Hybridizes with :
- Chiltern Gentian (
Gentianella germanica) to produce (
Gentianella × pamplinii) which is highly fertile (50%).
Early Gentian (
Gentianella anglica) to produce (
Gentianella × davidiana)
Dune Gentian (
Gentianella uliginosa) to produce (
Gentianella amarella var. uliginosa)
There are also three subspecies (the fourth is doubtfully worth sub-species status):
None of the above photographs are anything but pure Autumn Gentian, since none occur anywhere near the location of these specimens.
Gentianella amarella subsp. amarella which has main stems having between 4 and 9 branch-pairs and is frequent is locally frequent in Britain south of Angus.
Gentianella amarella subsp. hibernica present in only very few locations north of Scarborough, and a few extra locations in Western Ireland. This subspecies is usually narrower leaves which are less tapered than the above and has between 7 to 11 branch-pairs on the main stem. It is a [RR] quite rare.
Gentianella amarella subsp. septentrionalis with an interrupted presence north of Lancaster. This has only between 2 and 7 branch-pairs on the main stem. This subspecies is also a [RR] quite rare.
Gentianella amarella subsp. druceana. This has only between 2 and 5 (unusually 6) branch-pairs on the main stem with narrower leaves. This subspecies is also a [RR] quite rare but should maybe be taken as ssp. septentrionalis.
Some similarities to : Field Gentian (
Gentianella campestris) but this has paler and bluer flowers than Autumn Gentian, often being almost white. Field Gentian also always has four petals whilst Autumn Gentian usually has five (but can have four even on the same plant).
Some resemblance to :
Centauries such as Common Centaury (Centaurium erythraea) but that has smaller pinkish flowers and to Yellow-wort (Blackstonia perfoliata) but that is yellow.
In flower from near the end of July to just after the beginning of October.
Habitat: grows on old sand dunes and on alkaline grassland, such as limy soils. As shown here it is growing on an ex-alkali works, now an SSSI.
Many of the natural chemicals below are to be found not only in Autumn Gentian, but also in many other members of the Gentianaceae Family, as well as many other similar compounds which are not found in Autumn Gentian.
The roots of Autumn Gentians contain: the yellow
Gentisic Acid (5-dioxybenzene), and at least four xanthones:
Gentisein (1,3,7-triHydroxyXanthne) [note - Gentisein should not be confused with Genisteine, which is an isoflavone], Gentisin (1,7-Dihydroxy-3-methoxyxanthone), and the very bitter xanthone glycoside Gentiopicrin (aka Gentiopicroside).
A BENZOIC ACID
The yellow Gentisic Acid is present in the roots of Autumn Gentian and is a derivative of
Benzoic Acid, being dihydrobenzoic acid.
In the human body it is a minor metabolic breakdown product of aspirin, and is excreted by the kidneys after aspirin has been taken. The potent anti-oxidant activity of Genistic Acid may account for the anti-atherogenic properties of aspirin. (That is, it is useful against the atheromatous plaques which accumulate on the walls of blood vessels in atherosclerosis).
Xanthone itself has no reported presence in the Gentian Family of plants, and is shown here only for comparison but the derivatives of Xanthone shown below it are all present in Spring Gentian.
Xanthone itself acts as an insecticide and is used as an ovicide to kill the eggs of
Codling Moths, and as a larvicide to kill larvae. Xanthone derivatives are often brightly coloured, such as the yellow-coloured LicheXanthone found within some lichens. (
Xanthenes, on the other hand, are similar chemically, and often used as dyes, but are not present in Gentians).
Gentisin is mutagenic and also exhibits strong Monamine Oxidase Type A and Type B inhibition.
Several other xanthones have also been isolated from Autumn Gentian. The xanthone glycosides, Veratriloside, Corymbiferin 1-O-glucoside, Swertianolin and Norswertianolin along with two newly discovered xanthone glycosides: Corymbiferin 3-O-β-d-glucopyranoside and the glycoside of a dimer of xanthone: Swertiabisxanthone-I 8'-O-β-d-glucopyranoside (shown below).
Swertianolin (above) is the 8-O-glucopyranoside form of
Bellidifolin (not shown), which exhibits Monamine Oxidase B inhibition. In the Indian system of medicine, the presence of Swertianolin and Norswertianolin in the non-native (to the UK) plant
Swertia purpurescens are attributable to its medicinal properties.
Also present are the xanthone glycoside
Triptexanthoside C and a xanthone dimer
The prefix seco- derives from the Latin secare which means cut and in chemical nomenclature denotes the cleavage of a ring by the addition of one or more hydrogen atoms. The Secoiridoid compounds are variations on the iridoids, which are terpene derivatives and contain no nitrogen. The secoiridoid glycosides are present in greater amounts than the xanthones. There are many other Secoiridoid Glycosides.
Gentiopicrin is synonymous with Gentiopicroside, and 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 hepatic and gall-bladder disease. Also as an adjunct to chronic inflammatory disease.
Gentians are intensely bitter which is due to the secoiridoid glycoside compound
Amorogentin, even though Gentiopicroside, another bitter secoiridoid glycoside, is present in much greater amounts. This as the result of amorogentin being 3000 times more bitter than is Gentiopicroside.
Amorogentin may find use as a treatment for Leishmaniasis.
Gentiodelphin is an anthocyanin blue pigment present in Gentian flowers. It has the anthocyanidin Delphinidin (shown in cyan) at its core, surrounded by three
glucose moieties (shown in red) to which two Caffeic Acid groups are attached (shown in green). Gentiodelphin is unusually stable - the extra units surrounding the anthocyanidin help to stabilise the molecule. Gentiodelphin is a deep-blue colour. One of the Caffeic Acid moieties bestows upon it that extra blueness typical of gentians.
The deep violet dye
Gentian Violet used in the biological laboratory is NOT contained within Gentians, but is rather named after the colour of Gentians. Gentian Violet is also a fungicide and anti-septic used to treat skin fungal infections and wounds, but stains the skin a bright purple so is not used as much now as it used to be; there are less conspicuous and more effective alternatives.
Gentian Violet (aka Crystal Violet and Methyl Violet 10B is one of a family of three differing Methyl Violet dyes, the other two being Methyl Violet 2B and Methyl Violet 6B. Indeed, the name Gentian Violet once referred to a mixture of Methyl Violet dyes, but now the term is used solely in relation to Methyl Violet 10B, and more generally as Crystal Violet to avoid possible confusion. It destroys cells and also binds to DNA, so is potentially mutagenic and should never be taken internally.
Note that it is not 120°-symmetric, but only bi-symmetric. Also, it is a polar molecule, with charges separated (note the chloride ion), and does NOT occur naturally.