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Rapistrum rugosum (L.) All.

Overview
General Information
ID Info
Similar Species
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Aperçu
Renseignements Généraux
Informations D'identification
Espèces Semblables
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Family :

Famille :

Brassicaceae

Synonym(s) :

Synonyme(s) :

Myagrum rugosum L. (FNA 1993+; USDA-ARS 2024)

Rapistrum hispanicum (L.) Crantz (FNA 1993+; POWO 2024)

Common Name(s) :

Nom(s) commun(s) :

Bastard-cabbage

(English) (FNA 1993+; Wiersema & León 2016; USDA-ARS 2024)
Ball-turnip (English) (Wiersema & León 2016; USDA-ARS 2024)
Turnipweed (English) (Wiersema & León 2016; USDA-ARS 2024)
Giant mustard (English) (Wiersema & León 2016; USDA-ARS 2024)
Rapistre rugueux (French) (Brouillet et al. 2010+)
Håretknopskulpe (Danish) (Wiersema & León 2016)
Gewöhnlicher runzliger Rapsdotter (German) (Wiersema & León 2016; USDA-ARS 2024)

Rapistrum rugosum seeds

  • Rapistrum rugosum seeds

  • Rapistrum rugosum silicle segments

  • Rapistrum rugosum seeds

  • Rapistrum rugosum seed

  • Rapistrum rugosum seeds, fruit, and fruit segment

  • Rapistrum rugosum silicle

  • Rapistrum rugosum silicle segments with seeds

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Overview

Aperçu

Regulation :

Remarques Réglementation:

    Regulation Notes:

    Distribution :

    Répartition :

    Rapistrum rugosum is native to Macaronesia, all throughout the Mediterranean countries to Central Asia and Iran, and northeast Tropical Africa to the Arabian Peninsula (POWO 2024). It has been introduced throughout Europe, the United States, Mexico, temperate South America, South Africa, Japan, Korea, Australia, and Tasmania (POWO 2024).

    In Canada, Rapistrum rugosum is only considered ephemerally present in Ontario and Quebec (Brouillet et al. 2010+).

    In the United States, Rapistrum rugosum is reported in Oregon, California, Nevada, New Mexico, Texas, Louisiana, South Carolina, Tennessee, Missouri, Illinois, Wisconsin, Indiana, Pennsylvania, New York, New Jersey, and Massachusetts (USDA-NRCS 2024).

    Habitat and Crop Association :

    Habitat et Cultures Associées :

    Rapistrum rugosum is a weedy species that inhabits disturbed areas, roadsides, waste places, grasslands, and agricultural fields and can be found from sea level to 2000m. It also contaminates ballast water (FNA 1993+) and spreads via contaminated grass seed and mulching materials (Texas Invasives 2024).

    Rapistrum rugosum is known to infest cereal crops, including Hordeum vulgare L. (barley) and Triticum aestivum L. (wheat) (Heap, 2024). Mowing can reduce flowering and seed formation, although removal of the taproot is best (Texas Invasives 2024).

    Chemical control is challenging because it can quickly develop herbicide resistance (Texas Invasives, 2024). It is documented to have herbicide resistance to chlorsulfuron, imazamox, imazapyr, bispyribac-sodium, florasulam, flucarbazone-Na, iodosulfuron-methyl-Na, and tribenuron-methyl, first reported in Australia, Iran and Spain (Heap 2024).

    Economic Use, cultivation area, and Weed Association :

    Utilisation économique, zone de culture et association de mauvaises herbes :

    Rapistrum rugosum is an edible wild plant that can be eaten raw, but the hairy leaves are bland in flavour and are best cooked as a potherb or stir-fries. For best results, the stems and leaves should be harvested when young; cooking will remove the bitter flavour and the hairs on the leaves.

    Rapistrum rugosum is currently being investigated in its native Tunisia in northern Africa for its medicinal potential. It has been found to contain antioxidant and anti-acetylcholinesterase compounds (Amel et al. 2013). Since it is a safe wild edible, it is presumed safe to ingest medicinally, although its effectiveness will require additional testing.

