Stemonaria pilosa Nann.-Bremek.

Fructification
Sporocarps stipitate, cylindrical to "cigar-shaped", usually in small clusters of 2 to ca. 15, total height 5-7 mm, ca. 0.3 mm broad, dark greish brown.

Hypothallus
Thin, membranous, reddish brown and translucent, common to a group of sporocarps.

Stalk
Ca. 1/3 of total height, thin, shining black by RL, deep reddish brown to almost black opaque by TL, hollow - air bubbles ocasionally seen in water prep.

Peridium
Early evanescnet, not seen.

Columella
An extension of the stalk, gradually tapered, reaching almost to apex where it is typically flexuose, giving rise to columella along whole length, dark reddish brown to almost black by TL.

Capillitium
Primary branches moste ± orthogonal to columella, 1-2 µm broad, forming an internal net with 2-3 meshes, branches ocasionally flattened and often with triangular widenings at nodes, reddish brown by TL, thin peripheral branches often anastomosing but not forming a net, many ca 5-15 µm long, free, pointed branches at periphery.

Spores
Globose, pale greyish brown by TL, with small, short spines arranged in a mostly somewhat fragmentary net, ca. 5-7 meshes along a diameter, spines not connected with ridges and not forming a rim along periphery, 6 - 7.4 - 9 µm Ø (n=25, excl ornamentation).

Ecology
Most danish finds were developed in moist chamber on branches of Rubus fruticosa coll. A few were collected from rotten, deciduous wood.

Distribution in Denmark
Known from three localities in North-Zealand, and from two localities in east and central Jutland.

Global distribution
Reported from France, Germany and Sweden in Europe and from Mexico, Taiwan and New Caledonia. (Not all localities shown on map)

Discussion
The genus Stemonaria was erected in 1984 by Nannenga-Bremekamp, N. E. et al., separated from Stemonitis by the absence of a peripheral capillitial net. This character may be difficult use, as the net of weathered specimens of Stemonitis may be torn and fragmentary. A safe identification thus requires good material.

Stemonaria pilosa bears some resemblance to small specimens of Stemonitis fusca. In the field the notably smaller size and small and open clusters of sporocarps are often indicative. In the microscope a careful examination of the surface of the capillitium is neccesary.

The Danish material has been compared to documentation of three collections identified as S. pilosa or S. cf. pilosa and kindly sent by Marianne Meyer. The comparison did not give rise to changing the identification.

Description
Description and discussion based on three collections from moist chamber: hfg 2385, hfg 2713 and hfg 2810.

 


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.

Stemonaria pilosa:
Stemonaria pilosa Nann.-bremek. - Sporocarps
Sporocarps (hfg2809)
Stemonaria pilosa Nann.-bremek. - Sporocarps
Sporocarps (hfg2810)
Stemonaria pilosa Nann.-bremek. - Capillitium
Capillitium (hfg2385)
Stemonaria pilosa Nann.-bremek. - Sporocarps
Spores (hfg2385)