Observation 92375: Calvatia pachyderma (Peck) Morgan

When: 2012-04-10

Collection location: Knowland Park, Oakland, California, USA [Click for map]

37.0° 122.0°

Who: Tom Bruns (pogon)

Specimen available

This fungus formed a huge (>50 m diameter) fairy ring in the meadow, which could be seen from the green zone it created in the grass. Fruiting was occurring primarily on one side of the ring, but also was starting on the other side. The largest individuals fruitbodies were maybe 15-20 cm across.

This could be C. booniana, and I have to confess that even after working through the key and descriptions I’m not sure I know the best distinctions. The scaly surface seems a little too scaly for the description of pachydermica, but the gleba color, the smooth spores, and the tiny pores in the capillitia made me lean toward pachyderma.

John Taylor was the one who originally found this cool fruiting.

Species Lists


large fairy ring is visible on opposite hill as a green zone in the grass
close up of fairy ring
spores in H20 – completely smooth other than the pedicel (about 4-6 um)
Spores in meltzers
capillitium in meltzers, the pores can be seen on the right hand side.

Proposed Names

83% (1)
Eye3 Eyes3
Used references: Fred Steven’s key
Based on microscopic features: Using Mykoweb’s descriptions the capilitium seems right.

Please login to propose your own names and vote on existing names.

Eye3 = Observer’s choice
Eyes3 = Current consensus


Add Comment
and an email from our local puffball expert
By: Tom Bruns (pogon)
2012-04-10 18:44:34 EDT (-0400)

I emailed Fred Stevens about this post and this is what he says:

Hi Tom-
That indeed is Calvatia pachyderma and that fairy ring is well known (at least among the few who collect puffballs) as the “Methuselah ring,” so called because its size indicates it could easily be a hundred years old. Of all the C. pachyderma fairy rings at the Knowland grassland, and there are quite a few, this one is by far the largest. It also fruits in the fall, and I’m a little surprised to see it fruiting now, perhaps confusion caused by the mid-winter dry spell? BTW, the scaliness is not unusual and varies depending on conditions. Hopefully the “Methuselah ring” will not be destroyed by the zoo’s expansion plans.


was it next to the…
By: Debbie Viess (amanitarita)
2012-04-10 16:30:30 EDT (-0400)

elephant enclosure? ;)

Created: 2012-04-10 16:20:25 EDT (-0400)
Last modified: 2012-04-10 18:46:34 EDT (-0400)
Viewed: 231 times, last viewed: 2017-11-29 01:39:59 EST (-0500)
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