Pacific Island Ecosystems at Risk (PIER)

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Schizachyrium condensatum
(Kunth) Nees, Poaceae
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Present on Pacific Islands?  yes

Primarily a threat at high elevations?  no

Risk assessment results:  High risk, score: 13 (Go to the risk assessment)

Other Latin names:  Andropogon condensatus Kunth

Common name(s): [more details]

English: bush beardgrass, little bluestem

Spanish: aguará ruguay, yerba barbuda

Habit:  grass

Description:  "Perennial [grass]; culms tufted, erect, 9-15 dm tall, unbranched in lower part, repeatedly branching above into a compound inflorescence, internodes 2-3.5 mm in diameter, glabrous, broadly elliptic in cross section, filled with white or pinkish pith, nodes inconspicuous, glabrous.  Sheaths keeled, glabrous, rarely sparsely puberulent; ligule a firm membrane, 0.7-2 mm long, adnate to sheath margins; blades up to 40 cm long, 3-8 mm wide, glabrous, lower surface keeled, occasionally with a few hairs at throat.  Inflorescences loose, composed of numerous solitary racemes subtended by spathes, 20-40 cm long, 3-8 cm wide, branched in upper part, peduncles 2.5-6 cm long, with up to 8 spikelet pairs, individual racemes on slender branches, spathes involute or flattened, somewhat concealing the lower spikelet pairs, 15-35 mm long, rachis internodes 4-6 mm long, widened upward, conspicuously ciliate on the edges, pedicels 3.6-5.5 mm long; sessile spikelets narrowly ovate, 4.5-5 mm long, callus blunt, minutely bearded, hidden by the hollow apex of the rachis internode, glumes subequal, as long as the spikelet, first glume slightly convex on the back, with 2 submarginal keels, apex slightly bidentate, second glume slightly shorter than first glume, 1-nerved, strongly keeled, the keel scabrous, first lemma 3.2-3.8 mm long, hyaline, ciliolate on the margins, apex acute, second lemma hyaline, apex deeply bifid, ciliolate, awned, the awn dark brown and strongly twisted below, the exserted portion above the bend straight or loosely twisted, ca. 10 mm long, palea absent; pedicellate spikelet sterile, usually 1-2 mm long, awn straight, up to 2 mm long.  Caryopsis amber, linear-cylindrical, 2.5-2.8 mm long"  (Wagner et al., 1999; p. 1590).

Description from GrassBase.

Habitat/ecology:  "Wood- and shrubland, grassland, disturbed sites.  This fast growing grass send up new tillers each year from a small root corwn.  The grass is invasive because it promotes the spread of fires and displaces native vegetation with pure stands.  Such stands accumulate laarge quantities of dead and flammable biomass, increasing fire frequency and intensity.  The grass forms dense swards that crowd out native plant species and prevent their regeneration"  (Weber, 2003; p. 391).

In Hawai‘i, "naturalized along roadsides and in open sites in mesic shrubland and grassland, 210-1,310 m" (Wagner et al., 1999; p. 1590); "forms dense stands in disturbed areas of pastures and forests; a fire hazard"  (Motooka et al., 2003).

Propagation:  Seed

Native range:  Tropical and subtropical America.

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. 1590)
Voucher cited: Fosberg 42065 (BISH)
State of Hawaii
Hawaiian Islands
Kaua‘i Island introduced
invasive
Lorence, David H./Flynn, Timothy W./Wagner, Warren L. (1995) (p. 47)
Vouchers cited: L. Hume & R. Levine 411 (PTBG, US), T. Flynn et al. 3547 (BISH, F, MO, MU, NY, OS, PTBG, US), T. Flynn et al. 2717 (PTBG), W.L. Wagner & R. Hanford 6278 (US), T. Flynn et al. 2679 (PTBG)
State of Hawaii
Hawaiian Islands
Kaua‘i Island introduced
invasive
Frohlich, Danielle/Lau, Alex (2012) (p. 45)
Voucher cited: A. Lau & D. Frohlich 2010021701 (BISH)
State of Hawaii
Hawaiian Islands
O‘ahu Island introduced
invasive
Lau, Alex/Frohlich, Danielle (2013) (p. 10)
Voucher cited: J. Beachy US Army 268 (BISH)
Pacific Rim
Country/Terr./St. &
Island group
Location Cited status &
Cited as invasive &
Cited as cultivated &
Cited as aboriginal introduction?
Reference &
Comments
Mexico
Mexico
Mexico (United Mexican States)   Hafliger, Ernst/Scholz, Hildemar (1980) (p. 120)
South America (Pacific rim)
South America (Pacific rim)
Colombia (Republic of) native
U.S. Dept. Agr., Agr. Res. Serv. (2013)
South America (Pacific rim)
South America (Pacific rim)
Perú (Republic of) native
U.S. Dept. Agr., Agr. Res. Serv. (2013)
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
Rivers, Julie (2004) (p. 2)

Control: 

Physical:  "In pastures, grazing management and cultural measures probably more promising"  (Motooka et al., 2003).

Chemical: "Sensitive to glyphosate.  HAVO staff reported control with foliar application of glyphosate at 1% of product in water (Chris Zimmer, HAVO)"  (Motooka et al., 2003).


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

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This page was created on 1 JAN 1999 and was last updated on 1 SEP 2012.