FIELD ERYNGO

WATLING-STREET THISTLE

Eryngium campestre

Carrot Family [Apiaceae]

month8jul month8july month8aug

status
statusZarchaeophyte
flower
flower8white
inner
inner8green
morph
morph8actino
petals
petalsZ5
type
typeZglobed
stem
stem8round
stem
stem8ribbed
contact
contactZlowish
rarity
rarityZrare

2nd Sept 2013, Kent. Photo: © Dawn Nelson
A very rare plant, growing to 80cm, taller than Sea Holly (Eryngium maritimum) with thinner and longer branches.


2nd Sept 2013, Kent. Photo: © Dawn Nelson
Leaves pale-green, stems paler, no hint of steel-blue anywhere.


2nd Sept 2013, Kent. Photo: © Dawn Nelson
Spent flower heads much smaller (1 to 1.5cm across) than those of Sea Holly and are pale-green with spiny projections.


2nd Sept 2013, Kent. Photo: © Dawn Nelson
Flowers in almost globular umbels, sometimes slightly egg-shaped. Each floret has 5 short white petals. Bracts underneath each flower-head are leaf-like and prickly.


2nd Sept 2013, Kent. Photo: © Dawn Nelson


2nd Sept 2013, Kent. Photo: © Dawn Nelson
The five short petals are strongly recurved. Bracts underneath a paler green with short felty hairs.


2nd Sept 2013, Kent. Photo: © Dawn Nelson
Stems very pale green and ribbed. Spiny leaves/bracts at the branch junctions.


Not to be semantically confused with the genus : Erysimum [plants with similar names belonging to the Cabbage Family (Brassicaceae) such as Wallflower and Treacle Mustard]

Some similarities to : Sea Holly (Eryngium maritimum) to which it is directly related.

Uniquely identifiable characteristics

Distinguishing Feature : Like Sea Holly (Eryngium maritimum) but much smaller globular flower-heads, leaves spiny and pale-green with no hint of steel-blue on the plant anywhere.

Sea-hollies are atypical umbellifers where the umbel is not recognisable as such. It is very rare and should not be disturbed. Inhabits grassland and dry open places, mostly near the sea and especially on calcareous soils. Extremely localised occurring in very few places in the south of England, especially on the Roman road called  Watling Street as it passes through Dartford, Kent, where presumably these photographs were taken by Dawn.

The roots were formerly boiled as a vegetable or candied to eat as sweets. But the plant is very rare now and it is illegal to uproot it. It was also used medicinally as, variously, an antitussive, diuretic, appetizer, stimulant and aphrodisiac and to treat coughs, whooping cough and urinary infections. It contains an essential oil plus saponins and tannins.

The major components of the essential oil are α-Pinene and the aldehyde (Z)-3-Hexenal, the latter having an intense green odour of freshly cut grass and acts as an attracting pheromone to many insects. It is responsible for part of the aroma of Apples and is used to flavour vegetable and fruity food and in perfumes.

MONOTERPENE GLYCOSIDES


The 3-(-D-Glucopyranosyl -OxyMethyl) glycosides of the triple methyl derivative of CycloHexanone and of CycloHexadienone , which are both monoterpene aldehydes. It is quite possible these two glycoside terpenoids are responsible for some of the taste and medicinal properties of Field Eryngo.



TRITERPENE GLYCOSIDES


The saponins of Eryngium species consist mostly of the polyhydroxylated Oleanene type of triterpenoid saponins.

For Field Eryngium these consist mainly of numerous differing glycosides of Barrigenol derivatives. Shown is just one of the many triterpene steroidal Barringenol bases, A1-Barringenol. The saponins (glycosides of these) have two or three glycoside units and several other side groups.

Field Eryngo is also said to contain Agasyllin and Aegelinol, the latter being the Angelic Acid ester of the former. Unfortunately, there seem to be two competing formulae for the both, the one set linear FuroCoumarins, the other set Linear PyranoCoumarins. It could be that the one can turn into the other, but there are two hydrogens left over. Or it could be that the people who tried to identify them drew the wrong structural conclusions. Which is right is open to speculation. But your Author now favours the latter: pyranocoumarins. One source says there are both FuroCoumarins and PyranoCoumarins within Field Eryngo, but does not list them specifically.

LINEAR FUROCOUMARINS


One sources says that the roots contain the linear Furanocoumarins Aegelinol and Agasyllin which have anti-biotic properties. Like all furocoumarins, there is every reason to suspect that these furocoumarins are also photo-toxic, meaning that if the sap gets onto your skin and the skin is then exposed to the sunshine, an allergic reaction will be generated at that site, which could be very bad. Furocoumarins interfere with DNA putting a spanner in the works of all the cells exposed to it.

LINEAR PYRANOCOUMARINS


The flavonoids Astragalin, Rutin, IsoQuercitrin, Quercitrin and Quercetin


  Eryngium campestre  ⇐ Global Aspect ⇒ Apiaceae  

Distribution
 family8Carrot family8Apiaceae

 BSBI maps
genus8Eryngium
Eryngium
(Sea-Hollies)

FIELD ERYNGO

WATLING-STREET THISTLE

Eryngium campestre

Carrot Family [Apiaceae]