Lamarckia aurea (L.) Moench., Poaceae

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Present on Pacific Islands?  yes

Primarily a threat at high elevations?  no

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

Common name(s): [more details]

English: golden dog's-tail, goldentop, goldentop grass

Habit:  grass

Description:  "Annual. Culms geniculately ascending; 10-15 (-40) cm long. Ligule an eciliate membrane; 5-8 mm long. Leaf-blades 5-20 cm long; 3-7 mm wide. Inflorescence a panicle. Panicle contracted; ovate; secund; 3-6 cm long; gathered into fascicles. Panicle axis bearing deciduous spikelet clusters. Panicle branches pilose. Spikelets subtended by an involucre. Fertile spikelets pedicelled; 1 in the cluster. Companion sterile spikelets pedicelled; 3 in the cluster (and a rudiment). Involucre composed of imperfect spikelets; cuneate; base truncate. Pedicels filiform; pubescent. Sterile spikelets: Companion sterile spikelets well-developed; containing empty lemmas; linear; laterally compressed; 4-8 mm long; longer than fertile; deciduous with the fertile. Companion sterile spikelet glumes membranous; glabrous; entire; acuminate; mucronate, or awned; both glumes awned; with 0.5-1 mm long awn. Companion sterile spikelet lemmas 8-15; exserted from glumes; muticous. Fertile spikelets: Spikelets comprising 1 fertile florets; with diminished florets at the apex. Spikelets ovate; laterally compressed; 3-5 mm long; falling entire; deciduous with accessory branch structures. Glumes similar; exceeding apex of florets; similar to fertile lemma in texture. Lower glume lanceolate; 3-5 mm long; 1 length of upper glume; membranous; without keels; 1 -veined. Lower glume lateral veins absent. Lower glume apex acuminate; mucronate, or awned; 1 -awned. Lower glume awn 1 mm long. Upper glume lanceolate; 3-5 mm long; 1.6 length of adjacent fertile lemma; membranous; without keels; 1 -veined. Upper glume lateral veins absent. Upper glume apex acuminate; mucronate, or awned; 1 -awned. Upper glume awn 1 mm long. Florets: Fertile lemma elliptic; 2.5 mm long; without keel; 5 -veined. Lemma surface scabrous; rough above. Lemma apex dentate; 2 -fid; incised 0.2 of lemma length; awned. Principal lemma awn from a sinus; 6 mm long overall. Palea 1 length of lemma. Apical sterile florets 1 in number; barren; ovate; 0.5 mm long. Apical sterile lemmas awned; 1 -awned. Apical sterile lemma awns 6 mm long. Anthers 3; 0.5 mm long. Caryopsis with adherent pericarp. Hilum elliptic"  (GrassBase, the Online World Grass Flora).

Habitat/ecology:  In Australia, a widespread weed of disturbed areas  (New South Wales Flora Online).

Propagation:  Seed

Native range:  Canary and Madeira Islands, northern Africa, southern Europe and the Middle East; cultivated and 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
State of Hawaii Hawaiian Islands	Maui Island	introduced invasive	Wagner, W. L./Herbst, D. R./Lorence, D. H. (2005) Single collection; Makawao Naturalized
State of Hawaii Hawaiian Islands	Maui Island		Bishop Museum (U.S.A. Hawaii. Honolulu.) (1937) (voucher ID: BISH 119578) Taxon name on voucher: Lamarckia aurea (L.) Moench

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 (2011) Victoria, Tasmania, Western Australia, South Australia
Australia Australia (continental)	New South Wales	introduced invasive	National Herbarium of New South Wales (2011)
Australia Australia (continental)	Queensland	introduced invasive	National Herbarium of New South Wales (2011)
Mexico Mexico	Mexico (United Mexican States)		Clayton, W.D./Harman, K.T./Williamson, H. (2011)
United States (west coast) United States (west coast states)	USA (California)	introduced	U.S. Dept. Agr., Nat. Res. Cons. Serv. (2011)

Also reported from
Country/Terr./St. & Island group	Location	Cited status & Cited as invasive & Cited as cultivated & Cited as aboriginal introduction?	Reference & Comments
United States (continental except west coast) United States (other states)	United States (other states)	introduced	U.S. Dept. Agr., Nat. Res. Cons. Serv. (2011) Arizona, Texas

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

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

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

References:

Bishop Museum (U.S.A. Hawaii. Honolulu.). 1937. Voucher specimen #BISH119578(Hosaka, E.Y. 1831).

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.

National Herbarium of New South Wales. 2011. PlantNet: New South Wales Flora online. The Plant Information Network System of the Botanic Gardens Trust Version 2.0. Online resource.

U. S. Government. 2011. Integrated Taxonomic Information System (ITIS) (on-line resource).

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, W. L./Herbst, D. R./Lorence, D. H. 2005. Flora of the Hawaiian Islands website (online resource).