Monday, 27 October 2014

Fissidens in Pont Rhyd y Fen

Hilary and I saw this small Fissidens yesterday in Pont Rhyd y Fen at the base of an old stone bridge which had a stream running under it. The plants are about 1 cm tall and were growing on the bridge-stone almost on the water line. They were clearly subject to periodic inundation. It's a rather shaded location.

Fissidens at base of stone bridge 

The leaves have a clear, prominent, yellowish border (easy to see in leaves in photo above) and a fairly stout mucro. Photo below shows a low power  microscope view. Again the border looks fairly thick and pigmented and the mucro looks large.

It looks like Fissidens rivularis to me and the habitat is right. Let me know what you think.


  1. The border does join the mucro, which suggests not rufulus or crassipes but separation from monguillonii and curnovii is tricky. The leaf tip doesn't look quite as thick-margined as I'd expect in rivularis, but you're probably correct.

  2. PS the rhizoids look very red, which suggests curnovii to me.

  3. Yes, you're right. I had discounted curnovii because the capsules weren't inclined, but I see in Smith that they are occasionally erect in that species. So Fissidens curnovii it is then. Thanks Sam.

  4. The top right ripe capsule looks pretty inclined too.