SEASIDE CENTAURY

Centaurium littorale

Gentian Family [Gentianaceae]

month8jun month8june month8jul month8july month8aug month8sep month8sept

status
statusZnative
 
flower
flower8pink
 
flower
flower8lilac
 
inner
inner8cream
 
inner
inner8yellow
 
morph
morph8actino
 
petals
petalsZ5
(4)-5
stem
stem8square
 
rarity
rarityZscarce
 

14th July 2014, Ainsdale, Sefton Coast Photo: © RWD
Spreading in a dune-slack.


14th July 2014, Ainsdale, Sefton Coast Photo: © RWD
The White flowers with 5 petals are probably something else; the flowers are about half the size of the pinkish Seaside Centaury.


23rd July 2016, Green Beach, Ainsdale, Sefton Coast Photo: © RWD
A long brownish-green square stem with intervals between long lanceolate to pointed opposite pairs of leaves leads to a top which is branched with a high density of flowers. [The spherical pinkish-fawn flowers are those of Strawberry Clover - of which there are several in the top right corner]


23rd July 2016, Green Beach, Ainsdale, Sefton Coast Photo: © RWD
The square branching stems vary in thickness at every junction. The flowers are held in almost parallel (not divergent) dense small clusters at the ends of each terminal branch.


23rd July 2016, Green Beach, Ainsdale, Sefton Coast Photo: © RWD
Most flowers are on shortish stalks. Stems square with short wings at the corners. The stem-leaf shapes are diagnostic of Seaside Centaury - they are narrow oblong-elliptic with almost parallel sides and obtuse to rounded at the tip (not pointed). Another diagnostic feature is the olive-green colour of stems and leaves - which are that colour perhaps because of infusion of a pinkish dye such as makes the colour of the petals(?).


23rd July 2016, Green Beach, Ainsdale, Sefton Coast Photo: © RWD
The sepals and corolla tube are a darker green, perhaps because of a higher chlorophyll concentration(?).


23rd July 2016, Green Beach, Ainsdale, Sefton Coast Photo: © RWD
The flower petals (corolla lobes) are between 5 and 6.5mm long, making the flower about 9-12mm across.


23rd July 2016, Green Beach, Ainsdale, Sefton Coast Photo: © RWD
On Centarium species there are always 5 filaments with long yellow anthers, which later twist up tightly, plus a single white style bearing 2 lime-green stigmas, which are broadly-rounded to almost flat at the apex.


23rd July 2016, Green Beach, Ainsdale, Sefton Coast Photo: © RWD


23rd July 2016, Green Beach, Ainsdale, Sefton Coast Photo: © RWD
The calyx is usually longer than 3/4 as long as the corolla tube for Seaside Centaury (and usually shorter than 3/4 as long as the corolla tube for the similarly densely-flowered Common Centaury).


23rd July 2016, Green Beach, Ainsdale, Sefton Coast Photo: © RWD
The 5 yellow twisted anthers (the 2 lower ones looking like screws) and 2 lime-green stigmas.


23rd July 2016, Green Beach, Ainsdale, Sefton Coast Photo: © RWD
The various thicknesses of the olive-green stems.


23rd July 2016, Green Beach, Ainsdale, Sefton Coast Photo: © RWD


23rd July 2016, Green Beach, Ainsdale, Sefton Coast Photo: © RWD


Not to be semantically confused with : Seaside Daisy (Erigeron glaucus), Seaside Pansy (Viola tricolor ssp. curtisii) [plants with similar names]

Hybridizes with :

  • (Lesser Centaury) to produce Centaurium × aschersonianum which was found in South Lancs in 2008 - the lengths of the corolla tube and flower stalk are intermediate between the two parents.
  • (Common Centaury) to produce Centaurium × intermedium which is found on dunes on the Sefton Coast, Merioneth and Anglesey but which do not produce offspring readily, except on the Sefton Coast where backcrossing to both parents occurs producing fertile offspring. Other crossings are also possible. These complex products are best left to experts.
Perhaps it is best to look for Seaside Centaury elsewhere where it is not claimed to hybridise and back-cross etc. Luckily your Author was with experts who identified this Seaside Centaury specimen on the Sefton Coast.

Uniquely identifiable characteristics

Distinguishing Feature : For a Centaury, the leaf shape is exclusive to Seaside Centaury: the leaves on the stems are narrow oblong-elliptical and with the sides almost parallel. The apex is round to obtuse.

It is found not only on the Sefton Coast (where it can hybridise) but also on sandy turf and coastal sand dunes from Northern Britain to South Wales and North-east Yorkshire and in County Londonderry.


  Centaurium littorale  ⇐ Global Aspect ⇒ Gentianaceae  

Distribution
 family8Gentian family8Gentianaceae

 BSBI maps
genus8Centaurium
Centaurium
(Centauries)

SEASIDE CENTAURY

Centaurium littorale

Gentian Family [Gentianaceae]