• Sutro Stewards

Nature on my Daily Walks

Updated: Dec 11, 2020

Hirschfeldia incana (formerly Brassica geniculata) is a species of flowering plant in the mustard family.

Background Information

It is a perennial herb which is not native to California. It was first collected in North America in 1895 in the San Bernardino region of California and by 1936 it was described as a serious agricultural pest (Flora of North America Editorial Committee, 1993).


Synonyms: Brassica geniculata, Sinapsis geniculata, Sinapsis incana.


It is well known with it's common Names: short-pod mustard; Mediterranean mustard; summer mustard; Greek mustard, as well as buchanweed, hoary mustard.


The species is native to the Mediterranean Basin but it can be found in many parts of the world as an introduced species and often a very abundant noxious weed. This mustard is very similar in appearance to black mustard, but is generally shorter. It forms a wide basal rosette of lobed leaves which lie flat on the ground, and it keeps its leaves while flowering. Its stem and foliage have soft white hairs.

Plants of H. incana often grow alone, rather than in the dense colonies that seem to be the rule for the other mustards.


Native to West and Central Asia, parts of Europe, and North Africa, and it has become naturalized in Oceania and temperate zones of Eurasia. It is found in habitat openings caused by natural disturbances, such as roadsides and pastures. It has been reported to accumulate heavy metals and possibly interfere with fire regimes. Seeds are produced in large numbers and are likely to survive in the soil for several years. A weed of economic importance, it infests small grain crops and spreads as a contaminant of fodder, and sometimes seed.

Human role

Due to its potential as a seed contaminant, H. incana is reported to be considered amongst the world’s most economically important weeds (Wiersema and León, 1999). This species is one of the crucifer weeds that competes with broadacre crops and pasture (South East Natural Resources Management Board, 2009).


In Argentina, this species has been reported as an agricultural weed of secondary importance in small grain crops such as canola (oilseed rape) and alfalfa (Marzocca, 1976) and also infests wheat and barley (Heap, 2015).


The young plant is gathered in spring and boiled in water and eaten with oil and lemon juice in parts of Mediterranean (Facciola, 1990; Siemens, 2011). According to Moerman (1998), seeds can be ground into powder then mixed with water and eaten. According to Siemens (2011), in the times of Dioscorides H. incana was used as a pot plant. H. incana has also been used as a vegetable in Italy, specifically the whorls and shoots of the plant (Biscotti & Pieroni, 2015).

Impact on Habitats

According to Brooks (2004), H. incana possibly interferes with fire regimes by increasing fuel loads. However interference only occurs where alien annual grasses have already altered the fire regime, thus the additional effect of this species may be marginal. Moreover, this species may reduce fecundity of co-existing species. Due to its maturation early in the phenologic year, it possibly usurps soil water before other native annual plants reach peak development (Brooks, 2004).

Environmental Services

H. incana could be potentially employed in phytoremediation projects of soils contaminated with industrial residues (Siemens, 2011). Moreover, it could be considered as a good experimental model to identify genes involved in the tolerance and accumulation of heavy metals in plants.

Resources

https://www.calflora.org/cgi-bin/species_query.cgi?where-calrecnum=4196

https://www.cal-ipc.org/plants/paf/hirschfeldia-incana-plant-assessment-form/

https://www.cabi.org/isc/datasheet/114820#tohistoryOfIntroductionAndSpread

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