VIRTUAL MYCOTA: NZ Fungi Identification: Exidiopsis grisea

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Exidiopsis grisea

Synonyms

Sebacina umbrina
Exidiopsis umbrina
Thelephora grisea

Biostatus

Present in region - Indigenous. Non endemic

Images (click to enlarge)


Owner: J.A. Cooper	Owner: J.A. Cooper	Owner: J.A. Cooper	Caption: scale=2mm Owner: J.A. Cooper
Caption: basidia and spore Owner: J.A. Cooper	Owner: J.A. Cooper	Owner: J.A. Cooper	Owner: J.A. Cooper
Caption: Sebacina umbrina: a, basidia; b, paraphysoid; c, spores; d, dikaryophysis

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 soft-gelatinous to waxy-gelatinous, resupinate, thin, effused, indeterminate, forming areas to 10 cm in longest dimension, pruinose, dull ochraceous brown when fresh, drying to a similarly coloured vernicose crust; margins concolorous or slightly paler, adnate. In section 150-250 µm thick, consisting of basal layer and hymenium, ascending layer present in older fructifications. Basal layer thin, composed of indistinct, agglutinated, hyaline hyphae lying parallel with substratum, clamp connections present. Ascending layer when present composed of distinct, loosely interwoven, clamped hyphae of irregular diameter. Hymenium composed of dikaryophyses, paraphysoids and basidia: dikaryophyses variable in shape, ranging from cylindrical or narrowly subclavate to finely and irregularly branched apically, projecting to 25 µm beyond basidia; paraphysoids cylindrical, subclavate or clavate, often irregular or strangulated, arising from fertile hyphae or hyphae bearing dikaryophyses, hyaline, thin-walled, contents hyaline, non-granular, 35-62 x 4.5-9 µm, probasidia initially clavate, later ovate to obovate, often short-stalked, proliferating through conspicuous basal clamp connections, 13.6-17.4 x 8.7-11 µm, becoming 2-celled by longitudinal septa or longitudinally cruciate-septate; sterigmata cylindrical, to 40 µm long. Basidiospores curved-cylindrical to allantoid, hyaline, apiculate, 11-15.5 x 4-4.7-(5.2) µm. Germination by repetition.
Habitat: Dead angiosperm wood.
Notes: New Zealand specimens agree closely with North American and European descriptions of Sebacina umbrina. The cylindrical to clavate paraphysoids in S. umbrina have been variously interpreted. Both Rogers (1935) and McGuire (1941) regarded them as gloeocystidia homologous with those found in section Bourdotia, and included the species in subg. Bourdotia and sect. Bourdotia respectively. On the other hand, Wells (1957) considered that these structures differed from the gloeocystidia of Bourdotia and regarded them as paraphysoids, as did Luck-Alien (1963). Wells (1961) later termed them subcylindrical dikaryophyses. In New Zealand specimens, dikaryophyses are extremely variable in shape and in some instances closely resemble paraphysoids in size and shape, except for their irregularly branched apices.
Sebacina umbrina has usually been considered an autonomous species but recently Wells (1961) included it within his greatly expanded concept of Exidiopsis grisea (Pers.) Bourd. & Maire. In his treatment of E. grisea Wells reduced a number of European and North American species to synonymy. Oberwinkler (1963) and Donk (1966) both rejected this concept of E. grisea and regarded most of the European species as distinct. Luck-Alien (1963) remarked that she would place Sebacina umbrina in Exidiopsis subg. Bourdotia.