Invasive Species Compendium

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Datasheet

Themeda arguens
(Christmas grass)

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Datasheet

Themeda arguens (Christmas grass)

Summary

  • Last modified
  • 16 November 2018
  • Datasheet Type(s)
  • Invasive Species
  • Preferred Scientific Name
  • Themeda arguens
  • Preferred Common Name
  • Christmas grass
  • Taxonomic Tree
  • Domain: Eukaryota
  •   Kingdom: Plantae
  •     Phylum: Spermatophyta
  •       Subphylum: Angiospermae
  •         Class: Monocotyledonae
  • Summary of Invasiveness
  • T. arguens is a fast growing and very aggressive grass. At present, this species has been listed as invasive in Jamaica and Fiji, and it is spreading across these islands displacing and outcompeting native gras...

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    OX10 8DE
    UK
    compend@cabi.org
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Identity

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Preferred Scientific Name

  • Themeda arguens (L.) Hack.

Preferred Common Name

  • Christmas grass

Other Scientific Names

  • Anthistiria arguens (L.) Willd
  • Anthistiria ciliata var. junghuhniana Buse
  • Anthistiria ciliata var. major Thwaites
  • Anthistiria frondosa R.Br.
  • Anthistiria pilifera Steud.
  • Aristaria barbata Jungh.
  • Stipa arguens L.
  • Themeda arguens var. balinensis Jansen
  • Themeda arguens var. cochinchinensis A.Camus
  • Themeda frondosa (R.Br.) Merr.

International Common Names

  • English: grader grass; lesser tassel grass; piano grass

Local Common Names

  • Indonesia: rumput merak

Summary of Invasiveness

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T. arguens is a fast growing and very aggressive grass. At present, this species has been listed as invasive in Jamaica and Fiji, and it is spreading across these islands displacing and outcompeting native grasses and herbs (IABIN, 2014; PIER, 2014). In areas invaded by this grass, livestock tend to avoid it for more palatable species resulting in the dominance of T. arguens over other low growing species (Motta, 1953). In addition, T. arguens seeds heavily and seeds can be easily dispersed by wind, vehicles, animals, and attached to clothes and mud. The practice of using dry grass stems as packing for provisions being carried to market is another common cause for the introduction and spread of this species (Motta, 1953; PIER, 2014). 

Taxonomic Tree

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

Notes on Taxonomy and Nomenclature

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Themeda is a genus of about 18 to 27 species, all of which are native to tropical and subtropical regions of the Old World, primarily Southeast Asia (Barkworth, 2003; Flora of China Editorial Committee, 2014). Member of this genus are annual or perennial species, usually cespitose, rarely stoloniferous. The name Themeda comes from the Arabic thaemed, the term for a depression where water collects after rain and later evaporates, referring to the habitat of some species of this genus (Barkworth, 2003). One of the common names for this species, piano grass, comes from the theory that it was introduced to Jamaica as a contaminant in packing material with an imported piano.

