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 Stypella dubia
SynonymsSebacina pruinosa
Heterochaetella pruinosa
Heterochaete dubia
BiostatusPresent in region - Indigenous. Non endemic
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Caption: Sebacina pruinosa: c, paraphysoids; d, basidia; e, spores; f, thick-walled cystidia. |
Article: McNabb, R.F.R. (1969). New Zealand Tremellales - III. New Zealand Journal of Botany 7(3): 241-261 (http://www.rsnz.org/publish/abstracts.php).
Description: Fructifications waxy-mucilaginous, resupinate,
thin, effused, indeterminate, forming irregular areas to 6 cm longest dimension,
pruinose, hyaline when fresh, drying to an almost invisible, white or pallid
greyish white film; margins concolorous, adnate. In section to 50 µm thick excluding cystidia, consisting of basal
layer and hymenium. Basal layer poorly defined, thin, composed of indistinct,
interwoven, hyaline hyphae lying parallel with substratum, clamp; connections
present. Hymenium composed of cystidia, paraphysoids and basidia, dikaryophyses,
absent; cystidia straight or flexuous, grouped in fascicles, 75-150 x 4-5µm,
projecting 50-100 µm beyond basidia, thick-walled with narrow lumina basally,
thinner walled apically, smooth, tinted yellowish-brown; paraphysoids abundant,
rarely projecting beyond basidia, cylindrical to subclavate, often flexuous,
hyaline, thin-walled, contents hyaline, 19.5-29 x 4-5.4 µm; probasidia at first
subclavate to clavate later globose to broadly obovate, 7.2-10.5 x 6.5-7.8 µm
becoming longitudinally cruciate-septate; sterigmata subulate, to 10 µm long.
Basidiospores oblong-cylindrical, sometimes ovate and flattened on one side,
hyaline, inconspicuously apiculate, smooth, 5.8-7.5 x 3.2-4.1 µm. Germination
by repetition.
Habitat: Dead angiosperm wood.
Notes: The thick-walled, erumpent cystidia indicate
that this species belongs in Sect. Heterochaetella. Luck-Alien (1960)
accorded Heterochaetella full generic rank and recognised three species
in the genus. Of these, Sebacina pruinosa appears to be most closely
related to S. dubia (Bourd. & Galz.) Bourd. and Heterochaetella
bispora Luck-Allen. It may be distinguished from Sebacina dubia
by the presence of paraphysoids and absence of stellate, spinose, or irregularly
shaped crystals. From Heterochaetella bispora it differs in the presence
of 4-celled basidia and constantly fasciculate cystidia, and the absence of
branched dikaryophyses. As explained in an earlier publication (McNabb, 1966),
the conservative approach to the taxonomy of Sebacina (sensu lato) adopted
in this series of papers is occasioned by the present of agreement on the limits
of some generic segregates of this large and artificial genus. This approach
has been adopted mainly for convenience and does not imply rejection of the
studies of Luck-Alien (1960, 1963) and Wells (1959; 1961). On the contrary,
they make it clear that further genera will be recognised with in Sebacina
in the near future, but taxonomic readjustments in a group as complex as this
are outside the scope of a series of publications dealing exclusively with a
regional flora. However, efforts have been made to indicate the position of
new species in the generic segregates currently accepted by Luck-Allen and Wells.
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