{{Short description|Genus of flowering plants}}{{Inline|date=September 2024}}{{Automatic taxobox | image = Bolletjesraket 19-05-2006 12.28.38.JPG | image_caption = ''Rapistrum rugosum'' | taxon = Rapistrum | authority = Crantz | subdivision_ranks = Species | subdivision = *''Rapistrum perenne'' {{small|(L.) All}} *''Rapistrum rugosum'' {{small|(L.) All}} | subdivision_ref = <ref name = powo>{{cite web |title=''Rapistrum'' Crantz |url=https://powo.science.kew.org/taxon/urn:lsid:ipni.org:names:331896-2 |website=Plants of the World Online |publisher=Royal Botanic Gardens, Kew |access-date=2 October 2025}}</ref> | synonyms = *''Arthrolobus'' {{small|Andrz. ex DC.}} *''Schrankia'' {{small|Medik.}} | synonyms_ref = <ref name = powo/> }}
'''''Rapistrum''''', the '''bastard cabbages''',<ref>{{PLANTS|id=RAPIS|taxon=Rapistrum|access-date=18 October 2015}}</ref>{{Better citation needed|reason=The current source is insufficiently reliable (WP:NOTRS).|date=September 2024}} is a genus of the family Brassicaceae with a distinctive cross like arrangement of its petals. It is also known<ref>{{Cite web |title=Rapistrum |url=http://beta.floranorthamerica.org/Rapistrum |access-date=2024-09-12 |website=Flora North America}}</ref> as '''wild-turnip''' or '''turnipweed'''. Species of ''Rapistrum'' are annual to perennials (Lifespan from 1 to 2 or more years). The yellow petals are accompanied by sepals that stand vertically at near right angles (erecto-patent). Leaf shape and arrangement varies from rough toothed (dentate) to a configuration of opposingly lobed pairs along the plant stalk, pinnately lobed.
== Etymology == The word "Rapistrum" is formed from the Latin ''rapa'' ("turnip") and ''-astrum'', ("incomplete resemblance").<ref>{{Cite web |last=Warwick |first=Suzanne I. |title=Rapistrum |url=http://beta.floranorthamerica.org/Rapistrum |website=Flora North America}}</ref>
==Fruit== The genus ''Rapistrum'' has a characteristic fruit comprising two segments, one distal and one proximal:
* The distal (upper division) is the part of the fruit farthest away from the point of attachment. The distal is endowed with a ribbed spheroid base (globose) that tapers to form a narrowed projection. It holds a single seed.
* The proximal (lower division) is the part of the fruit nearest to the point of attachment. Possesses a more uniform narrower shape compared to the distal above, giving the fruit a waist. It holds a maximum of three seeds, more commonly none or one.
The fruit varies between species in the genus. The distal of ''R. rugosum'' is strongly ribbed and narrows to form a beak whereas ''R. perenne'' is comparatively less wrinkled and ends with a style that stubbornly resists detachment, 'a persistent style'.
When ripe the distal breaks away in an across-wise fashion, breaking transversely.
==References== {{Commons category|Rapistrum}} {{Reflist}}
== Bibliography == *{{Citation | surname=Stace | given=C. | author-link = Clive Stace |title=Field flora of the British Isles| publisher=Cambridge University Press | place=Cambridge | year=1999 |ISBN=0-521-65315-0}}. *{{Citation | surname=Streeter | given=D. | title=The wild flowers of the British Isles| publisher=Midsummer Books Ltd. | place=London | year=1983 |ISBN=1-900732-03-3}}.
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Category:Brassicaceae genera Category:Plants described in 1769