Brassica nigra

Traceable determination

Record the authority, evidence and uncertainty behind the identification without creating separate things for nomenclatural alternatives.

1. Which taxonomic reference and version define the Brassica nigra concept used for this determination? definition
2. Which voucher, photographs or parent-plant record connect this physical subject to that determination? provenance

Diagnostic character combination

Assess multiple characters together and preserve uncertainty when mature fruits are unavailable.

1. What are the mature fruit orientation, valve-body length, beak length, surface hairs and cross-section? measurement
2. Which observed characters exclude Brassica juncea, Brassica rapa, Sinapis alba and other locally plausible lookalikes? boundary
3. If only seedlings or loose seeds are available, what additional evidence is needed before assigning this species? action

Stage and timing

Record dated stages rather than importing a flowering calendar from another region.

1. Which vegetative, flowering and fruiting stages coexist on this plant or within the sampled stand? measurement
2. Which dated observations establish emergence, first flowering and first mature fruit at this location? provenance

Condition without assumed cause

Describe symptoms by organ and retain a separate confidence assessment for their cause.

1. What proportion of leaves, stems and reproductive structures shows damage, wilting or premature death? measurement
2. What evidence distinguishes normal senescence from water stress, herbivory, disease or treatment injury? boundary

Seed release readiness

Use direct fruit and seed observations to judge collection timing and handling needs.

1. What fraction of sampled siliques contains developed seeds, and what fraction is open or has shed seeds? measurement
2. How should collection or removal be timed and handled given the observed seed-release condition? action

Viability and emergence evidence

Keep germination results, viability assessments and inferred dormancy distinct.

1. What germination or viability result was obtained under which conditions, using how many seeds? measurement
2. What evidence distinguishes nonviable seeds from viable seeds that did not germinate under the test conditions? boundary
3. What field observations link new seedlings to this occurrence rather than a separate seed introduction? provenance

Establishment context

Distinguish documented sowing from spontaneous occurrence and unresolved origin.

1. Was this occurrence deliberately sown, linked to escaped cultivation, associated with introduced material or of unknown origin? provenance
2. Which local authority or flora supports any assigned native, introduced, naturalised or regulated status? provenance

Spread evidence

Separate measured change from assumptions that every black mustard occurrence is invasive.

1. How have occupied area, plant density and reproductive plant counts changed under comparable surveys? measurement
2. What evidence shows recruitment beyond the planted or previously observed boundary? boundary

Material destination

Preserve plant identity and handling provenance when material becomes a voucher, seed lot or harvested ingredient.

1. Which organs are being collected, at what developmental stage, and for which intended destination? action
2. Which downstream model must assess food, feed, extraction or medicinal suitability before that use is authorised? boundary

Stage-dependent action

Record the objective, applicable constraints and evidence that an intervention achieved its intended result.

1. Given identity confidence, fruit maturity and site objectives, should this occurrence be retained, monitored, collected or removed? action
2. What handling and locally applicable constraints govern moving plants, seeds or associated soil? boundary
3. What follow-up observations will detect surviving plants, later seed maturation or new recruitment? measurement

Kinds and varieties

Reported by the breadth pass; each item needs checking against its source before it becomes normative.

• Cultivated spice landraces grown for seed
• Whole black-mustard seed as a spice-trade commodity
• Ground or prepared black-mustard condiment
• Feral roadside and cereal-field weeds
• Invasive wildland annual stands (especially California and other Mediterranean-climate grasslands)
• BB-genome germplasm and breeding accessions
• High-erucic seed oil (limited edible or industrial use)
• Historical Dijon-type condiment mustard (now largely replaced in trade by Brassica juncea)

1. Which of these kinds and varieties hold for the sense of Brassica nigra this model covers, and on what evidence? provenance

Identifiers and schemes

Reported by the breadth pass; each item needs checking against its source before it becomes normative.

• Scientific name - Brassica nigra (L.) W.D.J.Koch - Basionym Sinapis nigra L.; family Brassicaceae.
• NCBI Taxonomy - 3707 - Standard taxid in sequence and genome records.
• USDA PLANTS symbol - BRNI - Identifier for the United States and territories.
• EPPO code - BRSNI - Plant-protection code for Brassica nigra.
• ITIS TSN - 23062 - Taxonomic Serial Number in the Integrated Taxonomic Information System.
• Harmonized System (HS) - 1207.50 - Mustard seeds as a commodity heading; not species-specific (also covers Sinapis alba and Brassica juncea).

1. Which of these identifiers and schemes hold for the sense of Brassica nigra this model covers, and on what evidence? provenance

Standards and regulation

Reported by the breadth pass; each item needs checking against its source before it becomes normative.

• Regulation (EU) No 1169/2011, Annex II - mustard is a mandatory labelled food allergen (European Parliament and Council).
• Canadian priority-allergen rules - mustard must be declared on food labels (Health Canada / Canadian Food Inspection Agency).
• Regulation (EU) 2019/1870 amending contaminants rules - maximum erucic acid in vegetable oils, with a distinct limit for mustard oil used as food (European Commission).
• ISTA International Rules for Seed Testing - purity, other-seed, and germination methods applied to Brassica seed lots (International Seed Testing Association).
• OECD Seed Schemes for Brassica and Sinapis - varietal certification of mustard seed moving in international trade (OECD).

