Observation 99122: Pisolithus arhizus (Scop.) Rauschert
When: 2012-07-03
(37.8944° -122.2783° 137m)
No herbarium specimen

Notes: This was in a grassy planted strip between the street and the sidewalk. A dark liquidy substance came off on my fingers as I dug out the specimen. I didn’t note the type of tree nearby.

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Definately a pin oak.
By: Daniel B. Wheeler (Tuberale)
2012-07-06 01:28:52 CDT (-0400)

So-called because of the points or “pins” on the tips of the leaf lobes.

If the tree is native to CA, it could be Quercus kellogii (California Black oak). Apparently it hybridizes with other pin oaks as well. So this could also be a hybrid between Q. kellogii and, say, Q. palustris, aka Eastern Red pin oak. Q. palustris has been introduced extensively into the PNW and I suspect California as well. It grows rapidly here, possibly because of the extensive mycorrhizal fungi present. I have one growing in my backyard now. As well as an Oregon White oak (Q. garryana), which was planted by a friendly squirrel.

I am looking forward to seeing if I can grow native truffles with Q. garryana. Need to find some mature first.

The liquidy substance stayed on for a day or so, but I didn’t try washing it much.
By: Debbie Klein (dejaklein)
2012-07-05 22:44:06 CDT (-0400)

I think the tree was a form of red oak. I added pictures of it.

By: Daniel B. Wheeler (Tuberale)
2012-07-05 13:52:51 CDT (-0400)

in base of gleba proof enough for me.

BTW, Pisolithus forms mycorrhizae with so many tree species, giving a nearby host might be meaningless, anyway. Pinus, eucalyptus, Quercus, birch, walnut, cherry. Not sure about sagebrush, but wouldn’t be surprised to learn it was there too.

Regarding the dark liquidy substance: has it remained on your fingers after several washings? Dye-maker’s puffball strikes again!

Created: 2012-07-04 00:47:35 CDT (-0400)
Last modified: 2012-07-05 13:48:55 CDT (-0400)
Viewed: 60 times, last viewed: 2016-10-27 18:16:38 CDT (-0400)
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