Pacific Island Ecosystems at Risk (PIER)

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Hordeum murinum
L., Poaceae
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Present on Pacific Islands?  yes

Primarily a threat at high elevations?  no

Common name(s): [more details]

English: bulbous barley, false barley, farmer's-foxtail, mouse barley, wall barley, way barley

French: orge des rats, orge queue de souris

Japanese: mugi-kusa

Spanish: cebada ratonera, cebadilla, cola de zorro, espigadilla

Habit:  grass

Description:  "Habit: Annual; caespitose. Culms 6-60 cm long; 3-5-noded. Leaf-sheath oral hairs lacking. Leaf-sheath auricles falcate. Ligule an eciliate membrane; 0.5-1 mm long. Leaf-blades 2-20 cm long; 2-8 mm wide. Inflorescence composed of racemes. Racemes 1; single; linear, or oblong; bilateral; 4-12 cm long. Rhachis fragile at the nodes; flattened. Spikelet packing broadside to rhachis. Rhachis internodes oblong; 3-3.5 mm long; falling with spikelet above. Spikelets in threes. Fertile spikelets sessile; 1 in the cluster. Companion sterile spikelets pedicelled; 2 in the cluster. Pedicels oblong. Sterile spikelets: Companion sterile spikelets well-developed; containing empty lemmas, or male; lanceolate; dorsally compressed; 7-11 mm long; as long as fertile; deciduous with the fertile. Companion sterile spikelet glumes subulate; 16-30 mm long; eciliate on margins, or ciliate on margins. Companion sterile spikelet lemmas 1; exserted from glumes; 7-11 mm long; 1-awned; with 10-40 mm long awn. Fertile spikelets: Spikelets comprising 1 fertile florets; without rhachilla extension. Spikelets lanceolate; dorsally compressed; 7-12 mm long; falling entire; deciduous with accessory branch structures. Glumes: Glumes collateral; similar; gaping. Lower glume subulate; 25-30 mm long; 1 times length of upper glume. Lower glume margins ciliate. Upper glume subulate; 25-30 mm long. Upper glume margins ciliate. Florets: Fertile lemma lanceolate; 7-12 mm long; coriaceous; without keel; 5 -veined. Lemma surface scabrous; rough above. Lemma apex acuminate; awned; 1 -awned. Principal lemma awn 18-50 mm long overall; limb scabrous. Flower: Anthers 3; 0.7-1.2 mm long. Ovary pubescent on apex. Fruit: Caryopsis with adherent pericarp; ellipsoid; sulcate on hilar side; hairy at apex. Embryo 0.2 times length of caryopsis. Hilum linear; 1 times length of caryopsis"  (World Grass Species).

subspecies leporinum Link:  "Pale green annuals; culms geniculate to erect, (1-) 2-4 (-6) dm tall.  Sheaths glabrous or sometimes pilose; ligule 0.5-1 mm long, truncate, erose, ciliolate; blades flat, 2-5 mm wide, glabrous to pilose, auricles well-developed, up to 3.5 mm long.  Inflorescences composed of erect spikes 4-7 (-10) cm long (excluding awns), ± partially enclosed by the sheath, rachis readily disarticulating, the segments (1.5-) 2-3 mm long; spikelets well-developed, the central spikelet sessile, rachilla joints 1-2 mm long, equaling or exceeding pedicels of lateral spikelets, the lateral spikelets usually staminate; glumes 15-22 (-28) mm long, those of the central spikelet and the second glume of the lateral spikelet narrowly lanceolate, 3-nerved, the nerves scabrous, margins ciliate, the first glume of the lateral spikelet awn-like and somewhat longer than glumes of the central floret, scabrous; lemma of central spikelet (6-) 7-9 mm long, glabrous, 5-nerved, the nerves faint, lemmas of lateral spikelets somewhat larger than those of central floret, 7-10 mm long, sterile, lemmas of all spikelets tapering to awns 18-30 mm long; palea lanceolate, 11-12 mm long, 2-nerved, long-pilose and membranous between the nerves and at the margins, folded, evenly appressed long-pilose, apex obtuse to rounded.  Caryopsis reddish brown, oblong, 3-4 cm long, apex densely reddish brown long-pubescent"  (Wagner et al., 1999; p. 1552).

Habitat/ecology:  "Deserts and desert scrub, arid grassland.  A native of dry grassland and disturbed places with three subspecies within the native range.  The grass is invasive because it forms dense swards that displace native grasses and forbs by competing for water, nutrients and space.  The grass is highly competitive to native annuals in arid areas"  (Weber, 2003; p. 203).

In Hawai‘i, "naturalized in moderately moist places such as pastures and abandoned fields, (0-) 30-2,440 m"  (Wagner et al., 1999; p. 1552).

