Observation 154069: Suillus kaibabensis Thiers

In irrigated grass under introduced aleppo pine (Pinus halepensis); approximately 30 individuals in circle at drip line. Cap up to 8 cm., pallid with bright yellow tinges and red patches at margin, kid leather feel when dry, sticky when wet. Pores large, angular, yellow brown. Tubes yellow brown and up to 1 cm. Stem 4 cm. × 2 cm., curved, tapering and reddish at base, pallid with sparse elongated reddish dots. Flesh of cap and stem firm and yellow white. Mild but odd odor. Pleasant taste to cap flesh but cuticle is tart. Cap surface and flesh of cap and stem reddish with ammonia. Cap surface and flesh of cap and stem black with KOH. Spore deposit cinnamon brown. Last rains a week ago. Elevation 3200’, temps 60’s day/ 35-40’s night.

PS I now think this is S. kaibabensis due to dots on stem and no partial veil (according to NA Boletes by BRB no dots on stem of S. occidentalis and it has a partial veil) and red stains on stem base. Association with something other than ponderosa pine is apparently not documented, but ponderosa and aleppo pines are both 2 needle pines. Mild odor and lack of veil on this obs would rule at S. pungens which has been associated with introduced aleppo pine in California but has a pungent odor and a partial veil.

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Reddish with Ammonia on cap surface
Black with KOH on cap surface
Ammonia reddish on flesh; KOH black on flesh
associated tree—introduced aleppos pine—2 needle
cinnamon brown spore deposit

Proposed Names

29% (1)
Recognized by sight
-62% (2)
Recognized by sight: Based on macroscopic features and reagent reactions this looks like S. sibiricus but I could find no reference to its association with 2 needle pine like the allepo. PS This obs is not red staining in the way of S. sibiricus and more importantly lacks a partial veil (see obs 246772). Also, S. sibiricus seems to be mycorrhizal with 5 needle (white) pines.
Used references: Kuo, M. (2007, December). Suillus sibiricus. Retrieved from the MushroomExpert.Com Web site: http://www.mushroomexpert.com/suillus_sibiricus.html
Based on chemical features: see above
-1% (2)
Recognized by sight: Just a guess as I have never seen this species.
75% (3)
Eye3 Eyes3
Recognized by sight: This is a fairly common species in the Four Corners area under Pinus ponderosa. We see it every summer by my grandfather’s old cabin in Groom Creek, outside Prescott, at about 6500 feet.
Based on chemical features: KOH/ammonia colors look just like Kuo’s reference and distinguish it from S. granulatus.

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Eye3 = Observer’s choice
Eyes3 = Current consensus


Add Comment
ITS: (569 of 572 match with KX213768 no gaps and 2 ambiguous bases)
By: Terri Clements/Donna Fulton (pinonbistro)
2017-04-05 20:59:49 BST (+0100)


Thanks, Walt
By: Terri Clements/Donna Fulton (pinonbistro)
2013-12-03 16:36:47 GMT (+0000)

I’ve done some research since your proposal and S. occidentalis has been recorded from Az in association with ponderosa pine, a 2-3 needle pine like the aleppo pine. In fact it seems to be reasonably common according to a recent article in Mycologia ( www.mycologia.org/content/102/2/438.full ) which discusses it in relation to a new species (S. quiescens) described from California and Oregon. Both the description by Thiers and the online photo from Dr. Scott Bates of ASU make the ID of S. occidentalis promising I think.


Alan or Walt
By: Terri Clements/Donna Fulton (pinonbistro)
2013-12-03 05:41:26 GMT (+0000)

Would you mind looking at this? S. sibiricus seems a fit except for the association here with 2 needle pine rather than 5 needle.



Created: 2013-12-03 03:07:51 GMT (+0000)
Last modified: 2017-04-05 20:58:08 BST (+0100)
Viewed: 184 times, last viewed: 2018-09-18 19:38:16 BST (+0100)
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