HOUND'S-TONGUE

Cynoglossum officinale

Borage Family [Boraginaceae]  

month8May month8jun month8june month8jul month8july month8Aug

status
statusZnative
 
flower
flower8red
 
inner
inner8indigo
 
morph
morph8actino
 
petals
petalsZ5
 
type
typeZbell
 
stem
stem8round
 
smell
smell8mousey smell8roast peanuts smell8roasted peanuts
mousey
toxicity
toxicityZmedium
 

31st May 2007, Walney Island (south), Barrow in Furness, Cumbria. Photo: © RWD
Grows in a single clump.


14th June 2011, Ainsdale, Sefton Coast, Lancs. Photo: © RWD
Normal stance is for the flowering stalk to slope downwards, the flowers even more so.


14th June 2011, Ainsdale, Sefton Coast, Lancs. Photo: © RWD
Bird's-eye view, flowers mostly hidden, angled ground-wards.


31st May 2007, Walney Island (south), Barrow in Furness, Cumbria. Photo: © RWD
Flowers never fully open properly.


31st May 2007, Walney Island (south), Barrow in Furness, Cumbria. Photo: © RWD
Plant covered in short whitish hairs.


31st May 2007, Walney Island (south), Barrow in Furness, Cumbria. Photo: © RWD
Many flowers emerge on alternate sides of the tops of the stems.


31st May 2007, Walney Island (south), Barrow in Furness, Cumbria. Photo: © RWD
The flowers are deep red, sometimes purple tinged, with five petals. They rarely open fully as here.


31st May 2007, Walney Island (south), Barrow in Furness, Cumbria. Photo: © RWD
Flowers usually facing downwards.


14th June 2011, Ainsdale, Sefton Coast, Lancs. Photo: © RWD
Petals veined a beetroot red.


31st May 2007, Walney Island (south), Barrow in Furness, Cumbria. Photo: © RWD
With withered flower in the centre, four nutlets grow within the five sepals.


14th June 2011, Ainsdale, Sefton Coast, Lancs. Photo: © RWD
The nutlets grow up the stem in sets of four with a green spike growing up between them.


14th June 2011, Ainsdale, Sefton Coast, Lancs. Photo: © RWD
The nutlets turn a beetroot colour. The thrusting spike between angles them outwards


19th July 2007, Walney Island (north), Barrow in Furness, Cumbria. Photo: © RWD
Gone to fruit. The nutlets have short barbed projections from the periphery to facilitate dispersal by animals. Occasionally ornamental, in gardens. Like anti-bonding δ-orbitals, or mis-shapen custard cup-cakes.


14th June 2011, Ainsdale, Sefton Coast, Lancs. Photo: © RWD
A light-green spike thrusts up between the four nutlets, loosening them.


14th June 2011, Ainsdale, Sefton Coast, Lancs. Photo: © RWD
The nutlets contain an array of spikes growing upwards, each tipped with a tiny four-way barb ready to be ensnared in the fur of any passing animal as a means of dispersal.


14th July 2014, dune slacks, Freshfield, Sefton Coast. Photo: © RWD
The fruits from the rear, showing the five flower sepals and hairy stems. Note how the flower-stalks start off from the opposite side of the stem and curl around it to face forwards (and slightly downwards)!


9th Sept 2009, dune slacks, Freshfield, Sefton Coast. Photo: © RWD
Basal rosette. Leaves wavy.


9th Sept 2009, dune slacks, Freshfield, Sefton Coast. Photo: © RWD
Basal rosette consisting of many wavy leaves. Minute hairs on leaf edge may look like minute teeth.


9th Sept 2009, dune slacks, Freshfield, Sefton Coast. Photo: © RWD
The leaves have a thin scattering of fine white felty hairs.


Not to be semantically confused with : Black Horehound [a plant with similar name]

Some similarities to : The Comfreys.

Uniquely identifiable characteristics : the appearance; an 18 inch shrub with floppy crinkly hairy leaves and the half-hidden (visible from full-on only) dark-red, nearly brown, flowers.

Distinguishing Feature : If in fruit, the four yellow flattened fruit arranged as in the dots of the 4-side of a dice.

Hound's-tongue is reported as having a strong mousy-type smell or one of roasted peanuts; depending who you ask, folk all smell compounds differently. In the USA it is regarded as a noxious weed, being invasive. Ingestion of the plant by animals can lead to photo-sensitization of the skin probably due to the presence of furocoumarins. Just like Ragwort, Hound's-tongue also contains pyrrolizidine alkaloids which on ingestion are toxic to the liver, also causing damage to the lungs. Death may follow. Horses and cattle are most vulnerable.

Habitat: On sandy and sunny places, often near the sea, likes sand dunes and shingle. Inland on dry rather bare grassy places, liking lime.

PYRROLIZIDINE ALKALOIDS

Hound's-tongue contains four pyrrolizidine alkaloids, cynoglossine, consolidin (consolidine), Echinatine (Indicine) and Heliosupine (an open diester pyrrolizidine alkaloid). The main pyrrolizidine alkaloid in Hound's-tongue is Heliosupine (aka Cynoglossophine), followed by echinatine and consolidine (a gluco-alkaloid, which hydrolyses to a sugar molecule and consolicine) which paralyses the CNS in cattle frogs and vertebrates. Large doses in cattle cause excessive thirst and palsy of the hind legs. Cynoglossine, which is thrice as potent as consolidine, occurs in the roots, and has a paralytic effect similar to the action of curarine (an alkaloid extracted from curare) on frog muscles.

Pyrrolizidine alkaloids are metabolically activated within the liver where they will alkylate both proteins and DNA molecules; they are therefore hepatotoxic causing liver damage, as well as mutagenic, teratogenic and carcinogenic. Substantial ingestion results in inhibition of neurons and paralysis.

The first two, Heliosupine and Indicine, are used medicinally to relieve pain which they accomplish by depressing the Central Nervous System, but are potentially carcinogenic (see above paragraph). A related compound to indicine, indicine N-oxide, (where an oxygen atom is co-ordinate bonded to the shared ring nitrogen atom) is being tested as a drug against cancer.

[Your author is still searching for the structural formulae for cynoglossine, consolicin(e) and consolidin(e), which are all frequently stated as alkaloidal components of Hound's-tongue. Because none are forthcoming the Author can only assume that either they are the older names for more common alkaloids, or that they are unresolved mixtures of alkaloids. Most likely they are pyrrolizidine alkaloids, but that is just a guess].

But there is a solitary hint which your Author found which suggests Cynoglossine could be a trans-isomer of Heliosupine, where the bond upper-left has been swivelled upwards.

Hound's-tongue is poisonous to cattle, which can develop nervous symptoms and diarrhoea from which recovery is unlikely even given 3 months.

No relation to: Hart's-tongue nor Adder's-tongue [plants of similar name, but differing family].


  Cynoglossum officinale  ⇐ Global Aspect ⇒ Boraginaceae  

Distribution
family8borage family8Boraginaceae

 BSBI maps
genus8Cynoglossum
Cynoglossum
(Hound's-tongues)

HOUND'S-TONGUE

Cynoglossum officinale

Borage Family [Boraginaceae]  

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