical

• Traditional/folklore

Similarities to Other Species/Conditions

U. reptans is described as a borderline species in the genus because its small, plump spikelets are reminiscent of Brachiaria, a genus in which it is placed by some authors (Flora of China Editorial Committee, 2018).

Prevention and Control

Control

Physical/mechanical control

Small infestations of U. reptans can be removed manually or with mulch machinery.

Chemical control

Herbicides such as nicosulfuron, rimsulfuron 2,4-Dichlorophenoxyacetic acid, dicamba and atrazine have been used to control U. reptans in cultivation (Aguilar Carpio et al., 2004).

References

Acevedo-Rodríguez P, Strong MT, 2012. Catalogue of the Seed Plants of the West Indies. Smithsonian Contributions to Botany, 98. Washington DC, USA: Smithsonian Institution.1-1192.

Aguilar Carpio, C., Aguilar Mariscal, I., Michel Aceves, A. C., 2004. Postemergence control of weeds in maize and its cost effectiveness in Guerrero. (Control post emergente de malezas en maíz y su rentabilidad economica en Guerrero). In: Memoria XVI Congreso Latinoamericano de Malezas y XXIV Congreso Nacional de la Asociación Mexicana de la Ciencia de la Maleza, Manzanillo, Colima, México, del 10 al 12 de Noviembre de 2003, [ed. by Pedrero, G. M., Valenzuela, J. A. D., Díaz, G. M., Ruiz, R. A. O.]. Wimauma, USA: Asociación Latinoamericana de Malezas. 72-82.

Auld, B. A., Kim, K. U., 1996. Weed management in rice, 285 pp.

AusGrass2, 2018. Grasses of Australia. Online Resources. http://ausgrass2.myspecies.info/

Chacón E, Saborío G, 2012. Red Interamericana de Información de Especies Invasoras de Costa Rica. San José, Costa Rica: Asociación para la Conservación y el Estudio de la Biodiversidad. http://invasoras.acebio.org

Clayton WD, Govaerts R, Harman KT, Williamson H, Vorontsova M, 2018. World Checklist of Poaceae. Richmond, UK: Royal Botanic Gardens, Kew. http://apps.kew.org/wcsp/

Flora of China Editorial Committee, 2018. Flora of China. St. Louis, Missouri and Cambridge, Massachusetts, USA: Missouri Botanical Garden and Harvard University Herbaria. http://flora.huh.harvard.edu/china/

Flora of Pakistan, 2018. Flora of Pakistan/Pakistan Plant Database (PPD). Tropicos website. St. Louis, Missouri and Cambridge, Massachusetts, USA: Missouri Botanical Garden and Harvard University Herbaria. http://www.tropicos.org/Project/Pakistan

Florence J, Chevillotte H, Ollier C, Meyer JY, 2013. Botanical database of the Nadeaud Herbarium of French Polynesia. (Base de données botaniques Nadeaud de l'Herbier de la Polynésie Française). http://www.herbier-tahiti.pf

GRIIS, 2018. Global Register of Introduced and Invasive Species. Global Invasive Alien Species Information Partnership and the IUCN SSC Invasive Species Specialist Group. http://www.griis.org/

Gupta AK, 2013. Brachiaria reptans. In: The IUCN Red List of Threatened Species 2013, http://dx.doi.org/10.2305/IUCN.UK.2013-1.RLTS.T169043A1267310.en

Hammel, B. E., Grayum, M. H., Herrera, C., Zamora, N. , 2003. Manual de Plantas de Costa Rica, Volumen III: Monocotiledóneas (Orchidaceae-Zingiberaceae), [ed. by Hammel, B. E., Grayum, M. H., Herrera, C., Zamora, N. ]. St. Louis, USA: Missouri Botanical Garden Press.xvi + 884 pp.

Ibrahim KM, Hosni HA, Peterson PM, 2016. Grasses of Egypt, Washington DC, USA: Smithsonian Institution Scholarly Press.

