Collema tenax Collemataceae
Collema tenax sens lat.

Chemical results: Negative

Very variable. Collema tenax var. tenax is the most frequent of three morphs on mortar in walls and on basic soils, sand and clay.
Dark green-black thallus (swollen when wet), crowded lobes and red-brown apothecia with smooth margins. Isidia usually absent but large when present and can appear lobe-like. Asci usually 8-spored, spores 3-septate to muriform, 17-26 x 6.5-10.5 Ám. Micro photograph below.

Similar: C. tenax var. vulgare is usually very fertile with plumper lobes. Collema tenax var. ceranoides is rarely fertile with ascending lobes,

C. bachmanianum has warted, crenulate margins, spores 26-36 x 10-15 Ám


Collema tenax


Collema tenax


Collema tenax

Microscope photograph
Collema tenax
Collema tenax
Godlingston Hill and Dancing Ledge, the Purbecks, Dorset. October 2012 and February 2013

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