Tripsacum dactyloides
(eastern gamagrass)

Pictures

Picture	Title	Caption	Copyright
Title Habit Caption Tripsacum dactyloides (eastern gamagrass); habit. Common along road sides and similar moderately disturbed settings. Plains, Georgia, USA. August 2003. Copyright ©Prof Matt Lavin-2003/Bozeman, Montana, USA/via flickr - CC BY-SA 2.0	Habit	Tripsacum dactyloides (eastern gamagrass); habit. Common along road sides and similar moderately disturbed settings. Plains, Georgia, USA. August 2003.	©Prof Matt Lavin-2003/Bozeman, Montana, USA/via flickr - CC BY-SA 2.0
Title Habit Caption Tripsacum dactyloides (eastern gamagrass); habit. Common along road sides and similar moderately disturbed settings. Plains, Georgia, USA. August 2003. Copyright ©Prof Matt Lavin-2003/Bozeman, Montana, USA/via flickr - CC BY-SA 2.0	Habit	Tripsacum dactyloides (eastern gamagrass); habit. Common along road sides and similar moderately disturbed settings. Plains, Georgia, USA. August 2003.	©Prof Matt Lavin-2003/Bozeman, Montana, USA/via flickr - CC BY-SA 2.0
Title Habit Caption Tripsacum dactyloides (eastern gamagrass); habit and seedhead. Mealani Agricultural Station, Waimea, Hawaii. USA July 2012. Copyright ©Forest & Kim Starr - CC BY 4.0	Habit	Tripsacum dactyloides (eastern gamagrass); habit and seedhead. Mealani Agricultural Station, Waimea, Hawaii. USA July 2012.	©Forest & Kim Starr - CC BY 4.0
Title Spikelts Caption Tripsacum dactyloides (eastern gamagrass); spiklets. The pistillate spikelets are embedded in the main rachis, and one spikelet and an adjacent internode rachis harden and disarticulate as a dispersal unit (similar to Aegilops). Common along roadsides and similar moderately disturbed settings. Plains, Georgia, USA. August 2003. Copyright ©Prof Matt Lavin-2003/Bozeman, Montana, USA/via flickr - CC BY-SA 2.0	Spikelts	Tripsacum dactyloides (eastern gamagrass); spiklets. The pistillate spikelets are embedded in the main rachis, and one spikelet and an adjacent internode rachis harden and disarticulate as a dispersal unit (similar to Aegilops). Common along roadsides and similar moderately disturbed settings. Plains, Georgia, USA. August 2003.	©Prof Matt Lavin-2003/Bozeman, Montana, USA/via flickr - CC BY-SA 2.0
Title Spikelets Caption Tripsacum dactyloides (eastern gamagrass); spiklets. The pistillate spikelets are embedded in the main rachis, and one spikelet and an adjacent internode rachis harden and disarticulate as a dispersal unit (similar to Aegilops). Common along roadsides and similar moderately disturbed settings. Plains, Georgia, USA. August 2003. Copyright ©Prof Matt Lavin-2003/Bozeman, Montana, USA/via flickr - CC BY-SA 2.0	Spikelets	Tripsacum dactyloides (eastern gamagrass); spiklets. The pistillate spikelets are embedded in the main rachis, and one spikelet and an adjacent internode rachis harden and disarticulate as a dispersal unit (similar to Aegilops). Common along roadsides and similar moderately disturbed settings. Plains, Georgia, USA. August 2003.	©Prof Matt Lavin-2003/Bozeman, Montana, USA/via flickr - CC BY-SA 2.0
Title Spikelets Caption Tripsacum dactyloides (eastern gamagrass); spiklets. The staminate spikelets are paired in the fashion of other general of Andropogoneae. Common along roadsides and similar moderately disturbed settings. Plains, Georgia, USA. August 2003. Copyright ©Prof Matt Lavin-2003/Bozeman, Montana, USA/via flickr - CC BY-SA 2.0	Spikelets	Tripsacum dactyloides (eastern gamagrass); spiklets. The staminate spikelets are paired in the fashion of other general of Andropogoneae. Common along roadsides and similar moderately disturbed settings. Plains, Georgia, USA. August 2003.	©Prof Matt Lavin-2003/Bozeman, Montana, USA/via flickr - CC BY-SA 2.0
Title Seedhead Caption Tripsacum dactyloides (eastern gamagrass); seedhead. Mealani Agricultural Station, Waimea, Hawaii, USA. July 2012. Copyright ©Forest & Kim Starr - CC BY 4.0	Seedhead	Tripsacum dactyloides (eastern gamagrass); seedhead. Mealani Agricultural Station, Waimea, Hawaii, USA. July 2012.	©Forest & Kim Starr - CC BY 4.0
Title Seeds Caption Tripsacum dactyloides (eastern gamagrass); seeds. Mealani Agricultural Station Waimea, Hawaii, USA. July 2012. Copyright ©Forest & Kim Starr - CC BY 4.0	Seeds	Tripsacum dactyloides (eastern gamagrass); seeds. Mealani Agricultural Station Waimea, Hawaii, USA. July 2012.	©Forest & Kim Starr - CC BY 4.0

