E-Flora BC: Electronic Atlas of the Flora of British Columbia

Botryobasidium obtusisporum J. Erikss.
no common name
Botryobasidiaceae

Species account author: Ian Gibson.
Extracted from Matchmaker: Mushrooms of the Pacific Northwest.

Introduction to the Macrofungi

© Adolf Ceska  Email the photographer   (Photo ID #23380)

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Distribution of Botryobasidium obtusisporum
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Species Information

Summary:
Features include 1) resupinate growth on wood, 2) fruitbodies that are thin, loosely attached, cobwebby-cottony, and grayish white, 3) spores that are elliptic with the apex blunt-rounded, smooth, and inamyloid, 4) 6-spored basidia, 5) a monomitic hyphal system, the basal hyphae wide and thick-walled, the other hyphae more thin-walled, and 6) the absence of clamp connections.

James Ginns collected this species from Vancouver Island in BC (J. Ginns, pers. comm.). It has also been recorded from NC and TN (Ginns(5)) and Scandinavia (Eriksson). The distribution includes Europe and Asia (Breitenbach).
Fruiting body:
thin, at first hypochnoid [with dry rather loosely intertwined hyphae arranged flat on substrate], then more confluent; "greyish white or with age yellowish to pale ochraceous and of a loosely interwoven texture", (Eriksson), resupinate, forming thin patches several centimeters to decimeters in extent, loosely attached, membranous arachnoid-cottony, consistency soft and cottony; gray-white when moist, white to cream when dry; surface open and porous, (Breitenbach)
Microscopic:
SPORES 7.5-12 x 3.5-5 microns, obliquely oval, apex obtuse, smooth; BASIDIA (4-)6-spored, 17-25 x 8-10 microns, "at first rounded, then obovate to subcylindrical, somewhat constricted"; HYPHAE monomitic, BASAL HYPHAE 7.5-10 microns wide, yellowish, more or less thick-walled, with sparse branching, without clamp connections, hymenial branches 5-6 microns wide, colorless, more thin-walled, without clamp connections, (Eriksson), SPORES 8-11 x 3.5-4.5 microns, elliptic, obtuse apically, smooth, inamyloid, colorless; BASIDIA 6-(7-)spored, 12-15 x 8-9 microns, cylindric to clavate, without basal clamp connection; CYSTIDIA not seen; HYPHAE monomitic: BASAL HYPHAE 6-9 microns wide, yellowish, thick-walled, somewhat branched, without clamp connections, other hyphae about the same width, thin-walled, without clamp connections, (Breitenbach)

Habitat / Range

on conifer wood, rarely on hardwood, (Eriksson), on dead wood of conifers, according to literature more rarely on wood of hardwoods; spring-fall, (Breitenbach)

Synonyms and Alternate Names

Hypoxylon mediterraneum (De Not.) J.H. Mill.
Sphaeria mediterranea De Not.

Taxonomic and Nomenclatural Links

Additional Range and Status Information Links

Additional Photo Sources

Related Databases

Species References

Eriksson(2), Breitenbach(2)*, Ginns(5)

References for the fungi

General References