Pacific Island Ecosystems at Risk (PIER)

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Aira caryophyllea
L., Poaceae
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Present on Pacific Islands?  yes

Primarily a threat at high elevations?  yes

Risk assessment results:  Reject, score: 9 (Go to the risk assessment).

Common name(s): [more details]

Chinese: yin xu cao

English: silver hairgrass, silvery hair grass

French: aira caryophyllée, canche caryophyllée

Habit:  grass

Description:  "Annuals; culms solitary or few, sometimes numerous, forming large perennial clumps resulting from reseeding, 3-40 cm tall.  Sheaths glabrous, open to base; ligule membranous, triangular, 4-5 mm long, apex entire but becoming lacerate; blades filiform or subsetaceous, usually 1-5 cm long, up to 1 mm wide.  Inflorescences paniculate, loose, ovate to oblong, 1-12 cm long, the branches bare at base; spikelets 2, ca. 3 mm long, clustered toward tips of capillary branches, pedicels 0.7-3.5 times as long as the spikelet and pear-shaped at apex; glumes pale brown, chartaceous, ovate, 2.3-3.5 mm long, enclosing the florets, nerves ± prominent, surface lustrous, glabrous except sparsely scabrous along keel, apex acute, slightly erose; lemmas dark reddish brown, narrowly ovate, 2-2.5 mm long, short-scabrous, apex acuminate, 2-lobed, apical teeth setaceous, awn 3-4 mm long, slightly geniculate, inserted below midpoint on dorsal face, rarely absent, callus minutely bearded at lateral margins of floret; palea similar in color, vestiture, and texture to lemma, 1.5-2 mm long, apex acuminate, somewhat adnate to caryopsis.  Caryopsis 1-1.5 mm long, ca. 0.5 mm in diameter, weakly adnate to lemma and palea and remaining enclosed within them"  (Wagner et al., 1999; p. 1495).

Description from GrassBase.

Habitat/ecology:  "Coastal vegetation, heath- and woodland, riparian habitats, wetlands, rock outcrops.  In the native range, this grass is found in forests on sandy and generally acid soils that are not too nutrient-poor, in heaths, on rocks and dunes.  It is adapted to nutrient-poor habitats and grows in dense colonies, eliminating native vegetation and preventing the establishment of native plants" (Weber, 2003; p. 33).

In Hawai‘i, "naturalized in pastures and on lava, often near moist areas, and in subalpine shrubland, 1,050-2,440 m"  (Wagner et al., 1999; p. 1495).

Propagation:  Seed

Native range:  Europe, Africa and western Asia (GRIN).

Presence:

