Fissidens crassipes subsp. warnstorfii?

I popped out at lunchtime to finish off tetrad SO30C which I started late last year. My 2018 visit focussed on upland-edge woodland and streams, so today's targets were species of walls, tracks and trees. The canal bridge at Goetre (SO314057) seemed as good a place as any, and produced 32 additions to the tetrad. Highlight was what I thought was Fissidens fontanus submerged in the canal - a single 2x2cm tuft of long, narrow shoots about 2cm below the water surface.  However, I could see a leaf border through the hand lens and I didn't think F. fontanus was bordered, so I collected 3 shoots for checking.

 

Sure enough, Fissidens fontanus is unbordered, and working my plant through the key in Smith took me to F. crassipes.  The canal plant was unlike any F. crassipes I had seen before, and I am very familiar with the short (<1cm long) plants of this common lowland moss.  Just in case, I checked the text in the European guide of Frahm & Frey (ed Blockeel), and there found three infraspecific taxa of F. crassipes.  One of these - var. philibertii - matched the canal plant very well, with shoots >2cm long (vs up to 1cm in var. crassipes), and with the upper part of the lamina shorter than the sheathing part.

 

the two blue bars are the same length, showing the upper part of the leaf
is shorter than the sheathing part

Frahm & Frey mention four synonyms of var. philibertii: var. submarginatus, Fissidens warnstorfii, F. mouretii and F. sublineaefolius.  This showed that several people have considered this taxon to be sufficiently different to typical F. crassipes that it deserved species rank.  A quick check of Tom Blockeel's account in the Atlas indicated that this distinctiveness is currently recognised at the subspecies level, with World Fissidens expert Maria Bruggeman-Nannenga calling it subsp. warnstorfii.  The Atlas describes this as a Mediterranean plant, and I have not yet managed to find any reference to it being recorded from Britain before.  I doubt that many of the boats that ply the canal have come here from the Mediterranean, but introduction via aquatic plants seems plausible.  Alternatively, the Monmouthshire plants might be a morph of subsp. crassipes that grew very tall under the shade of the canal bridge in last summer's drought, but if that is the case it seems surprising that it would so closely resemble the Mediterranean subspecies of this moss. 

Horns a-plenty

On Fridays I mostly look after my younger daughter Amy, but I do get a couple of hours of play time while she is in nursery school - ideal for topping up the bryo counts for some local tetrads. On Friday last week conditions were ideal - some morning rain to moisten up the bryos nicely after the recent dry spell, replaced by sunshine by the time I ventured out.

My target was the west (VC41) bank of the River Rhymney north of Llanedern Bridge. I looked at a short section south of the bridge a year ago but only managed 30 taxa, so wanted to try and bump this up a bit. The usual range of flood zone bryophytes was present, including plenty of fruiting Leskea polycarpa. Of more interest to me were some large patches of fruiting Fissidens crassipes on riverbank rocks (convincing microscopically, with cell and peristome measurements within the ranges given in Smith), the first time I've seen this species on the local rivers.

A patch of knotweed on the riverbank had been chemically treated, allowing bryophytes to flourish on the newly-created bare ground. Both Riccia glauca and R. sorocarpa were present here.

Riccia glauca

Riccia sorocarpa

The best was still to come though. Across the track from the river was a large, grassy arable field and here, along with more crystalworts, were two species of hornwort: large male and female rosettes of Phaeoceros laevis and much smaller rosettes of Anthoceros with well developed horns. Frustratingly, try as I might, I couldn't find any male organs on the Anthoceros sample I brought home, so it will have to go down as Anthoceros sp. (though it's very likely to be A. agrestis as the rosettes were small). Other typical arable bryos were also abundant: Ephemerum minutissimum, Dicranella scherberiana, Trichodon cylindricus and Tortula truncata.

Anthoceros sp.

Anthoceros rosettes

Phaeoceros laevis (female)

Phaeoceros laevis (male)

Phaeoceros laevis (male organs)

I still haven't quite got this tetrad up to 60 species, but perhaps Sam has some records from the eastern (VC35) half?

A quick splash in the Honddu

A 20 minute window before collecting two visitors from a train in Abergavenny gave me a chance to visit the Honddu at Pandy, and to finish off tetrad SO32G which I started on the hills in the early 2000s.  Fissidens crassipes (photo), F. pusillus, Hygroamblystegium tenax and Rhynchostegiella teneriffae were on sandstone rocks, forming part of the typical riverine assemblage in SE Wales.  Several epiphytes, including Leskea, Orthotrichum striatum, O. tenellum, Syntrichia papillosa and Ulota crispa, bruchii and phyllantha were also new for the tetrad.

Rhynchostegiella teneriffae was also present in a stream just east of Abergavenny (SO31C), which I knocked off in my lunch hour, and the same valley also held fragments of tufa that supported Eucladium and Didymodon tophaceus.  Finally, a railway bridge had some Schistidium elegantulum alongside abundant S. crassipilum.

So, two more VC35 tetrads up to par.  Still over 1/3 remain unrecorded though.