    Duration of Life Cycle :

    Durée du cycle vital:

    Annual

    Dispersal Unit Type :

    Type d’unité de dispersion :

    Silicle and seed

    General Information

    RENSEIGNEMENTS GÉNÉRAUX

    Rapistrum rugosum is an opportunistic annual that germinates from seed in late fall or early winter in the southern end of its range where it develops a broad mass of basal leaves that smother and outcompete native species and sometimes form monocultures. While mostly found in disturbed sites, it has also been documented as spreading to open forests and riparian areas throughout Texas (Texas Invasives 2024), where it is considered the most invasive in North America.

    It was first collected in North America in 1873 from a ballast in Boston, Massachusetts (FNA 1993+).

    Since chemical control is largely ineffective, studies have been done in Texas, where researchers densely sowed native species with matching competitive characteristics that have been highly effective. One study using the lovely Gaillardia pulchella Foug. of the Asteraceae family over established Rapistrum rugosum seedlings reduced their above-ground productivity by 72% with a roughly 83% reduction in seed set and no significant suppression of nearby native species (Simmons 2005), showing that biological control by these means can be highly effective.

    .

    Rapistrum rugosum infestation. Photo by Karan A. Rawlins, University of Georgia, Bugwood.org

    Identification

    Identification

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    >

    • Silicle segment proximal to stem (lower segment)

      Size

      • Silicle proximal segment size:
        • Length: 0.7–3 mm; width: 0.5–1.5 mm (FNA 1993+)
        • Length: 2–3 (-3.5) mm; width: 1.5 mm (FOP 2024)
        • Length: 3 mm; width: 1.5 mm (PlantNET 2024)

      Shape

      • Proximal silicle segment is cylindrical or inflated oval shaped with truncate ends
      • The end attached to the distal segment may end in a shallow V-shaped notch

      Surface Texture

      • Silicle segment has several longitudinal ridges
      • The outline of 2 valves can be seen on the surface
      • The proximal silicle segment walls are thinner than the distal segment

      Colour

      • Silicle is straw yellow or light brown, may have a purplish wash

      Other Features

      • Silicle segment may be sterile, or 1- 2 seeded (Cousens et al. 1994; PlantNET 2024)
      • Proximal silicle segment will remain attached to the plant when mature (Cousens et al. 1994)

      Rapistrum rugosum silicle segments with seeds

    • Silicle segment distal to stem (terminal segment)

      Size

      • Silicle distal segment size:
        • Length: 1.5–3.5 mm; width: 1–2.8 mm (FNA 1993+)
        • Diameter: 3 mm (FOP 2024)
        • Length: 3–6 mm; width: 3–4 mm (PlantNET 2024)
        • Persistent style length: 1-4 mm (FOP 2024)

      Shape

      • Distal silicle segment is globose or oval shaped, narrowing abruptly into a ridged style remnant

      Surface Texture

      • Distal silicle segment has several thick longitudinal ribs, the fruit coat is thin and translucent between them
      • Each surface rib has irregular, longitudinal wrinkles and ridges
      • Surface may be hairless, or pubescent with short, stiff hairs

      Colour

      • Silicle is straw yellow or light brown, may have a purplish wash

      Other Features

      • Distal silicle segment will separate and fall away from the proximal segment when mature (Cousens 1994)
      • Distal segment contains 1 seed (Cousens et al. 1994; PlantNET 2024)
      • Distal silicle segment has a thicker fruit wall than the proximal silicle segment (Cousens et al. 1994)
      • Distal segment will eventually split open with weathering (Cousens et al. 1994; Chauhan et al. 2006)

      Rapistrum rugosum silicle segments

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    >

    • Seed

      Size

      • Seed size from literature:
        • Length: 1.5–2.5 mm (FNA 1993+)
        • Length: 1.7-2 mm; width: 1.3-1.5 mm (Bojňanský and Fargašová 2007)
        • Length: 2 mm; width: 1.5 mm (Idan 2018)

      Shape

      • Seeds are oval or narrow oval shaped, compressed
      • Radicle protrudes past hilum end

