Brassica tournefortii

Life-forms

Classification System: APG IV

Superregnum: Eukaryota
Regnum: Plantae
Cladus: Angiosperms
Cladus: Eudicots
Cladus: Core eudicots
Cladus: Rosids
Cladus: Eurosids II
Ordo: Brassicales

Familia: Brassicaceae
Tribus: Brassiceae
Genus: Brassica
Species: Brassica tournefortii
Name

Brassica tournefortii Gouan
Synonyms

Brassica sisymbrioides (Fisch. ex DC.) Grossh.
Brassica stocksii Hook.f. & Thomson
Brassica tournefortii var. dasycarpa O.E.Schulz
Brassica tournefortii f. dentata O.E.Schulz
Brassica tournefortii var. leiocarpa Maire & Weiller
Brassica tournefortii var. recurvata Bornm.
Brassica tournefortii var. sisymbrioides Fisch. ex DC.
Brassicella cheiranthus sensu Adamson
Eruca erecta Lag.
Erucastrum minutiflorum Pau & Font Quer
Erucastrum tournefortii (Gouan) Link
Sinapis caspica Willd. ex Ledeb.

References

Gouan, A., 1773. Illustrationes et Observationes Botanicae, ad specierum historiam facientes 44, t. 20a.

Links

Koch, M.A. et al. 2019. Brassica tournefortii in BrassiBase Tools and biological resources to study characters and traits in the Brassicaceae. Published online. Accessed: 2019 May 22.
International Plant Names Index. 2019. Brassica tournefortii. Published online. Accessed: May 22 2019.
Govaerts, R. et al. 2019. Brassica tournefortii in Kew Science Plants of the World online. The Board of Trustees of the Royal Botanic Gardens, Kew. Published online. Accessed: 2019 May 22. Reference page. as Coincya tournefortii (Gouan) Alcaraz, T.E.Díaz, Rivas Mart. & Sánchez-Gómez (1989)
Tropicos.org 2019. Brassica tournefortii. Missouri Botanical Garden. Published online. Accessed: 22 May 2019.
USDA, ARS, National Genetic Resources Program. Germplasm Resources Information Network - (GRIN) [Online Database]. [1]

Vernacular names
العربية: كرنب تورنفورتي
English: Asian mustard, African mustard, Sahara Mustard
español: Mostaza asiática, Mostaza africana, Mostaza del Sahara
suomi: Välimerenkaali

Brassica tournefortii is a species of plant known by the common names Asian mustard,[1] pale cabbage,[2] African mustard, and Sahara mustard, and is well known as an invasive species, especially in California.

The plant is generally similar to other mustards, but the yellow flowers are not as bright and flashy as closely related species. It is a spreading annual herb with long stems up to 100 centimetres (40 inches) in length.

Description
Leaves of B. tournefortii

This mustard is native to the deserts of North Africa and the Middle East. It became notorious during the twentieth century after it invaded the deserts of the United States and Mexico. Recently it has become an abundant weed of low deserts including the Sonoran and Mojave Deserts, plus the desert valleys such as the Coachella and Imperial Valleys of southern California.[3] The plant disperses easily at the first hint of rain. When the seed coats are moistened they form a gel and become very sticky and readily adhere to people, animals, and objects. Seeds easily take hold along roadsides and arid desert lands, especially in disturbed habitats. The plant disperses 750 to 9000 seeds which stay viable for several years in soil, contributing to its status as an invasive species.[4][5]
As an invasive species

Thick stands of the plant can crowd out native flora. Well-adapted to desert life, it monopolizes any moisture in the soil before other plants can get it and forms seeds before other species do. It is particularly an issue in desert farms when the land is tilled.[4]

It produces seed as early in the year as January, especially if the region undergoes a warm spell, which is a common occurrence during southern California winters. It self-fertilizes and drops seeds into the soil, where they persist, survives fires, and long periods without rain. The fact that it propagates by leaving large numbers of viable seeds in the soil prevents eradication measures such as pulling, mowing, grazing and burning. Individual plants have the capacity to separate from the ground and become like tumbleweeds, dropping seeds as they are carried across the desert floor in the breeze.[3]
Effects on flora

