Tragus berteronianus Schult., Poaceae

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Present on Pacific Islands?  yes

Primarily a threat at high elevations?  no

Other Latin names:  Nazia aliena (Spreng.) Scribn.

Common name(s): [more details]

English: bertero goatgrass, bur grass, carrotseed grass, small carrot-seed grass, spike bur grass

Habit:  grass

Description:  "Annuals; culms erect or decumbent at base, 1-2.5 dm tall, pubescent below racemes.  Sheaths 1-3 cm long, glabrous, striate, the uppermost often dilated; ligule ciliate, 0.5-0.7 mm long; blades thick, firm, 1.5-2 cm long or the uppermost vestigial, 1-3 mm wide, margins undulate, cartilaginous, pubescent with stiff white hairs.  Racemes 3-7 cm long, 4-5 mm in diameter, often enclosed within the uppermost sheaths, rachis slender, pubescent; burs 2-3 mm long, beaked, pedicels pubescent, up to 0.5 mm long; spikelets 2 per bur; first glume absent, second glumes of the 2 spikelets forming the halves of a bur, convex, 3-nerved, the nerves bearing a row of stout hooked spines on either side; lemma ca. 2 mm long, apex acute, sparsely pubescent; palea 1.5-2 mm long, glabrous, apex acute.  Caryopsis golden brown, 1.2-1.5 mm long"  (Wagner et al., 1999; p. 1601).

Description from GrassBase.

Habitat/ecology:  In Hawai‘i, "naturalized and common along roadsides and in arid, disturbed sites, 25-260 m"  (Wagner et al., 1999; p. 1601).

Propagation:  Seed

Native range:  Native range unknown (Wagner et al., 1999; p. 1601). Africa and Asia, naturalized elsewhere (GRIN).

Presence:

Pacific
Country/Terr./St. & Island group	Location	Cited status & Cited as invasive & Cited as cultivated & Cited as aboriginal introduction?	Reference & Comments
State of Hawaii Hawaiian Islands	Kaho‘olawe Island	introduced invasive	Wagner, Warren L./Herbst, Derral R./Sohmer, S. H. (1999) (p. 1601)
State of Hawaii Hawaiian Islands	Maui Island	introduced invasive	Wagner, Warren L./Herbst, Derral R./Sohmer, S. H. (1999) (p. 1601) Voucher cited: Collector unknown s.n. (BISH)
State of Hawaii Hawaiian Islands	Moloka‘i Island	introduced invasive	Wagner, Warren L./Herbst, Derral R./Sohmer, S. H. (1999) (p. 1601)

Pacific Rim
Country/Terr./St. & Island group	Location	Cited status & Cited as invasive & Cited as cultivated & Cited as aboriginal introduction?	Reference & Comments
China China	China (People's Republic of)	native	U.S. Dept. Agr., Agr. Res. Serv. (2009)
Mexico Mexico	Mexico (United Mexican States)		Hafliger, Ernst/Scholz, Hildemar (1980) (p. 133)

Additional information:
Additional online information about Tragus berteronianus is available from the Hawaiian Ecosystems at Risk project (HEAR).

Information about Tragus berteronianus as a weed (worldwide references) may be available from the Global Compendium of Weeds (GCW).

Taxonomic information about Tragus berteronianus may be available from the Germplasm Resources Information Network (GRIN).

Other Latin names:  Nazia aliena (Spreng.) Scribn.

References:

Hafliger, Ernst/Scholz, Hildemar. 1980. Grass weeds, vol. 2. CIBA-GEIGY Ltd., Basle, Switzerland. 137 pp. + plates.

U.S. Dept. Agr., Agr. Res. Serv. 2009. National Genetic Resources Program. Germplasm Resources Information Network (GRIN). Online searchable database.

Wagner, Warren L./Herbst, Derral R./Sohmer, S. H. 1999. Manual of the flowering plants of Hawaii. Revised edition. Bernice P. Bishop Museum special publication. University of Hawai‘i Press/Bishop Museum Press, Honolulu. 1919 pp. (two volumes).