Leptochloa fusca (L.) Kunth, Poaceae

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Present on Pacific Islands?  yes

Primarily a threat at high elevations?  no

Other Latin names:  Diplachne fusca (L.) P. Beauv. ex Roem. & Schult.; Leptochloa malabarica (L.) Veldkamp; Leptochloa uninervia (J. Presl) Hitchc. & Chase [= Leptochloa fusca subsp. uninervia]

Common name(s): [more details]

Chinese: shuang fu cao

English: Malabar sprangletop, Mexican sprangletop

Spanish: paja gris

Habit:  grass

Description:  "Habit: Perennial. Culms decumbent; 60-150 cm long; rooting from lower nodes. Ligule an eciliate membrane; 3-8 mm long; acute. Leaf-blades flat, or convolute; 25-55 cm long; 3-5 mm wide; stiff; mid-green and grey-green. Leaf-blade midrib widened. Leaf-blade surface scabrous. Leaf-blade apex attenuate. Inflorescence composed of racemes. Racemes 10-30; borne along a central axis; erect; straight; unilateral; 7-15 cm long. Central inflorescence axis 15-30 cm long. Rhachis semiterete. Spikelet packing broadside to rhachis; lax. Spikelets solitary. Fertile spikelets pedicelled, or sessile. Pedicels filiform; 0.5-1.5 mm long.  Spikelets comprising 6-11 fertile florets; with diminished florets at the apex. Spikelets elliptic; laterally compressed; compressed slightly; 8-15 mm long; breaking up at maturity; disarticulating below each fertile floret. Rhachilla internodes eventually visible between lemmas. Floret callus evident; pubescent; obtuse; disarticulating obliquely. Glumes persistent; similar; shorter than spikelet. Lower glume lanceolate; 2.1-4.6 mm long; 0.6-0.7 times length of upper glume; membranous; 1-keeled; 1 -veined. Lower glume primary vein scabrous. Lower glume lateral veins absent. Lower glume apex acute, or acuminate. Upper glume oblong; 3.3-7.4 mm long; 1-1.3 times length of adjacent fertile lemma; membranous; 1-keeled; 1 -veined. Upper glume primary vein scabrous. Upper glume lateral veins absent. Upper glume apex obtuse, or acute; mucronate. Florets: Fertile lemma oblong; 3.2-5.9 mm long; membranous; dark green, or grey; without keel; 3 -veined. Lemma midvein ciliate; hairy below. Lemma lateral veins close to margins. Lemma margins pilose; hairy below. Lemma apex dentate; 2 -fid; mucronate, or awned; 1 -awned. Principal lemma awn from a sinus; 0.3-1.6 mm long overall. Palea 2 -veined. Palea keels scabrous. Palea surface pubescent; hairy on flanks. Apical sterile florets resembling fertile though underdeveloped. Flower: Lodicules 2; cuneate; fleshy. Anthers 3; 0.2-2.7 mm long. Caryopsis with adherent pericarp; ellipsoid; flattened; concavo-convex; 1.6-1.8 mm long"  (GrassBase).

ssp. uninervia (J. Presl) Hitchc. & Chase:  "Annuals; culms tufted, decumbent or erect, 7.5-13  dm tall, branching above base.  Sheaths chartaceous, only loosely clasping culms when older, persistent, glabrous, slightly scabrous, apex prolonged into auricles; ligule 1.5-2 mm long, membranous, truncate, margins entire but often frayed; blades linear, flat or involute, 6-45 cm long, 3-6 mm wide, slightly scabrous.  Inflorescences paniculate, oblong to ovoid, 10-35 cm long, racemes numerous on an elongate axis, branches usually appressed to ascending, rarely spreading; spikelets appressed to the branches, 5-9-flowered, 3-8 mm long, overlapping by 1/3 their length; glumes unequal, ovate to oblong, glabrous, distinctly 1-nerved, the nerve scabrous, apex truncate to acute, finely ciliate, mucronate, first glume 0.8-1.4 mm long, second glume 1.6-2 mm long, occasionally with lateral lobes; lemmas pale green, oblong, 2-2.5 mm long, 3-nerved, margins membranous and appressed-pilose, apex rounded to acute, finely fimbriate, ± mucronate; palea pale green, elliptic to obovate, 2-2.5 mm long, 2-nerved, margins membranous and appressed-pilose, apex acute.  Caryopsis pale brown, obovate, 1-1.2 mm long, dorsally compressed"  (Wagner et al., 1999; p. 1558).

