Cyrtococcum trigonum (Retz.) A. Camus, Poaceae

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Present on Pacific Islands?  yes

Primarily a threat at high elevations?  no

Other Latin names:  Panicum trigonum Retz.

Common name(s): [more details]

English: short-leaf cyrtococcum

Habit:  grass

Description:  "Annual with slender, branching, decumbent or creeping culms, the culms usually widely spreading and often mat-forming, the erect floriferous branches mostly only 10-20 (-30) cm long.  Sheaths ciliate on the margins, often hairy on the sheath node.  Ligule a truncate or rounded membrane 0.3-0.5 mm long.  Blades flat, scabrous, sparsely short-hispid or pilose, mostly 1-3 (-4) cm long and 3-7 mm broad.  Panicles short, few-flowered, contracted or somewhat open, mostly 1.5-6.0 cm long, the spikelets on short, usually appressed pedicels.  First glume 1/2 – 1 1/2 as long as spikelet.  Spikelets laterally flattened.  Second glume and lemma of lower floret appressed-strigose, 3-nerved, the second glume broad and rounded on the back, the lemma longer and narrower.  Lemma and palea of upper floret minutely alveolate, the lemma flattened laterally and "humped up" in the middle"  (Howard, 1979; p. 122).

"Annual, the culms branching, slender, semiprostrate; flowering culms 2.5-30 cm high; panicle few-flowered, open to contracted, 1.2-5 cm long, the ascending side branches 6-12 mm long; spikelets laterally compressed, more or less strongly pilose, 1.5-2 mm long, the upper glume keeled" (Smith, 1979; p. 351).

"Small grass similar to [C. oxyphyllum and C. patens], but with smaller leaves and inflorescences, and with hairy spikelets" (Whistler, 1988; p. 49).

Description from GrassBase.

Habitat/ecology:  In Fiji," occurs from sea level to about 600 m in coastal thickets, light forest, waste places, pastures, coconut plantations, and old gardens, usually preferring shady places" (Smith, 1979; p. 351). In Samoa and Wallis and Futuna, "common to abundant in coconut plantations and sunny, disturbed places" (Whistler, 1988; p. 49).

Propagation:  Seed

Native range:  Southeastern Asia (Smith, 1979; p. 351).

Presence:

Pacific
Country/Terr./St. & Island group	Location	Cited status & Cited as invasive & Cited as cultivated & Cited as aboriginal introduction?	Reference & Comments
American Samoa Manu‘a Islands	Ofu Island	introduced invasive	Whistler, W. A. (1990) (p. 14) Voucher cited: Yuncker 9486
American Samoa Manu‘a Islands	Ta‘u Island	introduced invasive	Whistler, W. A. (1990) (p. 14) Vouchers cited: Harris 334, Yuncker 9114
American Samoa Manu‘a Islands	Ta‘u Island		National Tropical Botanical Garden (U.S.A. Hawaii. Kalaheo.) (1991) (voucher ID: PTBG 9518) Taxon name on voucher: Cyrtococcum trigonum
Cook Islands Southern Cook Islands	Mangaia Island		McCormack, Gerald (2013)
Cook Islands Southern Cook Islands	Ma‘uke Island		McCormack, Gerald (2013)
Cook Islands Southern Cook Islands	Miti‘aro Island		McCormack, Gerald (2013)
Fiji Fiji Islands	Taveuni Island	introduced invasive abo. intro.	Smith, Albert C. (1979) (p. 351) Vouchers cited: Smith 8118, DA 8908, Smith 8313, DA 8886, DA 8936
Fiji Fiji Islands	Vanua Levu Island	introduced invasive abo. intro.	Smith, Albert C. (1979) (p. 351) Vouchers cited: DA 8814, DA 8828, DA 8860, Degener & Ordonez 14149, DA 9621, DA 12050, DA 16826
Fiji Fiji Islands	Viti Levu Island	introduced invasive abo. intro.	Smith, Albert C. (1979) (p. 351) Vouchers cited: DA 9194, DA 10114, DA 8368
Papua New Guinea Papua New Guinea (eastern New Guinea Island)	Papua New Guinea (eastern New Guinea Island)		Henty, E. E. (1969) (p. 60)
Samoa Western Samoa Islands	Upolu Island		National Tropical Botanical Garden (U.S.A. Hawaii. Kalaheo.) (2002) (voucher ID: PTBG 328) Taxon name on voucher: Cyrtococcum trigonum
Samoa Western Samoa Islands	Western Samoa Islands		Whistler, W. A. (1988) (p. 49)
Wallis and Futuna Wallis and Futuna (Horne) Islands	Wallis and Futuna Islands		Whistler, W. A. (1988) (p. 49)

Pacific Rim
Country/Terr./St. & Island group	Location	Cited status & Cited as invasive & Cited as cultivated & Cited as aboriginal introduction?	Reference & Comments
Indonesia Indonesia	Indonesia (Republic of)	native	U.S. Dept. Agr., Agr. Res. Serv. (2013)
Malaysia Malaysia	Malaysia (country of)	native	U.S. Dept. Agr., Agr. Res. Serv. (2013)

Control:  If you know of control methods for Cyrtococcum trigonum, please let us know.