Toninia aromatica

I spent some time with this one and a had difficulty coming to a satisfactory conclusion. All the clues were giving me several options none of which seemed right at first but a photo of a Toninia following a saxicolous crack got me finally to the right group. Other groups considered were Catillaria, Cliostomum and Lecania. The reaction of K+ y put Cliostomum in the picture but it turned out to be a red herring. The spores are 17µm long and 3-septate. The paraphyses are with a swollen apex with pigmented tip.

Toninia aromatica

Rinodina bischoffii

A lichen that looks on first inspection to be lecanorine but the apothecia section shows it to be lecideine. The 16x11µm spores are quite distinctive so getting to Rinodina was quite easy.

Rinodina bischoffii

Rinodina bischoffii spores

Oxyrrhynchium hians

Oxyrrhynchium hians is a common pleurocarp which can be identified quite readily with care and a good hand lens in the field. With the example below I could see through the hand lens the nerve extending past the half way mark but not reaching the tip and the margin of the leaf toothed. A good feature for O.hians is the leaves being spaced out along the stem.

Oxyrrhynchium hians leaf

Oxyrrhynchium hians

Woolly Fringe-moss - Racomitrium lanuginosum

Found on Dartmoor this common species is quite forward to identify. Under the microscope the long wavy cells identify the group as Racomitrium. Grimmia also has wavy cells but these are short. Racomitrium lanuginosum has 90 degree projections on the white hair point which is visible with a high powered magnifying glass.

Racomitrium lanuginosum

Racomitrium lanuginosum long wavy cells

Racomitrium lanuginosum close up of hair point

Cerastium pumilum - Dwarf Mouse-ear

Cerastium pumilum and Cerastium semidecandrum are similar with the bracts being the best feature to separate the two. C. pumilum has a narrow translucent border and C. semidecandrum has a much larger translucent area.

Cerastium pumilum

Cerastium pumilum bract

Polygonum aviculare - Knotgrass

I found this plant today which I knew was Knotgrass but thought it would be fun to find out which. As it turned out it was rather more difficult than I imagined. It was the key in Stace that got me to the conclusion in the end by the 3mm length of the achene (dry fruit of a flowering plant). There was a mention of silvery sheaths later turning brownish in Domino Guides which I could see. Polygonum arenastrum (Equal-leaved Knotgrass) is the one I had most trouble with. P.arenastrum is said to have leaves on the stem and branches roughly the same but the leaves on the stem were different sizes making this feature difficult to determine. Maximum size of achene on P.arenastrum is said to be 2.5mm therefore not my plant.

Polygonum aviculare achene 3mm in length

Polygonum aviculare

Bilimbia lobulata

This is a lichen I re-examined and after several hours was glad I did as the outcome turned out to be different from the first. Description wise it's a granular thallus with black .75mm lecideine apothecia that are merging to create larger looking apothecia. It's growing on the top side of a brick wall. If you remove some of the lichen you can see that the underside is white. An apothecia section reveals 3-septate ascospores measuring 15µm x 4µm (too small for sabuletorum). The hymenium is brown measuring up to 90µm in height.

Bilimbia lobulata