Habitat/ecology:  In Hawai‘i, "naturalized in wet, disturbed places such as along irrigation ditches and in shallow, standing water, 0-580 m" (Wagner et al., 1999; p. 1558).

Propagation:  Seed

Native range:  "Native to the warmer regions of the Americas" (Wagner et al., 1999; p. 1558).

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	Hawai‘i (Big) Island	introduced invasive	Wagner, Warren L./Herbst, Derral R./Sohmer, S. H. (1999) (p. 1558) Ssp. uninervia
State of Hawaii Hawaiian Islands	Kaua‘i Island	introduced invasive	Wagner, Warren L./Herbst, Derral R./Sohmer, S. H. (1999) (p. 1558) Ssp. uninervia
State of Hawaii Hawaiian Islands	Lāna‘i Island	introduced invasive	Oppenheimer, Hank L. (2003) (p. 21) Ssp. uninervia. Voucher cited: Oppenheimer H40121 (BISH)
State of Hawaii Hawaiian Islands	Maui Island	introduced invasive	Herbst, Derral R./Clayton, W. D. (1998) (p. 29) As. Leptochloa uninervia (K. Presl) Hitchc. & Chase
State of Hawaii Hawaiian Islands	Moloka‘i Island	introduced invasive	Wagner, Warren L./Herbst, Derral R./Sohmer, S. H. (1999) (p. 1558) Ssp. uninervia
State of Hawaii Hawaiian Islands	O‘ahu Island	introduced invasive	Wagner, Warren L./Herbst, Derral R./Sohmer, S. H. (1999) (p. 1558) Ssp. uninervia; voucher cited: Herbst 458 (BISH)
Papua New Guinea Papua New Guinea (eastern New Guinea Island)	Papua New Guinea (eastern New Guinea Island)	native	U.S. Dept. Agr., Agr. Res. Serv. (2011)
Philippines Philippine Islands	Philippine Islands	native	U.S. Dept. Agr., Agr. Res. Serv. (2011)
United States (other Pacific offshore islands) Midway Atoll	Midway Atoll	introduced invasive	Starr, Forest/Martz, Kim (2000) (p. 11) As. Leptochloa uninervia (K. Presl) Hitchc. & Chase; voucher cited: Starr & Martz 990507-3