1. Which of these standards and regulation hold for the sense of Brassica nigra this model covers, and on what evidence? provenance

Real-world use

Reported by the breadth pass; each item needs checking against its source before it becomes normative.

• Whole seeds used in pickling spice, sausage, and hot-oil tempering (tadka) for pungency.
• Ground or steeped to make hot mustard condiments; historically the seed of Dijon mustard, now mostly replaced in factories by Brassica juncea because nigra siliques shatter.
• Pressed for a high-erucic mustard oil in some traditional and industrial uses, far less often than B. juncea.
• Traditional mustard plasters (counter-irritant poultices) using crushed seed.
• Cover crop or green manure, and a volunteer weed of cereals and roadsides.
• Invasive annual forming dense stands on California coastal sage, grassland, and disturbed ground.
• BB-genome parent in Brassica genetics, resynthesis, and breeding (U's triangle).

1. Which of these real-world use hold for the sense of Brassica nigra this model covers, and on what evidence? provenance

Typical measurements

Reported by the breadth pass; each item needs checking against its source before it becomes normative.

• Chromosome number (BB genome) - 2n = 16 (n = 8) - chromosomes
• Plant height at flowering - 0.5-2.5 - m
• Seed diameter - 1.0-1.5 - mm
• Thousand-seed mass - 1.5-3 - g
• Seed oil content - 25-40 - % of dry seed mass
• Erucic acid in seed oil - about 25-45 - % of fatty acids

1. Which of these typical measurements hold for the sense of Brassica nigra this model covers, and on what evidence? provenance

Failure modes and hazards

Reported by the breadth pass; each item needs checking against its source before it becomes normative.

• Siliques dehisce at ripeness, so combine harvest sheds much of the seed - the main agronomic reason commerce shifted to Brassica juncea.
• Invasive annual stands can displace native forbs and raise dry fuel load in Mediterranean-climate grasslands.
• IgE-mediated mustard allergy, a priority allergen in the EU and Canada and a cause of undeclared-ingredient recalls.
• Allyl isothiocyanate vesicates skin and irritates mucosa (mustard plasters; handling of freshly crushed seed).
• High-erucic seed oil is restricted as an edible oil in several jurisdictions because of historical cardiac-lipidosis concerns.
• Glucosinolate-rich forage can be goitrogenic to livestock when mustard dominates the sward.
• Volunteer weed in small-grain crops and a contaminant of other mustard-seed lots.

1. Which of these failure modes and hazards hold for the sense of Brassica nigra this model covers, and on what evidence? provenance

Regional variation

Reported by the breadth pass; each item needs checking against its source before it becomes normative.

• In grocery and export trade, lots labelled "black mustard seed" are often Brassica juncea, not B. nigra.
• France: historically tied to Dijon mustard; commercial Dijon is now typically B. juncea.
• California and much of the western United States: encountered mainly as an invasive wild plant, not as a crop.
• Canadian Prairie mustard production is Sinapis alba (yellow) and Brassica juncea (brown/Oriental), with little or no B. nigra.
• Ethiopia and parts of the eastern Mediterranean retain more true B. nigra as a spice; Ethiopian mustard as an oilseed/vegetable is the separate species B. carinata.
• English trade names black / brown / yellow mustard do not map cleanly onto species.

1. Which of these regional variation hold for the sense of Brassica nigra this model covers, and on what evidence? provenance

Neighbouring kinds and how to tell them apart

Reported by the breadth pass; each item needs checking against its source before it becomes normative.

• Brassica juncea (brown/Indian/Oriental mustard) - Juncea seeds are larger and usually brown rather than jet-black; siliques spread from the rachis rather than lying appressed; 2n = 36 (AABB) versus 2n = 16 (BB).
• Sinapis alba (white/yellow mustard) - Seeds are pale yellow and larger; the main glucosinolate is sinalbin, not sinigrin; siliques are bristly with a long flattened beak.
• Brassica rapa (field mustard / turnip rape) - Upper cauline leaves of B. rapa clasp the stem with auricles; B. nigra upper leaves are petiolate and do not clasp; 2n = 20 (AA).
• Hirschfeldia incana (shortpod mustard) - Short, hairy siliques with a persistent swollen beak; a frequent California roadside misidentification of "black mustard."
• Brassica tournefortii (Saharan mustard) - Different basal-rosette phenology and fruit; another invasive mustard of the south-western United States, not the classical spice seed.
• Brassica carinata (Ethiopian mustard) - Tetraploid BBCC crop (2n = 34) with larger plants and seeds; an oilseed/vegetable, not small-seeded black mustard spice.
• Sinapis arvensis (charlock / wild mustard) - Spreading bristly siliques and different leaf division; seeds are not the commercial black-mustard spice.

1. Which of these neighbouring kinds and how to tell them apart hold for the sense of Brassica nigra this model covers, and on what evidence? provenance