Geoglossum cookeanum
Anamorph: unknown.
Teleomorph: ascomata 30-70 x 5-15 (-20) mm, robust, irregularly shaped but usually roughly cylindric-clavate to clavate, more rarely spathulate or compressed, the apex obtuse to rounded, matt black (glossy when fully hydrated), not glutinous, ± smooth. Fertile part not clearly differentiated from the stipe, occupying the upper part of the ascoma and extending to around two thirds of its length. Stipe terete or slightly compressed, fuliginous to entirely black, initially furfuraceous and covered in short brown septate ± smooth-walled hairs, mostly falling away to leave a smooth surface at maturity. Interascal tissue composed of filiform paraphyses 2-3 µm diam., slightly longer than the asci and adherent in distinct clusters within a weakly developed dark brown gelatinous matrix, not curved or coiled at the apex, hyaline at the base, the upper part (roughly 20-25% of the length) pale to mid brown, more thick-walled and closely septate, strongly constricted at the septa and forming chains of ovoid to doliiform cells 4-6 µm diam., sometimes interspersed with narrow ± cylindrical cells, the apical cells sometimes reaching ca 8 µm diam. Asci 150-180 x 18-20 µm, cylindric-clavate to clavate, mostly slightly attenuated towards the rounded apex, fairly thick-walled but not fissitunicate, with a J+ apical pore, 8-spored. Ascospores arranged in parallel, (50-) 60-80 (-90) x 5-7 µm, narrowly cylindric-clavate with a rounded apex and acute base, straight or slightly curved, dark brown, 7-septate (rarely 6-septate), thick- and smooth-walled, without a gelatinous sheath or appendages.
Assessed as Near Threatened on a global scale by Minter & Cannon (2015), due primarily to population decline because of habitat degradation. Threats are considered primarily to be increased nitrogen levels due to agricultural "improvement", as well as fertilizer application in amenity grassland such as in churchyards. A similar assessment for the UK would be likely.
Characterized primairly by its robust non-gelatinized fruit bodies, paraphysis tips with chains of dark brown inflated ovoid to doliiform cells, and ascospores that are almost always 7-septate.
Throughout the entire British Isles, also widespread in Northern Ireland and ROI.
In acidic or basic grassland that has not been subject to fertilized application, also frequent in fixed and semi-fixed sand dunes.