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)	New South Wales	native	U.S. Dept. Agr., Agr. Res. Serv. (2011)
Australia Australia (continental)	Northern Territory	native	U.S. Dept. Agr., Agr. Res. Serv. (2011)
Australia Australia (continental)	Queensland	native	U.S. Dept. Agr., Agr. Res. Serv. (2011)
Cambodia Cambodia	Cambodia (Kingdom of)	native	U.S. Dept. Agr., Agr. Res. Serv. (2011)
Chile (continental) Chile	Chile (Republic of)	native	U.S. Dept. Agr., Agr. Res. Serv. (2011)
China China	China (People's Republic of)	native	U.S. Dept. Agr., Agr. Res. Serv. (2011)
Colombia Colombia	Colombia (Republic of)	native	U.S. Dept. Agr., Agr. Res. Serv. (2011)
Costa Rica Costa Rica	Costa Rica (Republic of)	native	U.S. Dept. Agr., Agr. Res. Serv. (2011)
Ecuador (Mainland) Ecuador	Ecuador (Republic of) (continental)	native	U.S. Dept. Agr., Agr. Res. Serv. (2011)
Honduras Honduras	Honduras (Republic of)	native	U.S. Dept. Agr., Agr. Res. Serv. (2011)
Indonesia Indonesia	Indonesia (Republic of)	native	U.S. Dept. Agr., Agr. Res. Serv. (2011)
Japan Japan	Japan (country)	native	U.S. Dept. Agr., Agr. Res. Serv. (2011)
Japan Japan	Japan (country)	introduced	Mito, Toshikazu/Uesugi, Tetsuro (2004) (p. 192)
Malaysia Malaysia	Malaysia (country of)	native	U.S. Dept. Agr., Agr. Res. Serv. (2011)
Mexico Mexico	Mexico (United Mexican States)	native	U.S. Dept. Agr., Agr. Res. Serv. (2011)
Nicaragua Nicaragua	Nicaragua (Republic of)	native	U.S. Dept. Agr., Agr. Res. Serv. (2011)
Perú Perú	Perú (Republic of)	native	U.S. Dept. Agr., Agr. Res. Serv. (2011)
Taiwan Taiwan	Taiwan Island	native	U.S. Dept. Agr., Agr. Res. Serv. (2011)
Thailand Thailand	Thailand (Kingdom of)	native	U.S. Dept. Agr., Agr. Res. Serv. (2011)
United States (west coast) United States (west coast states)	USA (Oregon)	native	U.S. Dept. Agr., Agr. Res. Serv. (2011)
United States (west coast) United States (west coast states)	USA (California)	native	U.S. Dept. Agr., Agr. Res. Serv. (2011)
United States (west coast) United States (west coast states)	USA (Washington)	native	U.S. Dept. Agr., Agr. Res. Serv. (2011)
Vietnam Vietnam	Vietnam (Socialist Republic of)	native	U.S. Dept. Agr., Agr. Res. Serv. (2011)

Indian Ocean
Country/Terr./St. & Island group	Location	Cited status & Cited as invasive & Cited as cultivated & Cited as aboriginal introduction?	Reference & Comments
British Indian Ocean Territory Chagos Archipelago	Diego Garcia Island	introduced invasive	Whistler, W. Arthur (1996) (p. 24) As Leptochloa uninervia (Presl) Hitchc. & Chase

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

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

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

References:

Cardenas, Juan/Reys, Carlos E./Doll, Jerry D./Pardo, Fernando. 1972. Tropical weeds; malezas tropicales, vol. 1. International Plant Protection Center, Oregon State University, Corvallis. 341 pp.

Clayton, W.D./Harman, K.T./Williamson, H. 2011. World Grass Species: Descriptions, Identification, and Information Retrieval [GrassBase - The Online World Grass Flora]. The Board of Trustees, Royal Botanic Gardens, Kew.

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

Herbst, Derral R./Clayton, W. D. 1998. Notes on the grasses of Hawai‘i: new records, corrections, and name changes. In: Evenhuis, Neal L. and Miller, Scott, E., eds. Records of the Hawaii Biological Survey for 1997. Part 1: Articles. Bishop Museum Occasional Papers. 55:17-38.

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.

Oppenheimer, Hank L. 2003. New plant records from Maui and Hawai‘i Counties. In: Evenhuis, Neal L. and Eldredge, Lucius G., eds. Records of the Hawaii Biological Survey for 2001-2002. Part 1: Articles. Bishop Museum Occasional Papers. 73:3-30.

Starr, Forest/Martz, Kim. 2000. New plant records from Midway Atoll for 1999. In: Evenhuis, Neal L. and Eldredge, Lucius G., eds. Records of the Hawaii Biological Survey for 1999. Part 2: Notes. Bishop Museum Occasional Papers. 64:10-12.

U.S. Dept. Agr., Agr. Res. Serv. 2011. National Genetic Resources Program. Germplasm Resources Information Network (GRIN). Online searchable database.

U.S. Dept. Agr., Nat. Res. Cons. Serv. 2011. The PLANTS Database. National Plant Data Center, Baton Rouge, LA 70874-4490 USA.

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).

Whistler, W. Arthur. 1996. Botanical survey of Diego Garcia, Chagos Archipelago, British Indian Ocean Territory. Isle Botanica. 49 pp.

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