Identity

Preferred Scientific Name

• Tripsacum dactyloides (L.) L.

Preferred Common Name

• eastern gamagrass

Other Scientific Names

• Coix angulata Mill.
• Coix dactyloides L.
• Dactylodes angulatum Kuntze
• Dactylodes dactyloides (L.) Kuntze
• Ischaemum glabrum Walter
• Tripsacum bravum J.R.Gray
• Tripsacum floridanum Porter ex Vasey
• Tripsacum monostachyon Willd.

International Common Names

• English: bullgrass; eastern mock grama; fakahatchee grass; gamagrass; northern gamagrass; sesame grass; wild corn
• Spanish: maicillo oriental; pasto Guatemala; zacate maicero
• French: herbe de gama; herbe grama; maicillo oriental

Local Common Names

• Brazil: capim gigante
• Cuba: zacate
• Dominican Republic: lagon
• Germany: Gamagras; Gama-Gras
• Haiti: herbe rasoir
• Mexico: zacate maicero

EPPO code

• TRWDA (Tripsacum dactyloides)

Summary of Invasiveness

Tripsacum dactyloides is cultivated as a forage crop in areas within and outside its native distribution range. The species establishes slowly and competes poorly with annual grasses and weeds during its first year of establishment, but after that, it competes effectively with most perennial and broadleaf plants. Currently, T. dactyloides is listed as invasive only in Cuba. However, this species is often reported to be growing as a 'weed' in ruderal areas, forest edges, and disturbed and open forests in areas within and outside its native distribution range.

Taxonomic Tree

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

Notes on Taxonomy and Nomenclature

Poaceae is one of the largest families of flowering plants comprising 707 genera and more than 11,300 species distributed worldwide (Stevens, 2012). The genus Tripsacum contains 14 species, which occur from temperate North America to Paraguay in South America (Zuloaga et al., 2003; Clayton et al., 2017; Missouri Botanical Garden, 2017). Tripsacum is closely related to Zea, the genus containing the cultigen maize and its wild relatives known as 'teosintes'. These two genera share a number of morphological features, including the highly specialized cupulate fruitcase and the spikelet arrangement. They also have the potential to cross and produce viable but typically infertile hybrids.  Because of their affinity to maize, Tripsacum species have been the subjects of numerous evolutionary, taxonomic and biosystematics studies and many cultivars have been developed (Doebley, 1983; Cook et al., 2005, USDA-NRCS, 2017).

