SHEPHERD'S CRESS

Teesdalia nudicaulis

Cabbage Family [Brassicaceae]

month8apr month8april month8may month8jun month8june month8jul month8july month8aug month8sep month8sept month8oct

status
statusZnative
flower
flower8white
inner
inner8yellow
morph
morph8zygo
petals
petalsZ4
type
typeZspiked
stem
stem8round
rarity
rarityZuncommon

28th April 2016, a slate quarry, Leicestershire. Photo: © Richard Mabbutt
Grows uo to 25cm high on either open sand, gravel or shingle, here amidst broken slate.


28th April 2016, a slate quarry, Leicestershire. Photo: © Richard Mabbutt


28th April 2016, a slate quarry, Leicestershire. Photo: © Richard Mabbutt
With a basal rosette of leaves.


28th April 2016, a slate quarry, Leicestershire. Photo: © Richard Mabbutt
From above the fruits spread out from the stem in a circle.


Photo: © Dawn Nelson
A hairless low to short annual plant, here amidst mosses. It avoids lime.


Photo: © Dawn Nelson
As-yet unopened flower buds


Photo: © Dawn Nelson
Flower buds with 4 sepals which can turn purplish, as can other green parts of the plant.


5th May 2016, Murlough NNR, Northern Ireland. Photo: © Lesley Crawshaw
The fruits are flattened and heart-shaped - they consist of two wings either side of the style, forming an overall more-rounded shape than the otherwise fairly similar fruits of Shepherd's Purse. The pedestal upon which the fruit is based is also very pronounced whereas the pedestal for the fruit is a lot smaller in relation to the fruit for Shepherd's Purse. Also the stalk of the fruit is much shorter and stubbier in proportion to the stalks of the fruits on Shepherd's Purse


Photo: © Dawn Nelson
There are 4 petals, but an identifying feature is that 2 adjacent petals are much longer than the other 2. Stamens number 6, bearing cream-coloured anthers/pollen. Some fruits are growing larger still within the petals. The style right in the nook of the fruit is tiny and yellowish-cream.


5th May 2016, Murlough NNR, Northern Ireland. Photo: © Lesley Crawshaw
Four cupped sepals hold the flower with all petals longer than the sepals, with a pair being twice as long as the other pair reminiscent of Candytufts such as Perennial Candytuft, another member of the same family, Brassicaceae. In the centre a flattened brown seed pod develops with the tiny discoidal cream-coloured style still in place. The seed pod is surrounded by 6 stamens with cream-colured pollen in an oval configuration: an opposite pair of stamens at the edge of the seed pod, and a pair of stamens each side of the seed pod.


5th May 2016, Murlough NNR, Northern Ireland. Photo: © Lesley Crawshaw
Rarely upright or straight, the plant flowers first at the bottom of the inflorescence which therefore ripen first into fruits which space themselves out further as the stem still extends. Fruit ≤ thrice as long as wide.


5th May 2016, Murlough NNR, Northern Ireland. Photo: © Lesley Crawshaw
Although the pods are flattened, they are not planar, but instead usually cupped into a upwardly-directed spoon-shape reflecting the original asymmetry of the 2 + 2 petals, where one set of 2 is much longer (about twice as long) than the other set of petals.


Photo: © Dawn Nelson
Basal leaves are highly variable in shape and size, these more so than others. The basal leaves are described as pinnate in the books, but these particular ones have failed to develop more than 2 side-lobes.


Photo: © Dawn Nelson
The leaves are a matt-green with a long and grooved rachis. Plant is shortly-hairy as here.


28th April 2016, a slate quarry, Leicestershire. Photo: © Richard Mabbutt
Stem leaves are few only, most are basal leaves, described as pinnate in the books but here there are but few with more than one pair of side-lobes (bottom right).


This is not related to any Dahlias found in the Teeside.

Not to be semantically confused with : Shepherd's Purse (Capsella bursa-pastotis) nor with Red Shepherd's Purse (Capsella rubella) [plants with similar names in the same family]. Nor with Shepherd's Needle (Scandix pecten-veneris) [an umbellifer]

Hybridises with : Flower ()

Some similarities to plants with similar-shaped fruits, such as: Shepherd's Purse (Capsella bursa-pastoris) [but that is much taller, has auriculate stem leaves and lobed basal leaves], Field Penny-Cress (Thlaspi arvense) [but that is also taller with auriculate and slightly-lobed stem leaves and has more-circular fruits with an oval centre bulge], Alpine Penny-cress (Noccaea caerulescens) [but that has simple lanceolate basal leaves, and arrow-head-shaped auriculate stem leaves], perfoliate Penny-cress (Microthlaspi perfoliatum) [but that also has slightly-lobed basal leaves and similarly-shaped auriculate stem-leaves and with a central bulge in the fruit which occupies a larger (in proportion to the rest of the fruit) area]

It is a un-common native plant [R] scattered locally throughout much of the UK but present in Ireland only in the North East. Growing in open sand, gravel or shingle. A major ID feature is the comparitive length of the 4 petals, with a pair about twice as long as the other pair, it is thus zygomorphic.


  Teesdalia nudicaulis  ⇐ Global Aspect ⇒ Brassicaceae  

Distribution
 family8Cabbage family8Brassicaceae

 BSBI maps
genus8Teesdalia
Teesdalia
(Shepherd's Cress)

SHEPHERD'S CRESS

Teesdalia nudicaulis

Cabbage Family [Brassicaceae]