Description

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T. arguens is an annual, caespitose grass. Culms erect; 20–120 cm long. Leaves mostly basal. Ligule an eciliate membrane; 1 mm long. Leaf-blade base broadly rounded. Leaf-blades flat, or conduplicate; 5–30 cm long; 4–7 mm wide. Leaf-blade apex acuminate. Inflorescence composed of racemes; terminal and axillary; subtended by a spatheole. Spatheole lanceolate; 2.5–3.5 cm long; scarious; without tubercles; glabrous. Racemes 1; single; cuneate; bearing few fertile spikelets; bearing 1 fertile spikelets on each. Rhachis fragile at the nodes. Spikelets in threes (basal paired). Fertile spikelets sessile; 1 in the cluster. Companion sterile spikelets pedicelled; 2 in the cluster. Pedicels oblong; 1 mm long; tip oblique. Basal sterile spikelets represented by a single scale; 4 in number; forming an involucre about the fertile; with both pairs arising at about the same level; subsessile; 6–10 mm long; equaling fertile. Basal sterile spikelet glumes smooth; glabrous; lower glume muticous. Companion sterile spikelets well-developed; comprising 2 subequal glumes without lemmas; lanceolate; 6 mm long; shorter than fertile; separately deciduous. Companion sterile spikelet callus linear; 2–3 mm long; truncate. Companion sterile spikelet glumes herbaceous; glabrous; acuminate. Spikelets comprising 1 basal sterile florets; 1 fertile florets; without rhachilla extension. Spikelets elliptic; subterete; 8–10 mm long; falling entire; deciduous with accessory branch structures. Spikelet callus linear; 3 mm long; bearded; base pungent; attached obliquely. Spikelet callus hairs red. Glumes dissimilar; exceeding apex of florets; firmer than fertile lemma. Lower glume oblong; 1 length of spikelet; coriaceous; dark brown; without keels; 7 -veined. Lower glume surface pilose; hairy above. Lower glume hairs dark brown. Lower glume apex truncate. Upper glume oblong; coriaceous; with membranous margins; 3 -veined. Upper glume surface pilose; hairy above. Upper glume margins ciliate. Upper glume hairs dark brown. Upper glume apex truncate. Basal sterile florets barren; without significant palea. Lemma of lower sterile floret oblong; 2.8 mm long; hyaline; ciliate on margins. Fertile lemma oblong; 3 mm long; hyaline; without keel; 1 -veined. Lemma apex entire; awned; 1 -awned. Principal lemma awn apical; geniculate; 50–70 mm long overall; with twisted column. Column of lemma awn hispidulous. Palea absent or minute. Anthers 1.4 mm long (Clayton et al., 2014). 

Plant Type

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Grass / sedge
Seed propagated

Distribution

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T. arguens is native to temperate Asia, from Sri Lanka to Australia and New Guinea. It has been introduced in the West Indies, the USA (i.e., Maryland and Virginia) and Fiji (see distribution table for details, Clayton et al., 2014; PIER, 2014; USDA-ARS, 2014).

Distribution Table

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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.

Continent/Country/RegionDistributionLast ReportedOriginFirst ReportedInvasiveReferenceNotes

Asia

IndiaPresentPresent based on regional distribution.
-Andaman and Nicobar IslandsPresentNativeClayton et al., 2014
IndonesiaPresentPresent based on regional distribution.
-JavaPresentNativeClayton et al., 2014
-MoluccasPresentNativeClayton et al., 2014
-Nusa TenggaraPresentNativeClayton et al., 2014
-SulawesiPresentNativeClayton et al., 2014
-SumatraPresentNativeClayton et al., 2014
LaosPresentNativeClayton et al., 2014
MalaysiaPresentPresent based on regional distribution.
-Peninsular MalaysiaPresentNativeClayton et al., 2014
MyanmarPresentNativeClayton et al., 2014
PhilippinesPresentPIER, 2014
SingaporePresent Invasive Chong et al., 2009
Sri LankaPresentNativeClayton et al., 2014
ThailandPresentNativeClayton et al., 2014
VietnamPresentNativeClayton et al., 2014

North America

USAPresentPresent based on regional distribution.
-MarylandPresentIntroducedUSDA-NRCS, 2014
-VirginiaPresentIntroducedUSDA-NRCS, 2014

Central America and Caribbean

BarbadosPresentIntroducedAcevedo-Rodriguez and Strong, 2012
CubaPresentIntroducedMissouri Botanical Garden, 2014
GuadeloupePresentIntroducedLiogier and Martorell, 2000
JamaicaPresentIntroduced Invasive IABIN, 2014
Puerto RicoPresentIntroducedLiogier and Martorell, 2000

Oceania

AustraliaPresentPresent based on regional distribution.
-Australian Northern TerritoryPresentNativeClayton et al., 2014
-QueenslandPresentNativeClayton et al., 2014
-Western AustraliaPresentUSDA-ARS, 2014
FijiPresentIntroduced Invasive PIER, 2014
New CaledoniaPresentToutain and Veillon, 1990
Papua New GuineaPresentNativeClayton et al., 2014

History of Introduction and Spread

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In Jamaica, T. arguens was first collected in the wild in 1912 (US National Herbarium), but it was apparently introduced earlier as a contaminant in packing material with an imported piano (Motta, 1953). In Barbados, it was first reported in 1927 (Hitchcock, 1936). By 1964, this species was reported occurring in the USA (Maryland and Virginia). In 1981, it was reported as a naturalized grass occurring along roadsides in Puerto Rico (Liogier, 1981). 

