SafePlants

White Ball-mustard (Calepina irregularis)

White Ball-mustard, scientifically known as Calepina irregularis, is an annual or perennial herb characterized by its distinctive white flowers and ball-like fruits. It is also known by the German name, Kalepine.

Considerations for Pets

• This plant has a weak stem and small, ball-like fruit, which may present a choking hazard for pets if ingested.

Considerations for Children

• The plant produces small, ball-like fruits on stalks, which could be attractive to young children and may pose a choking hazard if swallowed.

Taxonomy and Nomenclature

• Scientific Name: Calepina irregularis (Asso) Thell.
• Family: Brassicaceae (Implied, given relation to mustard and mustards are in Brassicaceae)
• Taxon Version Key: NBNSYS0200001224

Distribution and Habitat

• Native to Europe.
• Found in countries including France (FR), Italy (IT), Bulgaria (BG), and the United States (US).
• Specific locations include the Parco fluviale del Po e dell'Orba in Italy, the Piemonte region of Italy, and the Mediterranean Region.
• In the US, it has been found in Virginia and North Carolina.
• Commonly found along roadsides and trackside on limestone mountains.
• Introduced to Britain.
• Considered a new weed in Australia.

Morphological Characteristics and Growth Habits

• It is a weak-stemmed herb with lobed leaves, growing as a rosette.
• The plant has 4-petaled white flowers.
• It produces small, ball-like fruits on stalks along the flowering stem.
• The leaves are grey-green and arrow-shaped.
• It is an annual or biennial herb.

Quirky Facts

• In the 15th and 16th centuries, "mustard balls" were a popular form of prepared mustard.

Further Information

• Botanical Society of British Isles: http://www.bsbi.org.uk/
• Botany Department, The Natural History Museum