Description

The following description is from Cook et al. (2005): An extremely variable perennial clump grass, with short, fibrous, knotty rhizomes and deep, hollow roots. Culms 2-3 (-4 m) tall, and 3-5 cm thick at base, branching, prop-rooting from lower nodes; stems purplish, glabrous. Leaf sheath glabrous, often purplish; leaf-blade lanceolate-acuminate, up to 1.5 m long and 9-35 mm wide, mostly glabrous, sometimes hairy at the base of the upper blade surface; margin scabrous; ligule a fringe of hairs, 1-1.5 mm long, prominent midrib. Inflorescence 10-20 (-30) cm long, terminal and axillary, commonly a single raceme, or subdigitate panicle comprising 2-3 (-6) racemes of usually unisexual awnless spikelets (gynomonoecious types have been found); the female (pistillate) spikelets (green when immature), occupying the basal one-eighth to one-third of the raceme, inserted singly and alternately on opposite sides of the thick, hard articulate lower part of the rachis, sunken in hollows in the joints; oval in section, hard, separating into bead-like segments 7-10 mm long at maturity: the male (staminate) spikelets 7-11 mm long (purplish when immature) inserted in pairs at either side of oblique nodes, and on one side of the flattened rachis at the terminal end of the raceme; anthers cream to orange, stigmas white to purple, up to 2.5 cm long.

Plant Type

Distribution

Tripsacum dactyloides is native to the United States, Mexico, Central and South America and the Caribbean region (Zuloaga et al., 2003; Clayton et al., 2017; USDA-ARS, 2017). It was introduced through cultivation as a forage crop and is now naturalized in tropical Asia, India, Malaysia, Philippines and Australia (Clayton et al., 2017; FAO, 2017; Randall, 2017).

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

Tripsacum dactyloides has been introduced as a forage crop. It is also cultivated as a hay and silage crop, for soil conservation, and for erosion control. Across the United States, interest in T. dactyloides increased significantly during the late 1980s and early 1990s, mainly due to its ability to produce large quantities of high quality forage during the summer months (USDA-NRCS, 2017). In Malaysia, this species has been extensively planted on rubber estates as a soil conditioner in drained swamps, and for mulching (Gilliland, 1971; FAO, 2017).

Habitat

Tripsacum dactyloides can be found growing in prairies, coastal plains, semi-arid regions, deep sandy soils, rocky outcrops, river and stream banks, clearings in forested areas, wet grasslands, and around the edges of marshes (Cook et al., 2005; Vibrans, 2011; FAO, 2017).

Habitat List

Biology and Ecology

Genetics

Tripsacum dactyloides is a wild genetic relative of cultivated maize Zea mays, and it has been suggested that Zea mays may be the result of a cross between T. dactyloides and Zea diploperennis, a perennial variety of teosinte. Like other Tripsacum species, T. dactyloides can hybridize with domesticated maize and teosinte species, although offspring of direct crosses are typically sterile (Vibrans, 2011; Shavrukov and Sokolov, 2015; USDA-NRCS, 2017).

For T. dactyloides, the chromosome number reported varies greatly from diploid (2n = 2x = 36), to triploid (2n = 3x = 54), tetraploid (2n = 4x = 72), pentaploid (2n = 5x = 90), and hexaploid (2n = 6x = 108). Diploid plants reproduce sexually, whereas the polyploids are facultative apomicts. Crossing between the sexual diploids and the polyploids can occur (Vibrans, 2011; USDA-NRCS, 2017).

Reproductive Biology

Tripsacum dactyloides has separate male and female flowers (monoecious), but each spike contains both male and female flowers. Male flowers occupy the top portion of the spike and female flowers the bottom portion. Only the diploid plants are sexual and cross-pollinated. The tetraploids and the rest of the polyploids are apomictic and produce seeds asexually (Shavrukov and Sokolov, 2015; USDA-NRCS, 2017; USDA-ARS, 2017).

Physiology and Phenology

Tripsacum dactyloides is a C₄ grass (Cook et al., 2005). Flowering and fruiting of T. dactyloides extends from April to November in the northern hemisphere (Vibrans, 2011; FAO, 2017; USDA-NRCS, 2017).