Risk of Introduction

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The risk of introduction of T. arguens is moderate. Because this grass is palatable and eaten by livestock only when plants are young, it is rarely planted and grown in pastures. However, once established it produces large amounts of seeds which can easily be transported by animals and vehicles, in clothing and mud, and as a contaminant of agricultural produce. The seeds are also commonly dispersed during soil moving activities (Motta, 1953; PIER, 2014; USDA-ARS, 2014).

Habitat

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T. arguens grows as a weed in disturbed sites, waste areas, open woodlands, grasslands, pastures, and along roadsides in tropical and sub-tropical regions (Liogier and Martorell, 2000; Clayton et al., 2014; PIER, 2014; USDA-ARS, 2014). 

Habitat List

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CategorySub-CategoryHabitatPresenceStatus
Terrestrial
Terrestrial – ManagedCultivated / agricultural land Present, no further details Harmful (pest or invasive)
Cultivated / agricultural land Present, no further details Natural
Cultivated / agricultural land Present, no further details Productive/non-natural
Managed forests, plantations and orchards Present, no further details Harmful (pest or invasive)
Managed forests, plantations and orchards Present, no further details Natural
Managed forests, plantations and orchards Present, no further details Productive/non-natural
Managed grasslands (grazing systems) Present, no further details Harmful (pest or invasive)
Managed grasslands (grazing systems) Present, no further details Natural
Managed grasslands (grazing systems) Present, no further details Productive/non-natural
Disturbed areas Present, no further details Harmful (pest or invasive)
Disturbed areas Present, no further details Natural
Rail / roadsides Present, no further details Harmful (pest or invasive)
Rail / roadsides Present, no further details Natural
Terrestrial ‑ Natural / Semi-naturalNatural grasslands Present, no further details Harmful (pest or invasive)
Natural grasslands Present, no further details Natural

Biology and Ecology

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Genetics

The chromosome number reported for T. arguens is 2n = 20 (Barkworth, 2003).

Phenology

In Fiji, T. arguens flowers between May and August (Smith, 1979).

Longevity

T. arguens is a short-lived (annual) grass (Barkworth, 2003).

Climate

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ClimateStatusDescriptionRemark
Af - Tropical rainforest climate Preferred > 60mm precipitation per month
Am - Tropical monsoon climate Preferred Tropical monsoon climate ( < 60mm precipitation driest month but > (100 - [total annual precipitation(mm}/25]))
As - Tropical savanna climate with dry summer Preferred < 60mm precipitation driest month (in summer) and < (100 - [total annual precipitation{mm}/25])
Aw - Tropical wet and dry savanna climate Preferred < 60mm precipitation driest month (in winter) and < (100 - [total annual precipitation{mm}/25])
Cs - Warm temperate climate with dry summer Tolerated Warm average temp. > 10°C, Cold average temp. > 0°C, dry summers
Cw - Warm temperate climate with dry winter Tolerated Warm temperate climate with dry winter (Warm average temp. > 10°C, Cold average temp. > 0°C, dry winters)

Soil Tolerances

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Soil texture

  • light
  • medium

Means of Movement and Dispersal

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T. arguens spread by seeds. Seeds can be easily transported by wind, animals and vehicles, in clothing and mud, and as a contaminant of agricultural produce and packing material (Motta, 1953; PIER, 2014; USDA-ARS, 2014).

