Eragrostis tenuifolia (A.Rich.) Steud., Poaceae

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Present on Pacific Islands?  yes

Primarily a threat at high elevations?  no

Risk assessment results:  Reject, score: 11 (Go to the risk assessment)

Common name(s): [more details]

English: elastic grass, wiry lovegrass

Habit:  grass

Description:  "Caespitose perennials 17-60 cm high, with weakly glandular foliage and pedicels; culms erect or rarely geniculate, terete upward or compressed, flattened or grooved along one side, glabrous, smooth, faintly striate, sparsely branched or simple, few-noded, nodes glabrous; blades up to 22 cm long and 4 mm wide (flattened), flat or later loosely complicate-involute, long acuminate, very finely pointed, usually pilose, scaberulous on the upper surface and margins or smooth, strongly nerved with ridged primary veins (on the lower surface) and several secondary veins, faintly glandular on the margins, often dark green; ligule ciliate, c. 0.3 mm long; collar glabrous; auricles bearded with soft white hairs up to 2 mm long; leaf sheaths loose, chartaceous with scarious margins, from slightly shorter to longer than the internodes, strongly nerved and keeled, laterally folded especially near the base, ciliate downward on the margins, otherwise glabrous, smooth, faintly glandular along the keel.  Panicle up to 28 cm long and 9 cm wide (though often smaller), open, prominently exserted; peduncle terete or angular, strongly nerved with ridged veins, glabrous, smooth; axis angular, glabrous, smooth, usually channeled or grooved; branches and pedicels angular, glabrous, smooth, with prominent often dark pulvini and glabrous or bearded in the axils with white capillary hairs up to 1.5 mm long; the primary branches up to 8 cm long, divided from the base, usually solitary and approximate to distant along the axis; the pedicels usually 2-8.5 mm long (laterals) and 5-16 mm (terminals), with a solitary sometimes indistinct gland close below the spikelet. Spikelets 5.5-10 mm long, 1.5-2 mm wide, with 7-13 loosely imbricate florets, laterally compressed, maturing from below upward, with deciduous glumes and lemmas, and persistent paleas, usually dark olive-green in colour, the mature spikelets with a characteristic saw-toothed appearance from the divergent tips of the lemmas; rhachilla tough, strongly compressed, glabrous, smooth, flexuose, slender, the internodes 0.5-0.75 mm long.  Glumes unequal or subequal, thinly membranous, glabrous, highly variable in shape; lower 0.5-0.75 mm long, narrowly oblong to lanceolate, smooth, obtusely keeled or rounded on the back, nerveless, subacute to obtuse, entire or with a lateral notch; upper glume 0.75-1 mm long, narrow to ovate-oblong, obtuse or truncate, entire or emarginate, usually 1-nerved, rounded on the back downward or keeled, scaberulous upward on the keel or smooth.  Lemmas (lowest) usually 1.5-2 mm long, thinly membranous, ovate-orbicular to oblong-elliptic (flattened), obtuse to subacute, muticous, glabrous, keeled, scaberulous upward on the keel or smooth, the lateral nerves distinctly closer to the margins than to the midnerve and prominent or faint.  Palea slightly shorter than its lemma, thinly membranous with hyaline margins, obtuse to truncate, scaberulous-ciliolate on the keels. Grain 0.75-1 mm long, more or less quadrangular and in outline oblong, truncate (sometimes obtuse) at apex and base, laterally compressed or sometimes laterally flattened and thin, with a shallow longitudinal furrow along one side, striolate, smooth or sometimes very uneven from hollows and rises, brown, the embryo half as long or somewhat more and prominent  (Dassanayake, 1994; pp. 223-224).

Habitat/ecology:  In Tonga, "uncommon along roadsides and in other disturbed places" (Whistler, 1988; p. 52).  In Papua New Guinea, "mainly a roadside plant; very free-seeding and sometimes troublesome in plantations and cultivation" (Henty & Pritchard, 1975; p. 41). In New Caledonia, "d'introduction apparemment récente; devient abondant autour de Nouméa" (MacKee, 1994; p.60).

A common weed and ruderal in the wet zone in highland and montane elevations from 500-2250 m, especially in forests, tea estates, and patanas" (Dassanayake, 1994; pp. 223-224).

