Observation 81243: Elaphomyces Nees

When: 2011-10-29

Collection location: Yosemite National Park, California, USA [Click for map]

37.0° 119.0°

Who: Tom Bruns (pogon)

No specimen available

Found at the base of a Russula fruitbody.

site 4,
Yosemite National Park, Tuolumne Co, CA USA
along Glacier Pt Road, Sentinel Creek,
Lodgepole pine forest, on boarder of meadow.
N37 42.389 W119 35.339
7590 ft.

Species Lists


Sorry for this crumby photo.
closeup of thick two-layered peridium, the inner layer is white and homogenius;
not like the peridium described for E. muricatus
Spores vary from 19.6-33.4. Small for E. granulatus.

Proposed Names

90% (2)
Eye3 Eyes3
Recognized by sight: very hard thick perdium, black warty spores
Based on microscopic features: spores 19.9- 33 um, more or less round, warty
84% (1)
Recognized by sight: The two large “groups” of Elaphomyces are easily separated in the field by the presence or absence of spore clusters in the peridium. This does not have spore masses in the peridium, ergo it belongs to the Elaphomyces granulatus group.

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Eye3 = Observer’s choice
Eyes3 = Current consensus


Add Comment
Microscopy indecisive.
By: Daniel B. Wheeler (Tuberale)
2012-06-27 18:26:54 CDT (-0500)

According to Field Guide to North American Truffles, by Trappe, Evans, and Trappe, the spores of E. granulatus should be 24 to 60 microns, globose, with spines sometimes aggregating into warts. Spores should be black. These spores appear reddish to my eye. E. muricatus OTOH should have spores 18-35 microns in size, globose, also with spines sometimes aggregated into warts. Spores should be dark brown to reddish-brown.

Alexander H. Smith once called Elaphomyces the most ubiquitous hypogeous fungus in the Northern Hemisphere, and I see no reason to doubt him. It was one of the first species I found, under Oregon White oak at my parents farm near Lebanon, Oregon.

There are now known to be a number of other Elaphomyces world-wide, with variations not easily told by mere photos. One species novum I collected in the Columbia River Gorge area is distinctive for having a combination of red and green spores under 100x: a virtual color blindness chart of spores! To my knowledge that collection has not been assigned even a tentative name to date. While Elaphomyces are ubiquitous, keying them out to species is still a matter not easily undertaken. Apparently the genus is in need of revision.

Created: 2011-11-01 18:10:39 CST (-0600)
Last modified: 2013-12-03 12:24:43 CST (-0600)
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