Ginny B's picture

Hydropunctaria maura

Observed: 29th June 2012 By: Ginny B
S159 Neighbourhood Nature - course complete
Ginny B’s reputation in Fungi and LichensGinny B’s reputation in Fungi and LichensGinny B’s reputation in Fungi and Lichens
Hydropunctaria maura
Verrucaria sp on south side

Crusty, deeply cracked, black lichen on granite just above high tide level. Pictures 1 and 2 are on the south-facing side of the rock; picture 3 is on the north-facing side where it is much thinner, but in the cracks in the rocks it looks like a miniature version of that on the south side. It is much harder to see the fine texture on this side.


Caution: Do NOT use iSpot to identify fungi to eat!

Some fungi are very poisonous so a mistaken ID could have serious consequences.

Species interactions

No interactions present.


synan's picture


I looked at quite a bit of Hydropunctaria (previously Verrucaria) in Wales earlier this month. I don't claim to know it well, but pics 1 & 2 look odd to me, seeming too thick and minutely textured. H. maura is described as 60-300μm (0.06-0.3mm). I'm trying to make it dried and cracked-up Lichina confinis.

The last photo looks more like the real thing, at least from a distance. Pyrenocarp king Alan Orange has recently muddied the water with the introduction of H. oceanica and H. orae, and naming the species demands close examination, if not microscopy.


AlanS's picture

and now ...

Ginny B's picture

Thanks for trying to help

Thanks for trying to help.

I've been re-looking at as many pictures as I can find trying to discover something similar to my photos and to be honest there isn't anything that really looks like them!

From looking at pictures of Lichina confinis, I really don't think it is the same. All the pictures of that one seem to have some branching-like form, whereas my find doesn't seem to have anything like that, unless it requires a microscope to see it.

To give you an idea of size, when you click on picture 2 that is just about life size, but next time I'm out there I'll take something to make measurements.

synan's picture

I know what you mean

I'm not entirely convinced about Lichina confinis either, unless this photo (click for link) truly is that species. I would have thought the branching would be more obvious in your photos; it is to the eye, at least with a hand lens. However, the fourth photo here shows that it is less obvious when dried.

I still think the crust is too thick - in fact so thick it is spanning the cracks in the rock - and I can't see any obvious perithecia. The very flat black patches towards the top left and bottom left of pic 1 contrast strongly in thickness and are more like what I'd expect.

I would hate to mislead you, so I'm not being very decisive! Let's hope someone else can be.


Ginny B's picture

That Icelandic site photo

That Icelandic site photo does look nearer my first two photos and even that photo (from with the penny looks a bit nearer, but none of the other photos on that page.

I managed to go to the same rocks this morning and so I am adding today's photo, which has the edge of some calipers at the top of the pic to indicate size. (I have great difficulty in seeing what I'm photographing in bright sunlight such as we have today - sorry the calipers don't show that well.) Today's photo looks a lot more like it could be L.confinis but even with a hand lense I can't see much detail. It just looks like rather solid black chunks.


synan's picture

I was only really questioning

I was only really questioning the thickness, not the horizontal span, but I'm loving the callipers! Very usefully, they do show that the 'areoles' (island-like fragments) are up to 2-3mm in diameter, which further rules out H. maura (up to 600μm = 0.6mm).

I have discovered a forgotten sample of L. confinis, now thoroughly dried, and the structure isn't at all obvious except under a x20 hand lens. Today's close-up shows some fraying (branches?) at the edges.

All things considered, I think there is a reasonable case for dry L. confinis (it looks very different when wet, so not all photos are comparable). I would revise the ID, but it doesn't apply to pic 3.

I will post what I think is H. maura later.


AlanS's picture

I agree

This is L. confinis in dry state. My photograph with the penny is indeed the comparable photograph on my site. Your photograph shows more extensive patches, but that isn't a problem.


Ginny B's picture

Thank you, Alan.

Thank you, Alan. It is good to know what it is for sure. It's certainly taken me long enough to learn what to look for!! I was surprised that even in my two pictures taken on different dates that it looked as different as it did.

Ginny B's picture

Getting the thickness

Getting the thickness actually measured would be tricky!

I have removed picture 3 and will post it separately once I've had a closer look at your post and compared that with what I see on the rocks. Perhaps you would be kind enough to revise my original ID now that pic 3 is gone?

Thank you so much for all your help. It has really helped me appreciate what the differences are between these two black lichens.


synan's picture

If you do revisit (yet again!)...

... to look at Hydropunctaria, look for the perithecia (wart-like fruiting bodies) and cracks in the thallus. If your camera has a macro setting (or lens), you'll need it to capture them. I was trying to shade out strong sunlight, and my photo isn't the clearest, but you can just make out the openings (ostioles) in the tops of the perithecia, through which spores are released. Sites like Alan's and Jenny's have better photos under Verrucaria maura.

I'm off to do some lichenising in the Lake District so there will be less waffling from me for a few days!


Ginny B's picture

Thanks again Nigel.

Thanks again Nigel. Have a great time in the Lake District.