Propagation:  Seed

Native range:  Europe, northern Africa, Asia to India; 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
Australia (Pacific offshore islands)
Lord Howe Island
Lord Howe Island introduced
invasive
Orchard, Anthony E., ed. (1994) (p. 23)
Subsp. glaucum (Steud.) Tzvelev. "An introduced weed". Voucher cited: L.M. Bingley 27 (K). Subsp. leporinum (Link) Arcang. Voucher cited: A.C. Beauglehole 5433 (CANB, MEL)
Australia (Pacific offshore islands)
Norfolk Islands
Norfolk Island introduced
invasive
Orchard, Anthony E., ed. (1994) (p. 12)
Subsp. glaucum (Steud.) Tzvelev. "An introduced weed". Vouchers cited: 1962, P. Ralston (CHR); W.R. Sykes NI 76 (CHR). Subsp. leporinum (Link) Arcang. Vouchers cited: F.C. Allen (CHR), 135 F.C. Allen 221 (CHR)
Chile (offshore islands)
Rapa Nui (Easter) Island
Rapa Nui (Easter) Island (Isla de Pasqua) introduced
Skottsberg, Carl (1953) (p. 80)
Chile (offshore islands)
Juan Fernández Islands
Isla Más a Tierra (Robinson Crusoe Island) introduced
Skottsberg, Carl (1953) (p. 216)
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. 554)
Chile (offshore islands)
Juan Fernández Islands
Isla Más Afuera (Alejandro Selkirk Island) introduced
Skottsberg, Carl (1953) (p. 216)
Coast and mountains.
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. 554)
Chile (offshore islands)
Juan Fernández Islands
Isla Santa Clara introduced
Skottsberg, Carl (1953) (p. 216)
Chile (offshore islands)
Juan Fernández Islands
Isla Santa Clara introduced
invasive
Atkinson, Rachel/Sawyer, John (2011)
Chile (offshore islands)
Juan Fernández Islands
Isla Santa Clara introduced
invasive
Danton, Philippe/Perrier, Christophe/Martinez Reyes, Guido (2006) (p. 554)
Chile (offshore islands)
Juan Fernández Islands
Morro El Verdugo introduced
invasive
Danton, Philippe/Perrier, Christophe/Martinez Reyes, Guido (2006) (p. 554)
Chile (offshore islands)
Juan Fernández Islands
Morro Juanango introduced
invasive
Danton, Philippe/Perrier, Christophe/Martinez Reyes, Guido (2006) (p. 554)
State of Hawaii
Hawaiian Islands
Hawai‘i (Big) Island introduced
invasive
Wagner, Warren L./Herbst, Derral R./Sohmer, S. H. (1999) (p. 1552)
ssp. leporinum Link; voucher cited: Rock 3198 (BISH)
State of Hawaii
Hawaiian Islands
Lāna‘i Island introduced
invasive
Wagner, Warren L./Herbst, Derral R./Sohmer, S. H. (1999) (p. 1552)
ssp. leporinum Link
State of Hawaii
Hawaiian Islands
Maui Island introduced
invasive
Wagner, Warren L./Herbst, Derral R./Sohmer, S. H. (1999) (p. 1552)
ssp. leporinum Link
Philippines
Philippine Islands
Philippine Islands   Hafliger, Ernst/Scholz, Hildemar (1980) (p. 87)
United States (other Pacific offshore islands)
Midway Atoll
Midway Atoll introduced
invasive
Wagner, Warren L./Herbst, Derral R./Sohmer, S. H. (1999) (p. 1552)
ssp. leporinum Link
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
National Herbarium of New South Wales (2013)
As Hordeum murinum subsp. glaucum (Steud.) Tzvelev = Hordeum glaucum and Hordeum murinum subsp. leporinum (Link) Arcang. = Hordeum leporinum
Naturalized
Canada (British Colombia)
Province of British Columbia
Canada (British Columbia) introduced
U.S. Dept. Agr., Nat. Res. Cons. Serv. (2013)
Chile (continental)
Chile
Chile (Republic of) introduced
invasive
U.S. Dept. Agr., Agr. Res. Serv. (2013)
Naturalized
Guatemala
Guatemala
Guatemala (Republic of) introduced
invasive
U.S. Dept. Agr., Agr. Res. Serv. (2013)
Naturalized
Japan
Japan
Japan (country) introduced
invasive
U.S. Dept. Agr., Agr. Res. Serv. (2013)
Naturalized
Japan
Japan
Japan (country) introduced
Mito, Toshikazu/Uesugi, Tetsuro (2004) (p. 192)
Mexico
Mexico
Mexico (United Mexican States) introduced
invasive
U.S. Dept. Agr., Agr. Res. Serv. (2013)
Naturalized
New Zealand
New Zealand
New Zealand (country) introduced
invasive
U.S. Dept. Agr., Agr. Res. Serv. (2013)
Naturalized
Perú
Perú
Perú (Republic of) introduced
invasive
U.S. Dept. Agr., Agr. Res. Serv. (2013)
Naturalized
United States (west coast)
United States (west coast states)
USA (Oregon) introduced
U.S. Dept. Agr., Nat. Res. Cons. Serv. (2013)
United States (west coast)
United States (west coast states)
USA (California) introduced
U.S. Dept. Agr., Nat. Res. Cons. Serv. (2013)
United States (west coast)
United States (west coast states)
USA (Washington) introduced
U.S. Dept. Agr., Nat. Res. Cons. Serv. (2013)
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
U.S. Dept. Agr., Nat. Res. Cons. Serv. (2013)
United States (continental except west coast)
United States (other states)
United States (other states) introduced
U.S. Dept. Agr., Nat. Res. Cons. Serv. (2013)

Control: 

Physical:  Hand pull scattered plants.

Chemical:  Spray with a grass-selective herbicide (Weber, 2003; p. 203).


Need more info? Have questions? Comments? Information to contribute? Contact PIER! (pier@hear.org)

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This page was created on 10 FEB 2007 and was last updated on 8 MAY 2013.