Andropogon glomeratus (Walt.) B.S.P., Poaceae

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Present on Pacific Islands?  yes

Primarily a threat at high elevations?  no

Risk assessment results:  High risk, score: 14 (Go to the risk assessment)

Other Latin names:  Andropogon marcrourus Michx.

Common name(s): [more details]

English: bushy beardgrass, bushy bluestem, chalky bluestem

Habit:  grass

Description:  Grass, "[c]ulms tufted, robust, flattened and covered with crowded keeled sheaths, 1-1.5 m high in flower; leaf-blades 3-5 mm broad; inflorescence dense, club-shaped, the spathes at first green turning pink; racemes 1.5-3 cm long, villous with whitish or tawny hairs; sessile spikelets 3-4 mm long; awns about 15 mm long." (Adams, 1972; p. 201).

"Habit: Perennial; caespitose. Basal innovations flabellate. Culms erect; 75-150 cm long. Leaf-sheaths keeled; glabrous on surface; outer margin glabrous, or hairy. Ligule a ciliolate membrane. Leaf-blades 2.5-6 mm wide. Inflorescence: Synflorescence compound; paniculate (oblong); dense. Inflorescence composed of racemes; terminal and axillary; subtended by a spatheole; embraced at base by subtending leaf. Spatheole lanceolate; 1.5-3 cm long. Peduncle 0.5-1 cm long; hirsute above. Racemes 2; paired; sinuous; 1.5-3 cm long. Rhachis fragile at the nodes; plumose on surface; plumose on margins. Rhachis internodes filiform. Rhachis internode tip transverse; cupuliform; with simple rim. Spikelets in pairs. Fertile spikelets sessile; 1 in the cluster. Companion sterile spikelets pedicelled; 1 in the cluster. Pedicels filiform; curved; plumose. Steriles spikelets: Companion sterile spikelets represented by barren pedicels. Fertile spikelets: Spikelets comprising 1 basal sterile florets; 1 fertile florets; without rhachilla extension. Spikelets lanceolate; dorsally compressed; 3-4.5 mm long; falling entire; deciduous with accessory branch structures. Spikelet callus pilose; base obtuse; inserted. Glumes: Glumes dissimilar; exceeding apex of florets; firmer than fertile lemma. Lower glume lanceolate; 1 times length of spikelet; membranous; 2-keeled; keeled laterally. Lower glume intercarinal veins absent. Lower glume surface concave. Upper glume lanceolate; membranous; 1-keeled; 1-veined. Upper glume lateral veins absent. Upper glume muticous. Florets: Basal sterile florets barren; without significant palea. Lemma of lower sterile floret lanceolate; hyaline. Fertile lemma lanceolate; hyaline; without keel. Lemma apex lobed; 2 -fid; awned; 1 -awned. Principal lemma awn from a sinus; straight; 10-20 mm long overall. Palea absent or minute. Flower: Anthers 3" (GrassBase).

Habitat/ecology:  Ditches, swamp margins, pastures and other disturbed areas.

Propagation:  Seed

Native range:  Southeastern US and Mexico to northern South America, Greater Antilles, St. Kitts to Martinique.

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	Snow, Neil/Lau, Alex (2010) (pp. 47-48) var. pumilus. Voucher cited: T. Tunison s.n. (BISH 734261)
State of Hawaii Hawaiian Islands	O‘ahu Island	introduced invasive	Snow, Neil/Lau, Alex (2010) (pp. 47-48) var. pumilus. Vouchers cited: A. Lau OISC 002 (BISH), K. Metzler A004 (BISH)K. Kawelo s.n. (BISH 687841), J. Fisher OISC s.n. (BISH 718772)
United States (other Pacific offshore islands) Midway Atoll	Midway Atoll	introduced invasive	Starr, Forest/Martz, Kim/Loope, Lloyd L. (2002) (p. 22) Incorrectly identified as Andropogon virginicus per Snow & Lau, 2010; p. 48. Voucher cited: Starr & Martz 990407-1 (BISH)
United States (other Pacific offshore islands) Midway Atoll	Sand Island	introduced invasive	Snow, Neil/Lau, Alex (2010) (pp. 47-48) var. pumilus. Vouchers cited: J.T. Duncan s.n. (BISH 661392), F. Starr & K. Martz 990407-1 (BISH), C. Corn s.n. (BISH 667024), K. McDermond s.n. (BISH 634271)

Pacific Rim
Country/Terr./St. & Island group	Location	Cited status & Cited as invasive & Cited as cultivated & Cited as aboriginal introduction?	Reference & Comments
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)
El Salvador El Salvador	El Salvador (Republic of)	native	U.S. Dept. Agr., Agr. Res. Serv. (2011)
Guatemala Guatemala	Guatemala (Republic of)	native	U.S. Dept. Agr., Agr. Res. Serv. (2011)
Honduras Honduras	Honduras (Republic 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)
Panama Panama	Panama (Republic of)	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)

Additional information:
Photos and additional information at University of Florida, Center for Aquatic and Invasive Plants

Additional online information about Andropogon glomeratus is available from the Hawaiian Ecosystems at Risk project (HEAR).

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

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

References:

Adams, C. D. 1972. Flowering plants of Jamaica. University of the West Indies, Mona, Jamaica. 848 pp.

Clayton, W. D./Harman, K. T./Williamson, H. 2002. World Grass Species: Descriptions, Identification, and Information Retrieval (online resource).

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.

Snow, Neil/Lau, Alex. 2010. Notes on grasses (Poaceae) in Hawai‘i. In: Evenhuis, Neal L. and Eldredge, Lucias G., eds. Records of the Hawaii Biological Survey for 2008. Bishop Museum Occasional Papers 107:46-60.

Starr, Forest/Martz, Kim/Loope, Lloyd L. 2002. New plant records from the Hawaiian archipelago. In: Evenhuis, Neal L. and Eldredge, Lucius G., eds. Records of the Hawaii Biological Survey for 2000. Part 2: Notes. Bishop Museum Occasional Papers. 69:16-27.

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

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).