Pathway Causes

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CauseNotesLong DistanceLocalReferences
ForageYoung plants used as forage Yes Yes Smith, 1979

Pathway Vectors

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VectorNotesLong DistanceLocalReferences
Containers and packaging - woodIntroduced in contaminated straw packing Yes Yes Motta, 1953
Land vehiclesSeeds Yes Yes Motta, 1953

Impact Summary

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CategoryImpact
Economic/livelihood Positive and negative
Environment (generally) Positive and negative

Economic Impact

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Younger plants of T. arguens are eaten by livestock, however flowering plants are unpalatable and rarely grazed. Motta (1953) reports that the floral awns cause severe damage to the mouths of grazing cattle. Because of its short period of usefulness and propensity to outcompete more useful grasses, it can seriously reduce the productivity of pastures (Smith, 1979).

Environmental Impact

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T. arguens is an environmental weed. It has been listed as invasive in Jamaica and Fiji (IABIN, 2014; PIER, 2014). This species is a very aggressive grass with the potential to reduce the biodiversity of native forests and grasslands. Once established, it grows forming dense thickets that can smother native vegetation (Motta, 1953; PIER, 2014; USDA-ARS, 2014). 

Risk and Impact Factors

Top of page Invasiveness
  • Proved invasive outside its native range
  • Has a broad 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
  • Gregarious
Impact outcomes
  • Ecosystem change/ habitat alteration
  • Modification of successional patterns
  • Monoculture formation
  • Reduced native biodiversity
  • Threat to/ loss of native species
Impact mechanisms
  • Competition - monopolizing resources
  • Competition - smothering
  • Rapid growth
Likelihood of entry/control
  • Highly likely to be transported internationally accidentally
  • Difficult to identify/detect as a commodity contaminant
  • Difficult to identify/detect in the field

Uses

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T. arguens is used as forage for livestock when young (Smith, 1979; Motta, 1953) and its stems (straw) are used as packing material (Motta, 1953). 

Uses List

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Animal feed, fodder, forage

  • Forage

Similarities to Other Species/Conditions

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T. arguens is very similar to Themeda quadrivalvis, which is also an invasive species in many regions of the world (Queensland Department of Primary Industries and Fisheries, 2011; PIER, 2014). These species can be distinguished by the following differences:

  • T. arguens is a large short-lived (i.e. annual) grass growing up to 3 m tall. Its individual flower spikelets are moderately-sized (6-11 mm long), softly hairy (i.e. pubescent), and topped with a large and robust awn (50-90 mm long).
  • Themeda quadrivalvis is a moderately-sized to relatively large short-lived (i.e. annual) grass growing up to 1.8 m tall. Its individual flower spikelets are relatively small (4-7 mm long), stiffly hairy (i.e. setose) in the upper half, and its seeds are topped with a relatively fine awn (10-45 mm long).

Prevention and Control

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Most information found on control of this species as a weed comes from extension literature in Jamaica from the 1950s and 1960s. Motta (1955) reported that pangola grass (Digitaria eriantha) is capable of smothering T. arguens when properly managed. Larter (1947) also said that competitive grasses could suppress T. arguens. Motta (1953) suggested that areas with large infestations should be ploughed and cultivated and replanted with sugar cane or a smothering grass. Where only a few roots are present, these may be dug up and burned and the area treated with oil. Jamaican literature also reports effective control with the herbicide dalapon.

References

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Acevedo-Rodríguez P; Strong MT, 2012. Catalogue of the Seed Plants of the West Indies. Smithsonian Contributions to Botany, 98:1192 pp. Washington DC, USA: Smithsonian Institution. http://botany.si.edu/Antilles/WestIndies/catalog.htm

Barkworth ME, 2003. Themeda. Flora of North America vol. 25 [ed. by Barkworth, M. E. \Capels, K. M. \Long, S. \Piep, M. B. \(.]. http://herbarium.usu.edu/

Chong KY; Tan HTW; Corlett RT, 2009. A checklist of the total vascular plant flora of Singapore: native, naturalised and cultivated species. Singapore: Raffles Museum of Biodiversity Research, National University of Singapore, 273 pp. http://lkcnhm.nus.edu.sg/nus/pdf/PUBLICATION/LKCNH%20Museum%20Books/LKCNHM%20Books/flora_of_singapore_tc.pdf

