PERFORATE ST JOHN'S-WORT

Hypericum perforatum

St John's-wort Family [Hypericaceae]

month8jul month8july month8aug month8sep month8sept

status
statusZnative
 
flower
flower8yellow
 
inner
inner8orange
 
morph
morph8actino
 
petals
petalsZ5
 
stem
stem8round
 
stem
stem8winged
(2)
toxicity
toxicityZlowish
 
sex
sexZbisexual
 

27th July 2008, Bouldnor, IoW. Photo: (CC by 2.0) Hilary Higgins
According to Clive Stace it is supposed to have round stems with just 2 short wings each side and growing to 80cm high, but this specimen has square stems. It is an erect and hairless perennial with a rhizome root system


5th July 2014, Rimrose Valley Country Pk, Sefton, Merseyside. Photo: © RWD
From the top down.


5th July 2014, Rimrose Valley Country Pk, Sefton, Merseyside. Photo: © RWD
The petals (and sepals) are mostly devoid of black glands.


27th July 2008, Bouldnor, IoW. Photo: (CC by 2.0) Hilary Higgins
Going to fruit at the top of the inflorescence.


2nd July 2008, quarry, Tapnell, IoW. Photo: (CC by 2.0) Geoff Toone


2nd July 2008, quarry, Tapnell, IoW. Photo: (CC by 2.0) Geoff Toone
This specimen might be the most convincing specimen of Perforate St John's-wort here with both round stems (with two slight ribs) and no black dots on the petals and sepals.


Photo: © RWD
Whereas this specimen has black streaks on the petals.


29th July 2008, Westover Plantation, IoW. Photo: (CC by 2.0) Hilary Higgins
Black dots on the edges of leaves.


Photo: © RWD
The translucent dots are best seen against the light.


27th July 2008, Bouldnor, IoW. Photo: (CC by 2.0) Hilary Higgins
This specimen also anomalously has square stems.


Photo: © RWD
With no black dots on either sepals or petals this might be another good example of Perforate St John's-wort.


Photo: © RWD
The sepals also conform with Perforate St John's-wort with those being about equal in length, entire (without teeth) and tapering to a point.


Photo: © RWD
And it also has the requisite black dots and translucent marks on the leaves plus the stems are round (err, ish)...


Photo: © RWD
The leaves on the main stem are usually widest near their base and stalkless and nearly clasping the stem.


16th Feb 2007, Mottistone, IoW. Photo: (CC by 2.0) Mike Cotterill
The fruit are a striking brilliant red.


16th Feb 2007, Mottistone, IoW. Photo: (CC by 2.0) Mike Cotterill
The fruit.


16th Feb 2007, Mottistone, IoW. Photo: (CC by 2.0) Mike Cotterill
The scarlet-red fruit.




A Hybrid (?) with Imperforate St John's-Wort

Des Etangs' St John's-wort

Hypericum × desetangsii

23rd Aug 2015, dirt track, nr. Warrington, Cheshire. Photo: © RWD
They are certainly tall comensurate with it being a hybrid.


23rd Aug 2015, dirt track, nr. Warrington, Cheshire. Photo: © RWD


23rd Aug 2015, dirt track, nr. Warrington, Cheshire. Photo: © RWD


23rd Aug 2015, dirt track, nr. Warrington, Cheshire. Photo: © RWD


23rd Aug 2015, dirt track, nr. Warrington, Cheshire. Photo: © RWD
The sepals on Des Entangs' St John's-wort are somewhat unequal.


23rd Aug 2015, dirt track, nr. Warrington, Cheshire. Photo: © RWD
The sepals and petals on Des Entangs' St John's-wort are not largely bereft in black dots (or even black striations).


23rd Aug 2015, dirt track, nr. Warrington, Cheshire. Photo: © RWD
But Des Entangs' St John's-wort are also supposed to have sepals which are minutely toothed, but your Author cannot see any minute teeth.


23rd Aug 2015, dirt track, nr. Warrington, Cheshire. Photo: © RWD
Des Entangs' St John's-wort still have the black dots and translucent white dots of Perforate St John's-wort


23rd Aug 2015, dirt track, nr. Warrington, Cheshire. Photo: © RWD
Said to be the main identifying feature of Des Estangs' St John's-wort the alternating round and then square parts of the stem, here round, square, round, square and round again, changing at stem junctions.


Hybridizes with :

  • Wavy St John's-wort (Hypericum undulatum) which was discovered in Cardiganshire in 2015.
  • Imperforate St John's-Wort (Hypericum maculatum) to produce Des Etangs' St John's-wort (Hypericum × desetangsii) which is partially ferrtile and backcrosses to produce a variety of intermediates. It frequently produces those with stems which have 2 to 4 ridges.

It is native amd the most abundant species of St John's-wortin England, but is rare in North scortland. It occurs in dryish grassland, open woods and banks.

Like all St John's-worts it is puroportedly used in folklore medicine, but its' often toxic effects on any other conditions the patient may have are so numerous that this use should be discontinued, unless prescribed by a real doctor who knows what other ailments you may have and which drugs to combat them you may be taking. Mostly, the compounds in St John's-worts interfere with or completely stop many other pharmaceutical drugs the user may be taking from working!

It contains the following substances, amongst many others: AdHyperforin and Hyperforin are Phlorogucinols; whilst Hypericin and PseudoHypericin are Napthodianthrones, plus the Flavonoid Hyperoside (being the 3-O-Galactoside of Quercetin which is also found in Bilberry) and Amentoflavone (amongst half a dozen other Flavonoids).


  Hypericum perforatum  ⇐ Global Aspect ⇒ Hypericaceae  

Distribution
 family8St John's-wort family8Hypericaceae
 BSBI maps
genus8Hypericum
Hypericum
(St John's-Worts)

PERFORATE ST JOHN'S-WORT

Hypericum perforatum

St John's-wort Family [Hypericaceae]