B. tourneforii outcompetes native plants and monopolizes resources before other plants can acquire them, effectively starving out the competition. The plant also inhibits growth of competition by exhibiting an allelopathic effect on surrounding plants, inhibiting their growth.[6]
Controlling the species

Methods of control currently lack biological control, instead physical and preventative measures are taken. Studies are being done that suggests the plant may be controlled using allelopathic methods. One study suggests that there are two factors that affect the dormancy of B. tournefortii: one for the removal of the seed coat and another for darkness. The study showed that when the seed coat was removed using NaOCl and placed in dark conditions, germination was increased. This requirement for darkness indicates that B. tournefortii may be less of an issue in farmland where the ground is untilled.[4]

The seeds of B. tournefortii are highly sensitive to certain germination stimulants released by burning vegetation, collectively known as karrikins.[7] Duplication and subsequent evolution of genes encoding the karrikin receptor protein in the B. tournefortii genome is thought to contribute the increased sensitivity to karrikins.[8] In turn, this trait may have enhanced this species' ability to invade after fire events. Control of this species may be improved by exploiting this trait through chemical stimulation of germination, with the aim of clearing the soil seed bank followed by herbicidal applications or physical removal.
Invasive range

B. tournefortii invades sandy soil, particularly deserts. Notably in areas such as Southern California, Northern and Southern Australia, Saharan Africa, Mexico, etc.[4][6][5]
Economic impact

B. tournefortii occupies the 6th position in the national ranking in terms of revenue loss (AU$10.6 million) due to crop yield losses in Australia.[4][6]
References

USDA, NRCS (n.d.). "Brassica tournefortii". The PLANTS Database (plants.usda.gov). Greensboro, North Carolina: National Plant Data Team. Retrieved 10 January 2016.
BSBI List 2007 (xls). Botanical Society of Britain and Ireland. Archived from the original (xls) on 2015-06-26. Retrieved 2014-10-17.
Dremann, Craig. 2005. California desert and adjacent States Megatransect Survey for the Saharan Mustard, mile-by-mile. Notebooks 192-197 unpublished. http://www.ecoseeds.com/mustards.html.
Mahajan, G.; Mutti, N. K.; Jha, P.; Walsh, M.; Chauhan, B. S. (2018). "Evaluation of dormancy breaking methods for enhanced germination in four biotypes of Brassica tournefortii". Scientific Reports. 8: 17103. doi:10.1038/s41598-018-35574-2.
Abd El-Gawad, A. M. (2014). "Ecology and allelopathic control of Brassica tournefortii in reclaimed areas of the Nile Delta, Egypt". Turkish Journal of Botany. 38: 347–357. doi:10.3906/bot-1302-29.
Mobli, A.; Manalil, S.; Khan, A. M.; Jha, P.; Chauhan, B. S. (2020). "Effect of emergence time on growth and fecundity of Rapistrum rugosum and Brassica tournefortii in the northern region of Australia". Scientific Reports. 10: 15979. doi:10.1038/s41598-020-72582-7. PMC 7524807.
Long, Rowena L.; Stevens, Jason C.; Griffiths, Erin M.; Adamek, Markus; Gorecki, Marta J.; Powles, Stephen B.; Merritt, David J. (October 2011). "Seeds of Brassicaceae weeds have an inherent or inducible response to the germination stimulant karrikinolide". Annals of Botany. 108 (5): 933–944. doi:10.1093/aob/mcr198. PMC 3177676.
Sun, Yueming Kelly; Yao, Jiaren; Scaffidi, Adrian; Melville, Kim T.; Davies, Sabrina F.; Bond, Charles S.; Smith, Steven M.; Flematti, Gavin R.; Waters, Mark T. (December 2020). "Divergent receptor proteins confer responses to different karrikins in two ephemeral weeds". Nature Communications. 11 (1): 1264. doi:10.1038/S41467-020-14991-W. PMC 7062792.