SD86 - 23 - SD8216a -Settle Market - east - Trapelia coarctata

Perseverance!

I found a new lichen for me in SD86 whilst collecting (for Christian Aid) in Settle Market Place.

I had thought there were very few lichens at all in the market place, but on the sandstone capstones of the wall next to HSBC bank there was quite a variety of crusts.

The reason I decided this lichen could be Trapelia coarctata is because of the "teeth" round the rim of the apothecia. and the thallus was a pale pinkish fawn colour. The pale rims of the apothecia had teeth. The areoles are about the same size as the apothecia. 

Trapelia coarctata is on the right and is pinker than it appears in this picture.   The picture is 1.8 cm across

It reminded me of the Trapelia coarctata I shad seen in Monigaff Churchyard with a BLS tip to Newton Stuart and it reminded me of a picture Bob Vaughan had shown in the Lichen Zoom-Improvement group of some he had found on brick in London. Well if it can grow in London it can grow in Settle.

The lichens are on the sandstone capstone of the wall next to the HSBC bank in Settle,  next to the red bag.

It's the pale pink patches in the centre foreground on top of the sandstone

Trapelia coarctata - I tried wetting it. the discs should have gone red but they didn't

Trapelia coarctata - closer up: See the teeth

I tried testing it with KOH and Bleach. Not much seemed to happen. A specimen I had been shown in Scotland three years ago had turned a drop of bleach pink. So why had my specimen not turned pink with bleach? 

I went back today with fresh bleach (Milton) and applied two drops to the thallus. With a lot of imagination one could say they went slightly pink, at least bits of the areoles in the thallus did very briefly. But equally, if you were trying to persuade me that there was no reaction I could believe you.

You can see where I have added the bleach - but are these areas pink/red?

I'm not going to give up!

I went back this evening (29 May) with some "Easy - Seriously thick bleach - original" poured fresh into a little bottle and a toothpick.

Yea!  Pink!

You have to look as you apply the bleach because the colour rapidly fades.

white tissue retains the pink stain

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Here are some pictures I have of Trapelia coarctata from elsewhere:

1. From Bob Vaughan on Brick in London: (from our Zoom-Improvement Group)

2. From Monigaff Churchyard,  Newton Stewart (a BLS trip)

Trapelia coarctata at Monigaff, Newton Stewart

3.  picture in my collection labelled Trapelia coarctata  on BLS trip (Ardwell)

 - showing   turning red/pink with bleach

Text from Alan Silverside at Last Dragon:- 

Thallus white to pale or blueish or pinkish grey, thin to moderately thick, continuous or somewhat cracked, more rarely more dispersed-areolate, testing C+ red with bleach, lacking soredia or isidia; apothecia small but sometimes swollen when wet, red-brown, black when dry, forming within the thallus surface and initially looking more like immature perithecia or pushing up to form white spots, when mature with white, halo-like, often ragged, residual rims of thallus. Widespread and locally common on siliceous rocks, brick and stonework.

Perseverance in standing my time collecting - people donate if you put in the time.

Perseverance in looking round, wherever you are. There is so much to see if you only look

Perseverance in finding some bleach that worked.