Arcyria helvetica (Meyl.) H. Neubert, Nowotny & K. Baumann

Sporocarps (only 4) in a small group along grass straw, stipitate, ± globose to obpyriform, total height ca. 1.3 mm, sporotheca diam. ca. 0.8 mm, brownish red with copper reflections.

short, ca. o.3 mm high, thin, clearly delimited from calyculus, dark reddish brown by RL.

brownish, confluent under sporocarps.

thin, pale brownish red by TL, persistant for some time and then flaking away in small pieces, ± shining.


of 3-4 µm broad tubules, only fixed at center of calyculus, hardly expanding, medium dense to dense netted, almost smooth towards base, with gradually more prominent ornamentation towards apex, in apical part with rings, halfrings and smaller and less well defined elements, some logitudinally interconnecting lines, ornamentation may be rather high, up to 2-3 µm, occasionally spiny.

Spores bright dark rose coloured by RL, almost hyaline to faintly greyish yellow by TL, mostly globose to somewhat irregularly shaped, 6.5 - 6.84 - 7.5 µm Ø, by 1000x apparently very delicately warted with scattered small groups of more prominent warts.

On grass straw in mixed Calluna-grass heath. Grazed by horses.

Distribution in Denmark
Rare. Known from one find: Jyll., Biowide 001 Råbjerg Kirke, 04-10-2015, On grass straw in dune. Leg. Annegrete Eriksen & Thomas Læssøe

Global distribution
Reported from scattered localities in Europe and Asia, mainly from alpine or subalpine areas.

Arcyria helvetica is generally considered a species of cooler climates, temperate to subarctic, in central Europe often in the mountains. The Danish locality is near sea level, but in close connection with the dunes along the North Sea. In Denmark such areas are well known for finds of subalpine species, such as Sarcoletia globosa and Multiclavula vernalis.

Description based on the only, very scarce, Danish collection: SA_TL2015-719192.


Abbreviations: TL : transmitted light; RL : reflected light; Ø : diameter; TBU : Danish Botanical Topographical District.

Colour-codes refer to: Kornerup, A. & J. H. Wanscher 1974: Farver i farver. 5th reprint. Politikens Forlag, Copenhagen.

When not otherwise indicated spore measurements are given as: min-mean-max or (extreme-)min-mean-max(-extreme). Spore measurements are exclusive of ornamentation.

Line drawings are free hand sketches.

Distribution maps: Maps of Danish distributions are based on material seen by the author. World distributions are based on reports extracted from literature.