SEA MOUSE-EAR

Cerastium diffusum

Carnation & Campion (Pink) Family [Caryophyllaceae]

month8apr month8april month8may month8jun month8june month8jul month8july

status
statusZnative
 
flower
flower8white
 
inner
inner8cream
 
morph
morph8actino
 
petals
petalsZ4
4-(5)
petals
petalsZcleft petalsZcut
 
stem
stem8round
 



19th April 2018, brick shorline, Hightown, sefton Coast. Photo: © RWD


19th April 2018, brick shorline, Hightown, sefton Coast. Photo: © RWD


19th April 2018, brick shorline, Hightown, sefton Coast. Photo: © RWD
Sheltered by a liverpool brick these specimens have been bold enough to grow a little taller than the rest in order that you see them more clearly. In this one small 20m round area your Author counted over 20 differing species all vying for this prime brick-splattered spot on the shore, not far from the danger of the sea.


19th April 2018, brick shorline, Hightown, sefton Coast. Photo: © RWD


19th April 2018, brick shorline, Hightown, sefton Coast. Photo: © RWD
Two short specimens out in the open, where they are more vulnerable to the waves at high tides. Two unopened buds with reddish tips just below them. Among the round leaves of other plants.


19th April 2018, brick shorline, Hightown, sefton Coast. Photo: © RWD
Unopened flower buds on the right and at bottom.


19th April 2018, brick shorline, Hightown, sefton Coast. Photo: © RWD
As-yet unopened flowers are at the bottom, amongst the round leaves of something else.


19th April 2018, brick shorline, Hightown, sefton Coast. Photo: © RWD


19th April 2018, brick shorline, Hightown, sefton Coast. Photo: © RWD


22nd May 2017, Loggerheads Country Pk, North Wales. Photo: © RWD
A low-growing (up to 8cm - occasionally 30cm) decumbent to erect annual which usually grows near the sea, but these specimens were high up a hill well inland in North Wales. (Ignore the whorls of pointed-tipped leaves - those belong to a Bedstraw)


22nd May 2017, Loggerheads Country Pk, North Wales. Photo: © RWD
Unusually for Mouse-ears which usually have 5 petals, Sea-mouse Ear usually has but 4 petals, 4 sepals, and 4 styles. The petals are deeply cleft. The petals are said to be 3/4 ths the length of the sepals, but all photos your Author has found on the internet have the petals about stretching to about the same radius as the sepals (perhaps we are supposed to measure their lengths independently, rather than comparatively in-situ?). If the flowers have 5 petals, then they will also (usually) have 5 sepals and 5 styles. The numbers of stamens they have varies from 4 to 5, but, it seems, not necessarily mirroring the number of petals. For instance, this specimen has 4 petals but 5 stamens, whilst the ones in the set above this one have 4 of each (one has obviously dropped off on the 1st).


19th April 2018, brick shorline, Hightown, sefton Coast. Photo: © RWD
This specimen has narrow white margins on the sepals whilst others seem not to.


22nd May 2017, Loggerheads Country Pk, North Wales. Photo: © RWD
The sepals have both glandular sticky hairs and normal hairs. The green parts of the sepals are uniformly green. They also have no white margins. Cream-coloured anthers and a stigma splitting near the end into 4 white styles.


Not to be semantically confused with : Mouse-ear-hawkweed (Pilosella officinarum), Mousetail Plant (Arisarum proboscideum), Mousetail (Myosurus minimus) or Starwort Mouse-ear (Cerastium cerastoides) [plants with similar names belonging to differing families].

Easily mis-identified as : other Mouse-ears and to a lesser extent Stitchworts (which all have white flowers with cleft petals, but in the case of Stitchworts the clefts are very deep). However, all those nominally have flowers with five petals whereas Sea Mouse-ear usually has only four petals (only occasionally 5). Uniquely identifiable characteristics

Distinguishing Feature : A Mouse-ear with only 4 white (cleft) petals.

It is a native annual plant which occurs most often by or near the sea on sand, shingle, or open shortish grassland. It is occasionally found further inland, as in these photos, or alongside salted roads and used to be found in amongst railway ballast. As is to be expected growing near the sea it is a Halophyte, tolerating a salty diet. But it doesn't grow in the tidal zone where it would get washed away twice a day... The leaves are 5-18mm long and often with a purple rim like the tips of the sepals, which are supposed to be fringed white (they are in some of the photos from Loggerheads Country Park, but not in others). According to the books the hairs on the sepals never extend beyond the tips of the sepals, but it is well known that plants cannot read and often blatantly break the rules, as do the specimens from the Loggerheads Country Park above. The flowers are small, only 3-6mm across.

The bracts are uniformly green. The plant is only rarely hairless, preferring to have many glandular hairs and some non-glandular hairs over the plant (except, of course, the petals and sex organs).

The fruit capsule is 5 to 7.5mm long, straight and usually has 8 teeth (up to 10).


  Cerastium diffusum  ⇐ Global Aspect ⇒ Caryophyllaceae  

Distribution
 family8Carnation & Campion (Pink) family8Caryophyllaceae

 BSBI maps
genus8Cerastium
Cerastium
(Mouse-Ears)

SEA MOUSE-EAR

Cerastium diffusum

Carnation & Campion (Pink) Family [Caryophyllaceae]