HAIRY BITTER-CRESS

Cardamine hirsuta

Cabbage Family [Brassicaceae]

month8feb month8mar month8march month8apr month8april month8may month8jun month8june month8jul month8july month8aug month8sep month8sept month8oct month8nov

status
statusZnative
flower
flower8white
inner
inner8cream
morph
morph8actino
petals
petalsZ4
stem
stem8round

7th April 2007, Marsden, West Yorkshire. Photo: © RWD
A straggly plant with a basal rosette of pinnate leaves and many stem leaves.


7th April 2007, Marsden, West Yorkshire. Photo: © RWD
Paradoxically, the stems of Hairy Bittercress are usually hairless, but the leaf stalks are hairy. But this specimen bucks the trend anyway!


4th April 2009, Lancaster Canal. Photo: © RWD
Stems mainly straight, with fewer stem leaves than Wavy Bitter-cress.


4th April 2009, Lancaster Canal. Photo: © RWD
Flowers small, less than 4mm across, in a small bunch atop the stem.


4th April 2009, Lancaster Canal. Photo: © RWD
Basal leaves grossly outnumber stem leaves.


4th April 2009, Lancaster Canal. Photo: © RWD
Grows amidst rocks or walls on bare damp soils. Note mosses signifying damp ground.


4th April 2009, Lancaster Canal. Photo: © RWD
The seed pods are curved, narrow and cylindrical, and unlike those of Wavy Bitter-cress frequently over-top the flowers. The stamens number four rather than the six of Wavy Bitter-cress.


4th April 2009, Lancaster Canal. Photo: © RWD
Four white petals.


26th Sept 2008, Greenside, Glenridding, Cumbria. Photo: © RWD
Basal rosette of rounded pinnate leaves.


26th Sept 2008, Greenside, Glenridding, Cumbria. Photo: © RWD
Un-like Wavy Bitter-cress the leaves are sometimes hairy on upper surface.


6th June 2009, Marsden, West Yorks. Photo: © RWD
Stem leaves narrower and pinnate and numbering four or less rather than the five or more of Wavy Bitter-cress.


6th June 2009, Marsden, West Yorks. Photo: © RWD
Ripened seed pods.


28th April 2011, Salford, Lancs. Photo: © RWD
Ripened seed pods, two split open and seeds released. The seeds are arranged similarly to peas in a pod, the slight bulges being visible.


Easily confused with : Wavy Bitter-cress, but, paradoxically, that can have hairy stems whereas Hairy Bitter-cress doesn't (but it does have hairy leaves). Also, the seed-pods of Hairy Bitter-cress usually over-top the flowers, whereas those in Wavy Bitter-cress are usually lower than the top-most flower. Wavy Bitter-cress has nominally six stamens whereas Hairy Bitter-cress has but four. The number of stem leaves also differs: Wavy Bitter-cress has between four and ten whereas Hairy Bitter-cress has only one to four stem leaves. Although the leaves of Wavy Bitter-cress are hairless, those of Hairy Bitter-cress only might possibly be hairy.

Not to be confused with : Hairy Rock-cress, Hairy Greenweed, Hairy Bindweed, Hairy Stonecrop, Hairy Violet, Hairy St John's Wort, Hairy-fruited Broom, Hairy Mock-Orange, Hairy Garlic or Hairy Tare, etc [plants with similar names].

Hybridizes with : Wavy Bitter-cress (Cardamine flexuosa) to produce Cardamine × zahlbruckneriana (Cardamine flexuosa × hirsuta) but luckily this is present in but very few locations, and is not present where the above photographs were taken.

Some similarities to : Hairy Rock-cress

Flowers over a longer time period than that of Wavy Bitter-cress, from February to November, and all year in mild winters.

Habitat: bare ground, usually damp, including dunes, or rocks, walls and especially garden beds. Ubiquitous almost, but not quite, throughout the UK.

But beware about using the number of stamens as the sole identifier. Hairy Bitter-cress is most likely to have only 4 stamens, but it can have 5 or 6! Likewise, Wavy Bitter-cress is most likely to have 6 stamens (2 deeper down in the flower than the rest) but it can have only 5 or only 4! Use as many other differing characteristics as possible for ID.


  Cardamine hirsuta  ⇐ Global Aspect ⇒ Brassicaceae  

Distribution
 family8Cabbage family8Brassicaceae

 BSBI maps
genus8Cardamine
Cardamine
(Bitter-cresses)

HAIRY BITTER-CRESS

Cardamine hirsuta

Cabbage Family [Brassicaceae]

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