Propagation:  Seed; the gelatinous grains are somewhat adhesive (Henty & Pritchard, 1975; p. 41).

Native range:  Africa, extending to Saudi Arabia, Yemen, India and Sri Lanka; exact native range obscure; widely naturalized (GRIN).

Presence:

Pacific
Country/Terr./St. & Island group	Location	Cited status & Cited as invasive & Cited as cultivated & Cited as aboriginal introduction?	Reference & Comments
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)
Cook Islands Southern Cook Islands	Takutea Island		McCormack, Gerald (2013)
Ecuador (Galápagos Islands) Isabela Group	Isabela Island	introduced invasive	Charles Darwin Foundation (2008)
Ecuador (Galápagos Islands) Isabela Group	Volcán Sierra Negra, Isabela Island	introduced invasive	Charles Darwin Foundation (2008)
Ecuador (Galápagos Islands) San Cristóbal Group	San Cristóbal Island	introduced invasive	Charles Darwin Foundation (2008)
Ecuador (Galápagos Islands) Santa Cruz Group	Santa Cruz Island	introduced invasive	Charles Darwin Foundation (2008)
State of Hawaii Hawaiian Islands	Hawai‘i (Big) Island	introduced invasive	Herbst, Derral R./Clayton, W. D. (1998) (p. 28) Voucher cited: Herbst 9814 (BISH)
State of Hawaii Hawaiian Islands	Kaua‘i Island	introduced invasive	Snow, Neil (2008) (p. 39) Voucher cited: C. Imada 2001-69
State of Hawaii Hawaiian Islands	Lāna‘i Island	introduced invasive	Oppenheimer, Hank (2008) (p. 32) Voucher cited: Oppenheimer H100631 (BISH, PTBG)
State of Hawaii Hawaiian Islands	Maui Island	introduced invasive	Oppenheimer, Hank L. (2004) (p. 15) East Maui. Voucher cited: Oppenheimer H70315 (BISH, PTBG)
State of Hawaii Hawaiian Islands	O‘ahu Island	introduced invasive	Herbst, Derral R./Clayton, W. D. (1998) (p. 28) Voucher cited: Nagata 3796 (BISH)
New Caledonia New Caledonia Archipelago	Île Grande Terre	introduced invasive	Gargominy, Oliver/Bouchet, Philipe/Pascal, Michel/Jaffre, Tanguy/Tourneu, Jean-Christophe (1996) (p. 380) Devient abondante autour de Nouméa.
New Caledonia New Caledonia Archipelago	Île Grande Terre	introduced invasive	Tassin, Jacques (2005)
New Caledonia New Caledonia Archipelago	Île Grande Terre	introduced invasive	MacKee, H. S. (1994) (pp. 59-60)
New Caledonia New Caledonia Archipelago	Île des Pins (Isle of Pines)	introduced invasive	Tassin, Jacques (2005)
New Caledonia New Caledonia Archipelago	Île des Pins (Isle of Pines)	introduced invasive	MacKee, H. S. (1994) (pp. 59-60) Voucher cited: MacKee 15785
Papua New Guinea Papua New Guinea (eastern New Guinea Island)	Papua New Guinea (eastern New Guinea Island)		Henty, E. E. (1969) (p. 96) Throughout the Eastern and Western Highlands, at roadsides.
Papua New Guinea Papua New Guinea (eastern New Guinea Island)	Papua New Guinea (eastern New Guinea Island)	invasive	Henty, E. E./Pritchard, G. H. (1975) (p. 41) Mainly between 700 and 2000 m.
Tonga Tonga Islands	Tonga Islands		Whistler, W. A. (1988) (p. 52)
Vanuatu New Hebrides Islands	Vanuatu (Republic of)		Swarbrick, John T. (1997) (p. 92)

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	introduced invasive	National Herbarium of New South Wales (2013) Naturalised
Australia Australia (continental)	Queensland	introduced invasive	National Herbarium of New South Wales (2013) Naturalised
Indonesia Indonesia	Indonesia (Republic of)		Hafliger, Ernst/Scholz, Hildemar (1980) (p. 76)

Control:  If you know of control methods for Eragrostis tenuifolia, please let us know.