YELLOW-WORT

Blackstonia perfoliata

Gentian Family [Gentianaceae]  

month8jun month8june month8jul month8july month8aug month8sep month8sept month8oct

status
statusZnative
 
flower
flower8yellow
 
morph
morph8actino
 
petals
petalsZ8
(6-8)
type
typeZumbel
 
stem
stem8round
 

2nd July 2009, Southport Sand Dunes, Lancs. Photo: © RWD
A greyish-green annual about 8 inches tall. Centauries are growing around it.


2nd July 2009, Southport Sand Dunes, Lancs. Photo: © RWD
The yellow Gentian-type flowers open only when the sun is out. The leaves are pointed, angled upwards and perfoliate fully enveloping the stem in a cup-shape.


2nd July 2009, Southport Sand Dunes, Lancs. Photo: © RWD
The bracts around each flower are very long and thin.


2nd July 2009, Southport Sand Dunes, Lancs. Photo: © RWD
And usually twisted around at the top on un-opened flowers.


2nd July 2009, Southport Sand Dunes, Lancs. Photo: © RWD
The stem splits into 3 at the junction of a stem leaf; a middle thinner one with shorter-stemmed flower, and two thicker outer ones, which can also split fractally further up.


2nd July 2009, Southport Sand Dunes, Lancs. Photo: © RWD
The flower on the middle shorter stem differs from those on the outer two stems; it is wider.


8th July 2009, Southport Sand Dunes, Lancs. Photo: © RWD
It is sunny! The usually eight-petalled bright-yellow flowers have opened. Sometimes not all petals appear same size.


8th July 2011, Southport dunes, Sefton Coast. Photo: © RWD
The petals un-fold via an 8-bladed spiral turbo-fan arrangement.


8th July 2009, Southport Sand Dunes, Lancs. Photo: © RWD
Un-like some other members of the Gentian Family, the anthers do not get twisted in the un-curling process.


8th July 2009, Southport Sand Dunes, Lancs. Photo: © RWD
Nominally eight stamens, with a deeper-yellow pollen un-usually covering last third of stamen rather than being on an anther at the top as in most other species of flower.


8th July 2009, Southport Sand Dunes, Lancs. Photo: © RWD
When open, the flowers flare like a tuba. The eight sepals are very long and narrow.


2nd July 2009, Southport Sand Dunes, Lancs. Photo: © RWD
The twinned stem leaves are fused into one surrounding the stem. The name for this is 'perfoliate'. Superficially, the leaves of Centauries (such as Common Centaury) look as though they penetrate the leaf in an identical manner, but they do not, Centauries are not perfoliate, although they do look like they are at first glance. Two side-branching stems are ready to grow.


2nd July 2009, Southport Sand Dunes, Lancs. Photo: © RWD
Showing how the two side-branches grow. The leaves have some resemblance to those of Red Valerian.


23rd July 2015, Southport Dune Slacks, Sefton Coast. Photo: © RWD
Lower leaves lack a double-branching stem just above them.


Some similarities to : Gentians and Centauries, to which it is related. Gentians have blue flowers, whereas those of Centauries are pinkish.

Uniquely identifiable characteristics

Distinguishing Feature : The yellow Centaury-like flowers and the glaucous broad pointed leaves attached in opposite pairs to the main stem like a cup surrounding the main stem, in a similar fashion to those of Red Valerian. The plant is half as tall as Red Valerian, but a little taller than most Centauries or Gentians.

The yellow petals usually number 8, but can number anywhere from 6 to 8 inclusive. It is found mainly on sand dunes or on short turf on lime.

It is the only member of the Genus Blackstonia, or at least in the UK.

IRIDOID GLUCOSIDES

Many of these Iridoid Glycosides are present in other members of the Gentian family of plants such as the Centauries and Gentians. The Lonicera Genus and Plantaginaceae families also contain many similar iridoids, secoiridoids and  Secoiridoid Glycosides.

Gentiopicrin (aka Gentiopicroside) has analgesic effects useful for persistent inflammatory pain. It is widely used as a gastric stimulant, specifically for dyspepsia and gastric inflammation, but also for hapatic and gall-bladder disease. Also as an adjunct to chronic inflammatory disease.

Sweroside exhibits significant anti-bacterial properties whilst both Sweroside and Swertiamain exhibit cytotoxicity, but 12 and 3 times less potent (respectively) than is Podophyllotoxin, a well known toxic lignan.


  Blackstonia perfoliata  ⇐ Global Aspect ⇒ Gentianaceae  

Distribution
family8Gentian family8Gentianaceae

 BSBI maps
genus8Blackstonia
Blackstonia

YELLOW-WORT

Blackstonia perfoliata

Gentian Family [Gentianaceae]  

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