CREEPING YELLOW-CRESS

Rorippa sylvestris

Cabbage Family [Brassicaceae]

month8jun month8june month8jul month8july month8aug month8sep month8sept

status
statusZnative
flower
flower8yellow
morph
morph8actino
petals
petalsZ4
stem
stem8angular
sex
sexZbisexual

4th Aug 2009, arable fields, Rufford, Lancs. Photo: © RWD
Meanwhile, later in the year, elsewhere:
Growing in an arable field, up to 60cm high. Spreads by white rhizomes which root along the way.


4th Aug 2009, arable fields, Rufford, Lancs. Photo: © RWD
Deep yellow flowers.


4th Aug 2009, arable fields, Rufford, Lancs. Photo: © RWD
Flowers crowded.


4th Aug 2009, arable fields, Rufford, Lancs. Photo: © RWD
Pods usually curved with a long stalk, when mature they should grow longer than their stalks.


4th Aug 2009, arable fields, Rufford, Lancs. Photo: © RWD
Four oblong sepals pigmented green to yellow. Stems ribbed.


4th Aug 2009, arable fields, Rufford, Lancs. Photo: © RWD
Sepals oblong and green to yellow (right bottom). Six yellow stamens with orange-yellow anthers. Petals rounded at apex.


4th Aug 2009, arable fields, Rufford, Lancs. Photo: © RWD
Upper stem leaves have 1-3 lateral lobes, leaves rarely simple. Stems angled.


4th Aug 2009, arable fields, Rufford, Lancs. Photo: © RWD
Stigma yellow, capitate and emarginate.


4th Aug 2009, arable fields, Rufford, Lancs. Photo: © RWD
Pods must have some growing still to do, they should be longer than their stalks,


4th Aug 2009, arable fields, Rufford, Lancs. Photo: © RWD
The basal rosette leaves do not persist, and presumed absent here. Leaves highly variable. Lower stem leaves up to 15cm long, between pinnate to pinnatisect, with a terminal lobe of various shapes, and between 3 and 6 pairs of lateral lobes (which are variously lanceolate to linear. The margins are either un-toothed (entire) or deeply toothed.


16th April 2008, Photo: © RWD


Casually mistaken for : Creeping Buttercups (Ranunculus repens) but they have five petals.

Hybridizes with :

  • Great Yellow-Cress (Rorippa amphibia) to produce Hybrid Yellow-cress (Rorippa × anceps) The most body of the hybrids, being found in just about 20 hectads. Unlike Creeping Yellow-cress it has fewer lobes on the upper leaves and which areacutely-lobed. This hybrid is fertile and variable to it back-crossing with either of its parents.
  • Austrian Yellow-cress (Rorippa austriaca) to produce Rorippa × amoracioides which has only ever been spotted in only 10 hectads in the last 15 years (as of 2015). Unlike Creeping Yellow-cress it has fewer lobes on the leaves and which are acutely lobed.
  • Marsh Yellow-Cress (Rorippa paluatris) to produce an un-named hybrid that is not in the books, but which appears on the BSBI map data.
There are other small differences too between these hybrids.

No relation to : Yellow-wort (Blackstonia perfoliata) [a plant with similar name belonging to the Gentianaceae (Gentian family)].

A native of riverbanks, water-courses, lakes, margins of ponds, damp bare ground and even brackish swamps. Becomes a noxious weed on arable land, docksides, waste ground and gardens. It is highly variable in leaf shape, fruit shape and form or jizz.


  Rorippa sylvestris  ⇐ Global Aspect ⇒ Brassicaceae  

Distribution
 family8Cabbage family8Brassicaceae
 BSBI maps
genus8Rorippa
Rorippa
(Yellow-Cresses)

CREEPING YELLOW-CRESS

Rorippa sylvestris

Cabbage Family [Brassicaceae]

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