Longevity

Tripsacum dactyloides is a perennial, long-lived species that may live up to 50 years (USDA-NRCS, 2017).

Environmental Requirements

Tripsacum dactyloides grows best in areas with mean annual temperatures from 12°C to about 24°C and mean annual rainfall ranging from 900 to 1500 mm, at elevations from sea level to 2750 m. It can tolerate an annual rainfall of 600 mm (Cook et al., 2005). The species prefers moist, moderately well-drained, fertile soils, with textures ranging from sand to clay and pH from 5.5-7.5. It is also adapted to poorly drained soils, but has low salt tolerance. Stands are reduced but not killed by 3 weeks of flooding. The species has a dense root system extending to 4.5 m depth, facilitating moderate drought tolerance. Plants may survive temperatures as low as -30°C, but require at least 140 frost-free daysper year for long-term persistence (Cook et al., 2005; USDA-ARS, 2017; USDA-NRCS, 2017).

Climate

Latitude/Altitude Ranges

Air Temperature

Rainfall

Rainfall Regime

Soil Tolerances

Soil drainage

• free
• seasonally waterlogged

Soil reaction

• acid
• neutral

Soil texture

• light
• medium

Natural enemies

Notes on Natural Enemies

Seed and forage yield can be reduced by the insects Sphenophorus maidis (maize billbug), Diatraea crambidoides (southern cornstalk borer), and Diatraea grandiosella (southwestern corn borer). Seeds are frequently consumed by birds (Cook et al., 2005; USDA-NRCS, 2017). T. dactyloides is also a host plant for skipper butterflies (Lepidoptera: Hesperiidae) such as the bunchgrass skipper (Problema byssus), clouded skipper (Lerema accius) and three-spotted skipper (Cymaenes tripunctatus) (Cook et al., 2005). Two viruses transmitted by aphids, sugarcane mosaic virus and maize dwarf mosaic virus, can infect T. dactyloides plants (USDA-NRCS, 2017).

Means of Movement and Dispersal

Natural Dispersal

Tripsacum dactyloides spreads by seeds. The species may yield 12,000-15,000 seeds/kg (Cook et al., 2005).

Intentional Introduction

Tripsacum dactyloides has been intentionally introduced as a forage, hay and silage crop. It is cultivated in areas within and outside its native distribution range (USDA-NRCS, 2017).  

Pathway Causes

Pathway Vectors

Impact Summary

Impact

Tripsacum dactyloides forms extensive and persistent stands which have the potential to outcompete and displace native species (USDA-ARS, 2017; USDA-NRCS, 2017). The species is only listed as invasive in Cuba (Oviedo-Prieto and Gonzalez-Oliva, 2015), but there is a lack of information about its competition strategies and the negative impacts associated with the occurrence of this invasive species in Cuba.

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
• Benefits from human association (i.e. it is a human commensal)
• Long lived
• Gregarious
• Reproduces asexually

• Ecosystem change/ habitat alteration
• Monoculture formation

• Competition - monopolizing resources
• Competition - smothering
• Hybridization

• Highly likely to be transported internationally deliberately
• Difficult/costly to control

Uses

Economic Value

Tripsacum dactyloides is cultivated for forage, fodder, hay and silage, for soil conservation, and as an ornamental. The species is often used as a forage crop because its growing season starts earlier than other warm-season grasses and later than cool-season grasses and legumes. It is also palatable and easily digestible by cattle (Cook et al., 2005; USDA-ARS, 2017). 

Environmental Services

Tripsacum dactyloides assists the infiltration of water and improves soil physical and hydraulic properties. Consequently, this species is recommended for filter strips along the edges of agricultural fields, to enhance infiltration and reduce surface runoff. It is also used as a vegetative barrier for soil erosion control and revegetation (Cook et al., 2005; Missouri Botanical Garden, 2017; USDA-NRCS, 2017; USDA-ARS, 2017).