Pacific
Country/Terr./St. &
Island group
Location Cited status &
Cited as invasive &
Cited as cultivated &
Cited as aboriginal introduction?
Reference &
Comments
Chile (offshore islands)
Juan Fernández Islands
Isla Más a Tierra (Robinson Crusoe Island) introduced
Skottsberg, Carl (1953) (p. 215)
Rather common in the basal region, more so in the western part.
Chile (offshore islands)
Juan Fernández Islands
Isla Más a Tierra (Robinson Crusoe Island) introduced
invasive
Atkinson, Rachel/Sawyer, John (2011)
Chile (offshore islands)
Juan Fernández Islands
Isla Más a Tierra (Robinson Crusoe Island) introduced
invasive
Danton, Philippe/Perrier, Christophe/Martinez Reyes, Guido (2006) (p. 550)
Chile (offshore islands)
Juan Fernández Islands
Isla Más Afuera (Alejandro Selkirk Island) introduced
Skottsberg, Carl (1953) (p. 215)
Chile (offshore islands)
Juan Fernández Islands
Isla Más Afuera (Alejandro Selkirk Island) introduced
invasive
Atkinson, Rachel/Sawyer, John (2011)
Chile (offshore islands)
Juan Fernández Islands
Isla Más Afuera (Alejandro Selkirk Island) introduced
invasive
Danton, Philippe/Perrier, Christophe/Martinez Reyes, Guido (2006) (p. 550)
Chile (offshore islands)
Juan Fernández Islands
Morro Juanango introduced
invasive
Danton, Philippe/Perrier, Christophe/Martinez Reyes, Guido (2006) (p. 550)
State of Hawaii
Hawaiian Islands
Hawai‘i (Big) Island introduced
invasive
Wagner, Warren L./Herbst, Derral R./Sohmer, S. H. (1999) (p. 1495)
State of Hawaii
Hawaiian Islands
Kaua‘i Island introduced
invasive
Lorence, David H./Flynn, Tim (1997) (p. 11)
Voucher cited: Flynn 5843 (PTBG)
State of Hawaii
Hawaiian Islands
Maui Island introduced
invasive
Wagner, Warren L./Herbst, Derral R./Sohmer, S. H. (1999) (p. 1495)
State of Hawaii
Hawaiian Islands
Moloka‘i Island introduced
invasive
Wagner, Warren L./Herbst, Derral R./Sohmer, S. H. (1999) (p. 1495)
Voucher cited: Munro 374 (BISH)
State of Hawaii
Hawaiian Islands
O‘ahu Island introduced
invasive
Wood, K. R. (2006) (p. 18)
Voucher cited: K. R. Wood & J. Lau 10636 (BISH, PTBG, US)
Pacific Rim
Country/Terr./St. &
Island group
Location Cited status &
Cited as invasive &
Cited as cultivated &
Cited as aboriginal introduction?
Reference &
Comments
Australia
Australia (continental)
Australia (continental) introduced
invasive
U.S. Dept. Agr., Agr. Res. Serv. (2013)
Naturalized
Chile (continental)
Chile
Chile (Republic of) introduced
invasive
U.S. Dept. Agr., Agr. Res. Serv. (2013)
Naturalized
China
China
China (People's Republic of)   Zhengyi, Wu/Raven, Peter H./Deyuan, Hong (2013)
Dry grassy places in mountains; ca. 3600 m. W. Xizang.
Ecuador (Mainland)
Ecuador
Ecuador (Republic of) (continental) introduced
invasive
U.S. Dept. Agr., Agr. Res. Serv. (2013)
Naturalized
Japan
Japan
Japan (country) introduced
Mito, Toshikazu/Uesugi, Tetsuro (2004) (p. 191)
Mexico
Mexico
Mexico (United Mexican States) introduced
Weber, Ewald (2003) (p. 33)
New Zealand
New Zealand
New Zealand (country) introduced
invasive
Edgar, E./Connor, H. (2000) (p. 294)
"Usually in dry, stony, or sandy ground, or in disturbed sites; rarely in damp ground at swamp or lagoon margins; sea level to subalpine".
United States (west coast)
United States (west coast states)
USA (Oregon) introduced
invasive
U.S. Dept. Agr., Agr. Res. Serv. (2013)
Naturalized
United States (west coast)
United States (west coast states)
USA (California) introduced
invasive
U.S. Dept. Agr., Agr. Res. Serv. (2013)
Naturalized
United States (west coast)
United States (west coast states)
USA (Washington) introduced
invasive
U.S. Dept. Agr., Agr. Res. Serv. (2013)
Naturalized
Also reported from
Country/Terr./St. &
Island group
Location Cited status &
Cited as invasive &
Cited as cultivated &
Cited as aboriginal introduction?
Reference &
Comments
Canada (except British Colombia)
Canada
Canada (country) introduced
invasive
U.S. Dept. Agr., Agr. Res. Serv. (2013)
Naturalized
United States (continental except west coast)
United States (other states)
United States (other states) introduced
invasive
U.S. Dept. Agr., Agr. Res. Serv. (2013)
Alabama, Georgia, Mississippi, South Carolina, Virginia
Naturalized

Control: 

Physical:  Small patches may be dug out.

Chemical:  Spray with grass-selective herbicides (Weber, 2003; p. 33).


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This page was created on 14 FEB 2007 and was last updated on 21 DEC 2012.