India Biodiversity Portal, 2018. Online Portal of India Biodiversity. https://indiabiodiversity.org/

Mahmood, I., 1988. Two possible new hosts of Meloidogyne incognita. International Nematology Network Newsletter, 5(1), 20.

Más EG, García-Molinari O, 2006. [English title not available]. (Guía ilustrada de yerbas comunes en Puerto Rico). Puerto Rico, USA: University of Puerto Rico and USDA-NRCS.

PIER, 2018. Pacific Islands Ecosystems at Risk. Honolulu, Hawaii, USA: HEAR, University of Hawaii. http://www.hear.org/pier/index.html

Rojas-Sandoval, J., Acevedo-Rodríguez, P., 2015. Naturalization and invasion of alien plants in Puerto Rico and the Virgin Islands. Biological Invasions, 17(1), 149-163. http://rd.springer.com/article/10.1007/s10530-014-0712-3/fulltext.html doi: 10.1007/s10530-014-0712-3

Salariato, D. L., Giussani, L. M., Morrone, O., Zuloaga, F. O., 2009. Rupichloa, a new genus segregated from Urochloa (Poaceae) based on morphological and molecular data. Taxon, 58(2), 381-391. http://www.taxon-manuscripts.org

Salariato, D. L., Zuloaga, F. O., Giussani, L. M., Morrone, O., 2010. Molecular phylogeny of the subtribe Melinidinae (Poaceae: Panicoideae: Paniceae) and evolutionary trends in the homogenization of inflorescences. Molecular Phylogenetics and Evolution, 56(1), 355-369. doi: 10.1016/j.ympev.2010.02.009

Sánchez-Ken, J. G., 2011. Two new species of Urochloa (Paniceae; Panicoideae; Poaceae) from western Mexico and the updated checklist with a key to species of the genus in Mexico. Systematic Botany, 36(3), 621-630. http://www.bioone.org/doi/abs/10.1600/036364411X583619 doi: 10.1600/036364411X583619

Shirasuna RT, 2015. Urochloa. 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/FB105508

Simon, B. K., Jacobs, S. W. L., 2003. Megathyrsus, a new generic name for Panicum subgenus Megathyrsus. Austrobaileya, 6(3), 571-574.

Stevens PF, 2017. Angiosperm Phylogeny Website. St. Louis, Missouri, USA: Missouri Botanical Garden. http://www.mobot.org/MOBOT/research/APweb/

Tiwari, J. P., Kurchania, S. P., 1990. Survey and management of weeds in soybean (Glycine max) ecosystem in Madhya Pradesh. Indian Journal of Agricultural Sciences, 60(10), 672-676.

Torres González, A. M., Morton, C. M., 2005. Molecular and morphological phylogenetic analysis of Brachiaria and Urochloa (Poaceae). Molecular Phylogenetics and Evolution, 37(1), 36-44. http://www.sciencedirect.com/science/journal/10557903 doi: 10.1016/j.ympev.2005.06.003

USDA-ARS, 2018. Germplasm Resources Information Network (GRIN). Online Database. Beltsville, USA: National Germplasm Resources Laboratory. http://www.ars-grin.gov/cgi-bin/npgs/html/tax_search.pl

USDA-NRCS, 2018. The PLANTS Database. Baton Rouge, USA: National Plant Data Center. http://plants.usda.gov/

Veldkamp, J. F., 1996. Brachiaria, Urochloa (Gramineae-Paniceae) in Malesia. Blumea, 41(2), 413-437.

Waterhouse DF, 1993. The Major Arthropod Pests and Weeds of Agriculture in Southeast Asia. ACIAR Monograph No. 21. Canberra, Australia: Australian Centre for International Agricultural Research, 141 pp

Watson L, Macfarlane TD, Dallwitz MJ, 1992. Urochloa. In: The grass genera of the world: descriptions, illustrations, identification, and information retrieval, including synonyms, morphology, anatomy, physiology, phytochemistry, cytology, classification, pathogens, world and local distribution, and references. Version: 20th August 2018, http://www.delta-intkey.com/grass/www/urochloa.htm

Contributors

12/08/18 Original text by:

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

Distribution Maps