Uses List

Animal feed, fodder, forage

• Fodder/animal feed
• Forage

Environmental

• Erosion control or dune stabilization
• Revegetation
• Soil conservation
• Wildlife habitat

Ornamental

• garden plant
• Propagation material

Prevention and Control

Due to the variable regulations around (de)registration of pesticides, your national list of registered pesticides or relevant authority should be consulted to determine which products are legally allowed for use in your country when considering chemical control. Pesticides should always be used in a lawful manner, consistent with the product's label.

Chemical Control

Tripsacum dactyloides is tolerant of many of the herbicides used to control weeds in maize production such as atrazine, metolachlor, cyanazine, nicosulfuron, rimsulfuron, 2,4-D and dicamba. It is reported to be susceptible to imazapic (Cook et al., 2005).

References

Acevedo-Rodríguez, P., Strong, M. T., 2012. Catalogue of the Seed Plants of the West Indies, Washington, DC, USA: Smithsonian Institution.1192 pp. http://botany.si.edu/Antilles/WestIndies/catalog.htm

AusGrass2, 2015. Grasses of Australia. Online Resources. In: Grasses of Australia. Online Resources . http://ausgrass2.myspecies.info/

Clayton, WD, Govaerts, R, Harman, KT, Williamson, H, Vorontsova, M, 2017. World Checklist of Poaceae. Richmond, UK: Royal Botanic Gardens, Kew.http://apps.kew.org/wcsp/

Cook, B. G., Pengelly, B. C., Brown, S. D., Donnelly, J. L., Eagles, D. A., Franco, M. A., Hanson, J., Mullen, B. F., Partridge, I. J., Peters, M., Schultze-Kraft, R., 2005. Tropical Forages: an interactive selection tool. In: Tropical Forages: an interactive selection tool . Brisbane, Australia: CSIRO, DPI&F, CIAT, ILRI.http://www.tropicalforages.info/

Doebley, J. F., 1983. The taxonomy and evolution of Tripsacum and teosinte, the closest relatives of maize. [International Maize Virus Disease Colloquium and Workshop, Wooster, Ohio (USA), 2-6 Aug 1982], Ohio, USA: Ohio Agricultural Research and Development Center.

FAO, 2017. Grassland Species Profiles. FAO.http://www.fao.org/ag/agp/agpc/doc/gbase/Default.htm

Gilliland, H. B., 1971. A revised flora of Malaya. An illustrated systematic account of the Malayan flora, including commonly cultivated plants. Volume 3. Grasses of Malaya. In: A revised flora of Malaya. An illustrated systematic account of the Malayan flora, including commonly cultivated plants. Volume 3. Grasses of Malaya . Botanic Gardens, Singapore: 319pp.

Missouri Botanical Garden, 2017. Tropicos database. In: Tropicos database St. Louis, Missouri, USA: Missouri Botanical Garden.http://www.tropicos.org/

Oviedo Prieto, R., González-Oliva, L., 2015. National list of invasive and potentially invasive plants in the Republic of Cuba - 2015. (Lista nacional de plantas invasoras y potencialmente invasoras en la República de Cuba - 2015). Bissea: Boletín sobre Conservación de Plantas del Jardín Botánico Nacional de Cuba, 9(Special Issue No. 2), 1-88. http://repositorio.geotech.cu/jspui/bitstream/1234/1476/4/Lista%20nacional%20de%20plantas%20invasoras%20de%20Cuba-2015.pdf

Oviedo Prieto, R., Herrera Oliver, P., Caluff, M. G., et al., 2012. National list of invasive and potentially invasive plants in the Republic of Cuba - 2011. (Lista nacional de especies de plantas invasoras y potencialmente invasoras en la República de Cuba - 2011). Bissea: Boletín sobre Conservación de Plantas del Jardín Botánico Nacional de Cuba, 6(Special Issue No. 1), 22-96.

