Hypericum linarifolium . Flax-leaved St.John's Wort

Flax-leaved St. John's Wort in Northern Portugal

9th June 2017

While on a walking holiday a brief rest stop allowed enough time to photograph a St John's Wort that did not did not look familiar. Only when looking through the photos on returning to Cambridge that I realised that I had been looking at a species I had never heard of, but one that does occur in the UK.

  The flower was typical St John's Wort and I was thinking Perforate St John's Wort as the petals had the black glands and the anthers were yellow, but the stem was round without the two ridges and the leaves were very thin. Something odd about this plant so I took some more photos.

It is always good to get a photo of the underside of a flower and this photos shows the sepals are less than half the length of the petals. The sepals have black glands on short stalks and black lines along the veins. The petals have black glands and red lines on the back. The stem is hairless and the narrow leaves are opposite on the stem and have the black glands but no translucent dots.

The leaves on the very upright stem were very narrow, almost like the Irish St John's Wort seen in Glengarriff , West Cork, but they only have three veins which run parallel up the leave and these have a more normal vein pattern.

Final shot of flower shows the five petals and the stamens , over 30 with yellow anthers. You can just make out the two of the three divergent styles with the red tips almost horizontally sticking out each side.

Hypericum linarifolium (  Flax-leved St John's Wort ) has a distribution from the North of Portugal , north through Spain and the western edge of France , especially Brittany and runs out with populations on the Channel Islands and just a few places in England and Wales as its most northern limit. Its stronghold in England is South Devon with a few outposts in Cornwall and Wales. It is also found on Maderia.

A full description of Hypericum linarifolium was found on line in the Journal of Ecology 1963 by R.B. IVIMEY-COOK.

This plant was found on 1st June on the granite hills near Chorense, Northern Portugal, on the old Roman Road.  Thanks to On-Foot Holidays for suggesting the route.
Trailing St John's Wort was also present on this Road.


Peter Leonard  9th June 2017