Ceratodon purpureus

Found on a thatched roof in Dorset this bryophyte I first thought was Dicranoweissia cirrata but it had dentate leaf tips. Because of this Bryoerythrophyllum recurvirostrum was considered but this species has papillose leaf cells and doesn't grow on thatched rooves. After consulting experts it was discovered that this species was indeed Ceratodon purpureus. The leaf state when dry prevented me from keying out correctly.

Ceratodon purpureus wet

Ceratodon purpureus dry

Ceratodon purpureus leaf

Ceratodon purpureus leaf section

Ephemeral mosses

I found some small ephemeral bryophytes on a reservoir bank on the weekend. The options were: Pseudephemerum, Ephemerum, Archidium and Pleuridium. I found the key to separate these not that great so have put a few notes here. Pleuridium stands out from the others by having a wide base to the leaf sharply narrowing to a mostly long needle like leaf. Archidium should have non fertile shoots with short sharply pointed leaves, quite distinctive when familiar with. This leaves separating Pseudephmerum and Ephemerum. Pseudephemerum has costate and untoothed leaves whereas the most common Ephemerum (minutissimum) has dentate leaves with no costa. Some of the more uncommon Ephemerum are costate and without maginal teeth. Perhaps only E.recurvifolium with its oblique apiculus of the capsule can be done in the field. Separating the rest may depend on the amount of magnification you have as these plants are tiny. Ephemerum sessile for example can be separated from P.nitidum by spore size; 20-32µm in P.nitidum and 60-80µm in E.sessile. The leaves look longer and thinner on E.sessile compared to P.nitidum so I suspect familiarity with these groups could be useful in the field.

Pseudephemerum nitidum

Ephemerum minutissimum showing the dentate leaf

Camilla atrimana

Plumose arista with long rays above and very short rays below, crossed P bristles and a spine on the ventral side of the fore femur should get you to Camillidae. Only about 5 species on the British list. This one shows a pointed apical section of the wing which suggests C.atrimana. C.acutipennis looks to be lumped with C.atrimana. Caught in Somerset at Crook Peak on 6/9/18

Camilla atrimana

Camilla atrimana

Camilla atrimana

Campsicnemus curvipes

Uniserial acrosticals, dorsal arista, frons narrowing towards the antennae and then widening below are some of the signs to identify Campsicnemus.

Campsicnemus curvipes

Campsicnemus curvipes

Campsicnemus curvipes

Priocnemis fennica

Found at Westhay Moor NNR on 19th August 2018. Identified as the spider hunter Priocnemis fennica.

Priocnemis fennica

Priocnemis fennica

Priocnemis fennica

Priocnemis fennica tarsal claw

Stigmella oxyacanthella

Mines of Stigmella oxyacanthella found in Sand Point NT car park on Hawthorn on 27th August 2018.

Stigmella oxyacanthella mine on Hawthorn