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]

Chinese: shi zi cao

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)
State of Hawaii Hawaiian Islands	O‘ahu Island	introduced invasive	Snow, Neil/Davidse, Gerrit (2011) (p. 20) Voucher cited: SESP s.n. (BISH 667204)

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. (2011)
Japan Japan	Japan (country)	introduced	Mito, Toshikazu/Uesugi, Tetsuro (2004) (p. 192)
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).

References:

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

Mito, Toshikazu/Uesugi, Tetsuro. 2004. Invasive alien species in Japan: the status quo and the new regulation for prevention of their adverse effects. Global Environmental Research 8(2)/2004: 171-191.

Snow, Neil/Davidse, Gerrit. 2011. Notes on grasses (Poaceae) in Hawai‘i:3. In: Evenhuis, Neal L. and Eldredge, Lucius G., eds. Records of the Hawaii Biological Survey for 2009-2010. Part II: Plants. Bishop Museum Occasional Papers. 110:11-22.

U.S. Dept. Agr., Agr. Res. Serv. 2011. 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).

Zhengyi, Wu/Raven, Peter H./Deyuan, Hong. 2011. Flora of China (online resource).