Oenothera stricta subsp. stricta Ledeb. ex Link, Onagraceae

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Present on Pacific Islands?  yes

Primarily a threat at high elevations?  yes

Other Latin names:  Oenothera striata Link

Common name(s): [more details]

English: Chilean evening-primrose, common evening primrose, sweet sundrop

Habit:  herb

Description:  "Annual or perhaps sometimes biennial herbs; stems erect or rarely decumbent, 3.5-15 dm long, unbranched or with a few side branches, strigillose, especially below, and sparsely to densely villous and glandular pubescent.  Basal leaves narrowly elliptic to oblanceolate, 10-15 cm long, 0.8-1.3 cm wide, flat or slightly undulate, margins serrate; cauline leaves very narrowly elliptic to lanceolate, 2-10 cm long, 0.6-1.2 cm wide, flat or slightly undulate, margins serrate.  Flowers in the upper leaf axils, 1 to several opening each day per stem near sunset; floral tube 2-4.5 cm long; sepals with distinct tips 1-3 mm long; petals yellow, often with a red  spot at the base, broadly obovate, 1.5-2.5 (-3.5) cm long; pollen ca. 50% fertile; stigma surrounded by anthers at anthesis.  Capsules conspicuously enlarged at apex, 3-4 cm long.  Seeds in 2 rows per cell, ellipsoid, 1.3-1.8 mm long, with a short beak"  (Wagner et al., 1999; p. 1001).

"Herbacée dressée annuelle ou biannuelle atteignant 1 m de hauteur, reconnaissable à ses feuilles lancéolées et poilues, ses fleurs solitaires de couleur jaune, orange ou rouge à 4 pétales et son fruit sec (une capsule) de forme cylindrique" (Meyer, 2008; p. 24).

Habitat/ecology:  In Hawai‘i, "naturalized and relatively common in open sites, especially along roadsides, 1,200-2,740 m" (Wagner et al., 1999; p. 1001). In Australia, "it inhabits roadsides and other disturbed areas, especially on sandy soils" (Auld & Medd, 1987, cited in Csurhes & Edwards, 1998; p. 181).

Propagation:  Seed

Native range:  "Chile and Argentina, South America, now naturalized on all continents except Antarctica" (Wagner et al., 1999; p. 1001).

Presence:

Pacific
Country/Terr./St. & Island group	Location	Cited status & Cited as invasive & Cited as cultivated & Cited as aboriginal introduction?	Reference & Comments
Chile (Rapa Nui Island) Rapa Nui (Easter) Island	Rapa Nui (Easter) Island (Isla de Pasqua)	introduced invasive	Meyer, Jean-Yves (2008) (pp. 24, 29) "Nous l’avons observé abondante en haut de plage sableuse à Ovahe où elle envahit le vestige de végétation littorale indigène à Tetragonia tetragonoides & et Boerhavia acutifolia" (Meyer, 2008; p. 24).
State of Hawaii Hawaiian Islands	Hawai‘i (Big) Island	introduced invasive	Wagner, Warren L./Herbst, Derral R./Sohmer, S. H. (1999) (p. 1001)
State of Hawaii Hawaiian Islands	Maui Island	introduced invasive	Wagner, Warren L./Herbst, Derral R./Sohmer, S. H. (1999) (p. 1001) East Maui. Voucher cited: Forbes 1070.M (BISH)

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	Csurhes, S./Edwards, R. (1998) (p. 181)
Australia Australia (continental)	Northern Territory	introduced invasive	Csurhes, S./Edwards, R. (1998) (p. 181)
Australia Australia (continental)	Queensland	introduced invasive	Csurhes, S./Edwards, R. (1998) (p. 181)
Chile (continental) Chile	Chile (Republic of)	native	Wagner, Warren L./Herbst, Derral R./Sohmer, S. H. (1999) (p. 1001)
Chile (continental) Chile	Chile (Republic of)	native	U.S. Dept. Agr., Agr. Res. Serv. (2009)
New Zealand New Zealand	New Zealand (country)	introduced invasive	Webb, C. J./Sykes, W. R./Garnock-Jones, P. J. (1988) (p. 912) "Behind beaches and in other sandy and stony areas such as river beds, roadsides, railway embankments, and open waste places".

Indian Ocean
Country/Terr./St. & Island group	Location	Cited status & Cited as invasive & Cited as cultivated & Cited as aboriginal introduction?	Reference & Comments
La Réunion (France) La Réunion Island	La Réunion Island	introduced invasive	Lavergne, Christophe (2006) "Naturalisé"

Control: 

Physical:  "La lutte par arrachage manuelle (arrachage des plants) est réalisable mais difficile en raison du sytème racinaire profond" (Meyer, 2008; p. 24).

Chemical:  "La lutte chimique est à proscrire sur la plage sableuse" (Meyer, 2008; p. 24).

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

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

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

Other Latin names:  Oenothera striata Link

References:

Csurhes, S./Edwards, R. 1998. Potential environmental weeds in Australia: Candidate species for preventative control. Canberra, Australia. Biodiversity Group, Environment Australia. 208 pp.

Lavergne, Christophe. 2006. List des especes exotiques envahissantes a La Reunion. Unpublished manuscript (Excel file). .

Meyer, Jean-Yves. 2008. Rapport de mission d'expertise a Rapa Nui du 02 au 11 Juin 2008: Plan d'action strategique pour lutter contre les plantes introduites envahissantes sur Rapa Nui (Île de pâques) [Strategic action plan to control invasive alien plants on Rapa Nui (Easter Island) [unpublished report]. Délégation à la Recherche, Ministère de l'Education, l'Enseignement supérieur et la Recherche, B.P. 20981 Papeete, Tahiti, Polynésie française. 62 pp. .

U. S. Government. 2009. Integrated Taxonomic Information System (ITIS) (on-line resource).

U.S. Dept. Agr., Agr. Res. Serv. 2009. 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).

Webb, C. J./Sykes, W. R./Garnock-Jones, P. J. 1988. Flora of New Zealand, Volume IV: Naturalised pteridophytes, gymnosperms, dicotyledons. Botany Division, DSIR, Christchurch. 1365 pp.