      Surface Texture

      • Seed surface wrinkled longitudinally
      • Outline of radicle visible

      Colour

      • Seed reddish-brown colour
      • Hilum end with black spot

      Other Features

      • Seed is easily damaged and oily

      Rapistrum rugosum seeds

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    >

    • Embryo

      Size

      • Embryo fills the seed

      Shape

      • Embryo bent

      Endosperm

      • Nutritive tissue stored in the cotyledons

      Other Features

      • Cotyledons thin, folded

    Identification Tips

    CONSEILS POUR L’IDENTIFICATION

    The silicles in the Rapistrum genus are composed 2 segments, one that remains attached to the stem (proximal segment), that is 1-3 seeded and generally dehiscent (FNA 1993+; FOP 2024). The distal, or terminal segment is 1-seeded, indehiscent, with a persistent style, and separates from the fruit at maturity (FNA 1993+; FOP 2024).

    R. rugosum fruits can be distinguished by the strongly inflated, subglobose or oval terminal segment that has a longer style remnant than the other species in the genus, R. perenne. The seeds of the 2 species appear similar, with R. rugosum seeds generally smaller (Bojňanský and Fargašová 2007), and would be difficult to distinguish without the fruits.

    Rapistrum rugosum silicle

    Additional Botany Information

    AUTRES RENSEIGNEMENTS BOTANIQUES

    Flowers/Inflorescence

    • Flowering from Apr-July or Nov-June in Texas (FNA 1993+).
    • Flowers in branched, panicle-like racemes with flowers at the tips and maturing fruits located below.
    • Sepals 2.5–5 mm (FNA 1993+).
    • Petals clawed (WFO 2024); pale yellow; 6–11 × 2.5–4 mm (FNA 1993+). 
    • Stamens filaments 4–7 mm; anthers 1.2–1.5 mm (FNA 1993+). 
    • Style slender, 1–3(–5) mm (FNA 1993+; WFO 2024); style tip is persistent in fruit; stigma 2-lobed, broader than the style tip (WFO 2024).
    • Fruiting stalks (pedicels) short, slender or stout, erect-appressed to the main axis (rachis); 1.5–5 mm (FNA 1993+; WFO 2024).

    Vegetative Features

    • Annual herbs 35 – 100 cm tall, usually widely spreading branching from the base (WFO 2024).
    • Stems (10–)20–100(–150) cm long; stiff-hairy (hispid) close to the base, becoming hairless towards tips (FNA 1993+).
    • Basal leaves (2-)5-15(-25) cm long on 1-5 cm leaf stalk (petiole); with (1-)2-3(-5) pairs of lobes on each side, lyrate-pinnatipartite; lateral lobes egg-shaped-triangular, obtuse, with irregularly toothed margins (incise-dentate); terminal lobe large, egg-shaped, square-toothed (dentate), with rough, stiff hairs (hispid) (FNA 1993+; WFO 2024). 
    • Upper leaves simple, lance-shaped, or wavy-lobed (sinuately-lobed); margins dentate or nearly entire (FNA 1993+; WFO 2024); base wedge-shaped (cuneate); sparsely soft short-hairy (puberulous) or hairless on the upper surface (WFO 2024).

    Rapistrum rugosum plant with flowers showing widely-spreading branches and racemes, lobed leaves. Photo by Karan A. Rawlins, University of Georgia, Bugwood.org

    Similar Species

    ESPÈCES SEMBLABLES

    Similar species are based on a study of seed morphology of various species, and those with similar dispersal units are identified. The study is limited by physical specimen and literature availability at the time of examination, and possibly impacted by the subjectivity of the authors based on their knowledge and experience. Providing similar species information for seed identification is to make users aware of similarities that could possibly result in misidentification.

    Rapistrum perenne (L.) All.

    This biennial or perennial species is native to Europe (FNA 1993+). The seeds of R. perenne are generally larger (length: 2.3-2.7 mm; width: 1.8-2 mm, Bojňanský and Fargašová 2007), and the silicle distal segment is long oval shaped, with smooth, longitudinal ribs gradually narrowing to a short style remnant, compared to the distal segment of R. rugosum, with an inflated shape and wrinkled ribs abruptly narrowing to a long style remnant.

