Sunday, May 24, 2009

Bird’s-eye Primrose
















Between Teesdale's High Force waterfall (see yesterday's posting) and the waterfalls at Wynch Bridge (bottom picture here) you can also find the diminutive bird’s eye primrose Primula farinosa, growing in shallow patches of soil on wet rock ledges close to the river. Their small leaf rosette and flower stalk is covered with waxy scales, known as farina, which make the plant easy to identify even when it isn’t in bloom. The flower shape, size and intensity of colour is variable in this species because, like the common primrose, there are two different forms of flower in the population, which ensures that the plants are cross-pollinated rather than self-pollinate, and so produce very variable offspring. Take a close look at the flowers in the top and second from top pictures here (double-click the image for a larger view). In the top plant you can see a ring of five stamens, which dispense pollen, at the top of the flower tube. The stigma, which receives pollen, is hidden way down inside the floral tube. In the plant in the second picture the single stigma is at the mouth of the flower tube and the stamens are hidden from view within. This differential positioning of stamens and stigmas in different individuals ensures that visiting insects cross-pollinate the flowers.

4 comments:

  1. I don't think I've ever seen one of these before Phil.
    Beautiful little flower.

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  2. It's a lovely little plant Keith, and also grows at higher altitudes in Teesdale, up at Moor House Nature Reserve where the spring gentians are, on the gravelly edges of streams.

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  3. Great photos of a species i`ve never seen, either.

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  4. Are their seeds carried and distributed by the stream if they occur only on the water's edge? I spent many happy days paddling in the Tees near the Wynch Bridge when I was a kid on family trips. This was before Cow Green reservoir was built upstream and it was not uncommon for us to have to beat a hasty retreat as the river level rose rapidly after rain in the hills. I wonder if the primrose distribution has changed post-reservoir given that flash flooding is much rarer?

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