Randall, R. P., 2017. A global compendium of weeds, (Ed.3) [ed. by Randall, R. P.]. Perth, Australia: R. P. Randall.iii + 3653 pp.

Shavrukov, Y., Sokolov, V., 2015. Maize-gamagrass interspecific hybrid, Zea mays × Tripsacum dactyloides shows better salinity tolerance and higher Na+ exclusion than maize and sorghum. International Journal of Latest Research in Science and Technology, 4, 128-33.

Stevens, P. F., 2012. Angiosperm Phylogeny Website. http://www.mobot.org/MOBOT/research/APweb/

USDA-ARS, 2017. Germplasm Resources Information Network (GRIN). Online Database. In: Germplasm Resources Information Network (GRIN). Online Database Beltsville, Maryland, USA: National Germplasm Resources Laboratory.https://npgsweb.ars-grin.gov/gringlobal/taxon/taxonomysimple.aspx

USDA-NRCS, 2017. The PLANTS Database. In: The PLANTS Database Greensboro, North Carolina, USA: National Plant Data Team.https://plants.sc.egov.usda.gov

Vibrans, H., 2011. Malezas de Mexico. Mexico City, Mexico: CONABIO.http://www.conabio.gob.mx/malezasdemexico/2inicio/home-malezas-mexico.htm

Zuloaga, F. O., Morrone, O., Davidse, G., Filgueiras, T. S., Peterson, P. M., Soreng, R. J., Judziewicz, E. J., 2003. Catalogue of New World Grasses (Poaceae): III. Subfamilies Panicoideae, Aristidoideae, Arundinoideae and Danthonioideae, [ed. by Zuloaga, F. O., Morrone, O., Davidse, G., Filgueiras, T. S., Peterson, P. M., Soreng, R. J., Judziewicz, E.]. Washington, USA: Department of Systematic Biology - Botany, National Museum of Natural History, Smithsonian Institution.662 pp.

Distribution References

Acevedo-Rodríguez P, Strong M T, 2012. Catalogue of the Seed Plants of the West Indies. Washington, DC, USA: Smithsonian Institution. 1192 pp. http://botany.si.edu/Antilles/WestIndies/catalog.htm

AusGrass2, 2015. Grasses of Australia. Online Resources. In: Grasses of Australia. Online Resources. http://ausgrass2.myspecies.info/

Clayton WD, Govaerts R, Harman KT, Williamson H, Vorontsova M, 2017. World Checklist of Poaceae., Richmond, UK: Royal Botanic Gardens, Kew. http://apps.kew.org/wcsp/

Oviedo Prieto R, Herrera Oliver P, Caluff M G, et al, 2012. National list of invasive and potentially invasive plants in the Republic of Cuba - 2011. (Lista nacional de especies de plantas invasoras y potencialmente invasoras en la República de Cuba - 2011). Bissea: Boletín sobre Conservación de Plantas del Jardín Botánico Nacional de Cuba. 6 (Special Issue No. 1), 22-96.

Randall R P, 2017. A global compendium of weeds. [ed. by Randall R P]. Perth, Australia: R. P. Randall. iii + 3653 pp.

USDA-NRCS, 2017. The PLANTS Database. In: The PLANTS Database. Greensboro, North Carolina, USA: National Plant Data Team. https://plants.sc.egov.usda.gov

Zuloaga F O, Morrone O, Davidse G, Filgueiras T S, Peterson P M, Soreng R J, Judziewicz E J, 2003. Catalogue of New World Grasses (Poaceae): III. Subfamilies Panicoideae, Aristidoideae, Arundinoideae and Danthonioideae. [ed. by Zuloaga F O, Morrone O, Davidse G, Filgueiras T S, Peterson P M, Soreng R J, Judziewicz E]. Washington, USA: Department of Systematic Biology - Botany, National Museum of Natural History, Smithsonian Institution. 662 pp.

Links to Websites

Contributors

23/11/17 Original text by:

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

Distribution Maps