Sunday, 19 April 2015

Hygrohypnum query

I found this tiny sample among a collection from a stony forestry track margin at Cefn Mably Wood, NE Cardiff, last weekend.

The curved, concave leaves suggest Hygrohypnum, and the inflated alar cells also seem to fit with it being a member of this genus.

The habitat was dry and probably calcareous (Dicranella varia was an associate), suggesting H. luridum as the most likely species. However, there is no trace of a nerve, which I think is always a feature of this species. The other Hygrohypnum seem unlikely given the habitat, so perhaps I'm barking up the wrong tree and it's not Hygrohypnum at all. Any suggestions welcome, thanks.


  1. Odd, most odd! It may be Calliergonella cuspidata, strange though that may seem. That species' relative C lindbergii is falcate. The hyaline alar cells suggest Hygrohypnum ochraceum, but I'm sure it can't be that. I don't think it's a Hypnum and cannot come up with any other plausible alternatives.

  2. Well, I'd never have got there, but I think you must be right. The shoot tip in particular looks like a slightly unfurled Cal cusp, and not at all like Hygrohypnum. It's just odd that the leaves further down the shoot are curved.

    There was plenty of Cal cusp nearby, and I'm sure if this fragment had been attached to the rest of the plant it would have been obvious that that's what it was.

    Thanks again.