Clayton WD; Govaerts R; Harman KT; Williamson H; Vorontsova M, 2014. GrassBase - The Online World Grass Flora. http://www.kew.org/data/grasses-db.html

Flora of China Editorial Committee, 2014. Flora of China. St. Louis, Missouri and Cambridge, Massachusetts, USA: Missouri Botanical Garden and Harvard University Herbaria. http://www.efloras.org/flora_page.aspx?flora_id=2

Hitchcock AS, 1936. Manual of the grasses of the West Indies. Washington, DC, USA: United States Department of Agriculture. [USDA Miscellaneous Publication no. 243.]

IABIN, 2014. List of Alien Invasive Species occurring in Jamaica. The United States Node of the Inter-American Biodiversity Information Net (IABIN). http://www.iabin-us.org/projects/i3n/i3n_documents/catalogs/catalog_jamaica.html

Larter LNH, 1947. Control of piano grass. Tropical Agriculture, Trinidad and Tobago, 24:57-60.

Liogier AH, 1981. Novitates Antillanae. IX. Phytologia, 50(3):161-170.

Liogier HA; Martorell LF, 2000. Flora of Puerto Rico and adjacent islands: a systematic synopsis, 2nd edition revised. San Juan, Puerto Rico: La Editorial, University of Puerto Rico, 382 pp.

Missouri Botanical Garden, 2014. Tropicos database. St. Louis, Missouri, USA: Missouri Botanical Garden. http://www.tropicos.org/

Motta MS, 1953. Piano grass. Extension Circular 51., Jamaica: Department of Agriculture. http://krishikosh.egranth.ac.in/bitstream/1/2031071/1/43310.pdf

Motta MS, 1955. Control of weeds in pastures. Bull. Dep. Agric. Jamaica, 54:102.

PIER, 2014. Pacific Islands Ecosystems at Risk. Honolulu, USA: HEAR, University of Hawaii. http://www.hear.org/pier/index.html

Queensland Department of Primary Industries and Fisheries, 2011. Special edition of Environmental Weeds of Australia for Biosecurity Queensland., Australia: The University of Queensland and Department of Primary Industries and Fisheries. http://keyserver.lucidcentral.org/weeds/data/03030800-0b07-490a-8d04-0605030c0f01/media/Html/Index.htm

Smith AC, 1979. Flora Vitiensis nova: A new flora of Fiji. Volume I. Lawai, Kauai, Hawaii, USA: National Tropical Botanical Garden, 494 pp.

Toutain B; Veillon JM, 1990. Observations on grasses of the genus Themeda in New Caledonia. (Observations à propos de graminées de genre Themeda en Nouvell-Calédonie.) Revue d'Élevage et de Médecine Vétérinaire de Nouvelle Calédonie, No. 13:15-18.

USDA-ARS, 2014. Germplasm Resources Information Network (GRIN). Online Database. Beltsville, Maryland, USA: National Germplasm Resources Laboratory. https://npgsweb.ars-grin.gov/gringlobal/taxon/taxonomysearch.aspx

USDA-NRCS, 2014. The PLANTS Database. Baton Rouge, USA: National Plant Data Center. http://plants.usda.gov/

Links to Websites

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WebsiteURLComment
GISD/IASPMR: Invasive Alien Species Pathway Management Resource and DAISIE European Invasive Alien Species Gatewayhttps://doi.org/10.5061/dryad.m93f6Data source for updated system data added to species habitat list.
GrassBase - The Online World Grass Florahttp://www.kew.org/data/grasses-db/www/imp10752.htm
Grasses in North Americahttp://herbarium.usu.edu/webmanual/
Kew World Checklist of Selected Plant Familieshttp://apps.kew.org/wcsp/

Contributors

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10/01/15 Original text by:

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

Pedro Acevedo-Rodríguez, Department of Botany-Smithsonian NMNH, Washington DC, USA

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