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    Reference(s)

    Référence(s)

    Amel, O. H., Malek, B. H., Hichem, B. J., Ali, L., Mahjoub, A., & Boulbaba, S. 2013. Antioxidant and anti-acetylcholinesterase activities of extracts from Rapistrum rugosum in Tunisia. Asian Pacific Journal of Tropical Disease, 3(5), 367-374. https://doi.org/10.1016/S2222-1808(13)60086-9

    Bojňanský, V. and Fargašová, A. 2007. Atlas of Seeds and Fruits of Central and East-European Flora: The Carpathian Mountains Region. Springer, Dordrecht, The Netherlands. 1046 pp.

    Brouillet, L., Coursol, F., Meades, S. J., Favreau, M., Anions, M., Bélisle, P. and Desmet, P. 2010+. VASCAN, the database of vascular plants of Canada. http://data.canadensys.net/vascan/ Accessed April 09, 2024.

    Chauhan, B.S., Gill, G. and Preston, C. 2006. Factors affecting turnipweed (Rapistrum rugosum) seed germination in southern Australia. Weed Science 54: 1032–1036.

    Cousens, R., Armas, G. and Baweja, R. 1994. Germination of Rapistrum rugosum (L.) All. from New South Wales, Australia. Weed Research 4: 127-135.

    Flora of North America (FNA) Editorial Committee, eds. 1993+. Flora of North America North of Mexico [Online]. 22+ vols. New York and Oxford. http://beta.floranorthamerica.org Accessed April 09, 2024.

    Flora of Pakistan (FOP). 2024. Rapistrum rugosum. http://www.efloras.org/florataxon.aspx?flora_id=5&taxon_id=242417123 Accessed July 30, 2024.

    Heap, I. 2024. The International Herbicide-Resistant Weed Database. Online. Available www.weedscience.org Accessed April 09, 2024.

    Idan, G.R. 2018. Comparative Taxonomical Study of three different Wild Species from the Family Brassicaceae in Iraq. Plant Archives 18: 947-952.

    PlantNET. 2024. The NSW Plant Information Network System. Royal Botanic Gardens and Domain Trust, Sydney. https://plantnet.rbgsyd.nsw.gov.au Accessed July 30, 2024.

    Plants of the World Online (POWO). 2024. Facilitated by the Royal Botanic Gardens, Kew. Published at http://www.plantsoftheworldonline.org/ Accessed July 30, 2024.

    Simmons, M. T. 2005. Bullying the Bullies: The Selective Control of an Exotic, Invasive Annual (Rapistrum rugosum) by Oversowing with a Competitive Native Species (Gaillardia pulchella). Restoration Ecology, 13(4), 609–615. https://doi.org/10.1111/j.1526-100x.2005.00078.x

    Swearingen, J., C. Bargeron. 2016. Invasive Plant Atlas of the United States. University of Georgia Center for Invasive Species and Ecosystem Health. http://www.invasiveplantatlas.org/ .

    Texas Invasives. 2024. Texasinvasives.org. https://texasinvasives.org/plant_database/detail.php?symbol=RARU Accessed April 09, 2024.

    United States Department of Agriculture-Agricultural Research Services (USDA-ARS). 2024. Germplasm Resources Information Network (GRIN), https://npgsweb.ars-grin.gov/gringlobal/taxon/taxonomysearch Accessed October 02, 2024.

    United States Department of Agriculture-Natural Resources Conservation Service (USDA-NRCS). 2024. The PLANTS Database. National Plant Data Team, Greensboro, NC USA. https://plants.usda.gov/home Accessed April 09, 2024.

    Wiersema, John, H. and Blanca León. 2016. World Economic Plants. Available from: VitalSource Bookshelf, (2nd Edition). Taylor & Francis.

    World Flora Online (WFO). 2024. Online. Available at http://www.worldfloraonline.org Accessed April 09, 2024.

     

    Author(s)

    AUTEUR(S)

    Lyrae Willis, Environmental Science Freelance Writer

    Jennifer Neudorf, Canadian Food Inspection Agency, Canada

    Acknowledgement:

    To Taran Meyer of the Canadian Food Inspection Agency for seed imaging.

    contactus@idseed.org

    Last updated
    on 2023-03-27

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