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]

Chinese: dai xiao cao

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

Spanish: amarillo, Don Diego de la noche, flor de San José

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).  "In Chile this species grows in the following environmental conditions:  Low altitude, interior valleys; coastal mountains, 500-2000 m.  Somewhat dry areas where the drought may last 3-5 months, precipitations of 400-800 mm. are concentrated in winter.  Fully exposed to the sun, level areas or slopes facing north"  (Chileflora).

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 (offshore islands) 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. (2011)
China China	China (People's Republic of)	introduced invasive cultivated	Zhengyi, Wu/Raven, Peter H./Deyuan, Hong (2011) Moist, disturbed habitats near streams, roadside ditches, usually escaped from cultivation; 600-2500 m. Fujian, Guangxi, Guizhou, Hubei, Jiangxi, Shaanxi, Shandong, Sichuan, Yunnan.
Indonesia Indonesia	Indonesia (Republic of)	introduced	Zhengyi, Wu/Raven, Peter H./Deyuan, Hong (2011)
Japan Japan	Japan (country)	introduced	Mito, Toshikazu/Uesugi, Tetsuro (2004) (p. 186)
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".
Taiwan Taiwan	Taiwan Island	introduced invasive cultivated	Zhengyi, Wu/Raven, Peter H./Deyuan, Hong (2011) Moist, disturbed habitats near streams, roadside ditches, usually escaped from cultivation; 600-2500 m.

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:
Photos and other information from Chileflora.

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).

References:

Belov, Michail. 2011. Chileflora (online resource).

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. .

Mito, Toshikazu/Uesugi, Tetsuro. 2004. Invasive alien species in Japan: the status quo and the new regulation for prevention of their adverse effects. Global Environmental Research 8(2)/2004: 171-191.

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.

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.

Zhengyi, Wu/Raven, Peter H./Deyuan, Hong. 2011. Flora of China (online resource).