Hypogymnia physodes

Alternative names
Dark Crottle


Thallus foliose, lobes smooth and reflective above, flat to convex, hollow, pale to green-grey, dark brown to black beneath and lacking rhizines, tips often turned up and sorediate; apothecia rare, stalked, with red-brown discs.
Similar Species

Very variable and, when lobes are flat, can resemble Hypotrachyna laevigata, but the latter is larger and has repeatedly-branched rhizines beneath.

Identification difficulty
Recording advice

Unless identified by a recognised expert, a photo is required and the specimen should be examined with a microscope. In the comments box, state the key or ID method used and describe the size and identifying characters.


On acid-barked trees and heather (Calluna) stems, also terrestrial on base-poor dunes.

When to see it

All year round.

UK Status

Throughout Britain and often very common.

VC55 Status

Occasional in Leicestershire and Rutland.

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Leicestershire & Rutland Map


Yellow squares = NBN records (all known data)
Coloured circles = NatureSpot records: 2020+ | 2015-2019 | pre-2015

UK Map