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Hypericum perforatum

Hypericum perforatum

Claire continues with the medicinal plant diversity series:

Thank you to Marianne (marcella2@Flickr) of Alkmaar, Netherlands for this gorgeous photograph of Hypericum perforatum, or St. John's wort, provided via the BPotD Flickr Pool. Zeer gewaardeerd!

Hypericum perforatum is known as common St. John's wort -- the name "St. John" stems from the traditional harvest time of Hypericum perforatum during the day of St. John on June 24th. The species belongs to a genus that includes a whopping 370 species worldwide. It has spread, via introduction, to temperate and subtropical regions in North America and Asia, with origins in Europe. Sadly, it is an invasive species or noxious weed in many countries, particularly because it is very toxic to livestock and can be lethal.

Contrasting to the effects it can have on animals, Hypericum perforatum's primary medicinal application is treatment for mild to intermediate forms of depression. It has also been used for less serious maladies like scrapes and cuts (early studies show some positive results for having antibacterial properties against gram-negative bacteria). The most medicinally-active chemicals in Hypericum perforatum are hypericin and hyperforin, which have proven to be effective in treating depression . These chemicals may function as inhibitors of monoamine oxidase, a compound associated with the illness. A study published in the Cochrane Database of Systematic Reviews suggests common St. John's wort is more effective than a placebo and equivalent to tricyclin antidepressants for short-term treatment. St. John's wort contains many other compounds (including oils, tannins, and flavinoids) that have been suggested as medicinal, though further research is needed.

Hypericum perforatum can be a lovely ornamental in gardens, drank as an herbal tea (though the taste, I was told, is a bit peculiar) and produces colours for dyes: a pleasant purple when the buds and fruits are crushed and yellow when the flowers are used. Needless to say, this is an intriguing and important species that could take some more looking into!


I had heard of the name's origin as referring to one of the medicinal herbs attributed to St. John, similar to the word 'wort' referring to a curative element such as in lungwort and liverwort.

And a significant noxious weed in Australia where it runs rampant with no pests or diseases

It's a very pretty dense evergreen groundcover that creeps underground and can go through rockeries. It needs a lot of sun and dry soil. It will crowd out anything else. It is subject to rust, at least it is in the Pacific Northwest.

I live in the Pacific Northwest. The previous owner of our home planted this all over the place in my gardens. It is very difficult to root out--I have been trying to get rid of it for ten years. Anything I try to plant will be overtaken by it if I am not vigilant. I am not a fan of this plant.
The anti-depressant qualities of the plant are surely overcome by the depressing qualities of the plant for a gardener.
There are many more beautiful edible and less aggressive plants to plant in the Northwest than this one, in my opinion. Among them would be rosemary, oregano, blueberries, sage, etc. which are all thriving in some harsh winter temperatures at this time.

Oh! Stunning! Not making light of depression, this flower is enough to distract me completely from sad thoughts ... if you really want to be rid of it, you could try suffocation with carpet.

There seems to be two or three different plants with this name, are you sure this is the botanical?

There are many plants (370 in the genus Hypericum) with the common name St. John's wort (or St. Johnswort). The weedy evergreen groundcover planted in the PNW is Hypericum calycinum, which is also known as creeping St. Johnswort or Aaron's beard. Hypericum perforatum is also a weed, more of a rangeland/grassland than forest, and another common name for it in the PNW and northern California also as klamathweed (it was a very bad weed in Northern Cal-Southern Oregon Klamath Region, until a cute golden beetle was introduced as a biocontrol; now it's a low-level weed kept in check by its predator).

if you are a garden plant,you are regarded,well regarded, just
as long as you stay in the garden. davies gilbert

before ingesting plants as a form of natural remedy -homework needs
to be done and a lot of it plants can just as lethal to humans as
they are to animals.

the picture is just fine as are the comments today great group

The buds of this flower are used in Sweden to give the vodka a nice color and a slightly bitter taste. It is used as a digestif or schnaps to go with the herring and crayfish (in August. This concotion is also called "hirkumpirkum"

I see this along logging roads blooming in late summer, and will pinch off a flower or two to suck on. You can definitely feel a mild calming effect.

The tea applied to insect stings or spider bites can take away the itching and inflammation within minutes. Happily, the plant is native here in the UK and does usually flower a few days before St John's Day.

There are other species that are medicinal. For example, Hypericum androsaemum, the Tutsan, whose common name means "All Heal".

I believe i remember reading that Hypericum is a photosensitizer, making animals, and presumably humans, prone to skin damage in the sun.

OTOH, there is a very odd characteristic of this plant that can be discerned in this photograph. I first noticed this a long time ago, but I have never seen another plant, not even another Hypericum, that shares it. Just as different species of twiners characteristically go either clockwise or counter-clockwise, flowers with imbricate petals also have a characteristic "direction," except for this species. Since the petals are slightly asymmetrical (one edge straighter and with fewer "dots"), you can see that there are two CW and one CCW flower in the illustration.

There is an annual hypericum where I grew-up that is really weird: Hypericum gentianoides, which has only scale-like leaves, and looks kind of like an Ephedra.

As beautiful and useful as this plant is, remember that it is considered and invasive species in the United States as well:

Be aware of this if you have it in your garden. Since it is the flowering tops that are useful medicinally, be sure to harvest all of the flowers and not let any of the plant go to seed. It is also helpful to plant it in a container so that it cannot spread by rhizomes.

Yes it can cause photosenstivity when taken orally, and especially when applied topically. Be sure to protect skin from sun exposure when using St. John's wort creams or ointments.

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