Observation 217610: Leccinum sect. Leccinum

When: 2015-09-26

Collection location: Rush Oak Openings, Rush, New York, USA [Click for map]

42.9596° -77.682°

Who: I. G. Safonov (IGSafonov)

Specimen available

Three youngish basidicarps growing next to each other in a stand of young bigtooth aspen (Populus grandidentata) intermixed with a bit of black oak [tree ID by R. J. Cook of RAMA].
PILEUS: dark orange-brown (the flash in pix makes it more orange than brown) with a flap of sterile tissue [this feature places the specimens in Leccinum sect. Leccinum sensu Smith & Thiers]
CAP SURFACE: noticeably fibrillose (see pix)
PORE SURFACE: whitish, staining brown upon injury
STIPE: whitish with a dense cover of appressed blackish scabers
EXPOSED CONTEXT: staining grayish-violet, the color intensifying over time; NO preliminary reddish-cinnamon stage (typical of stirps Aurantiacum) was observed
CHEMICAL TEST: FeSO4 on context = greenish-blue, resolving pale blue

Molecular Data Discussion:
>A clean 1440 bp nrLSU sequence was obtained from this material.
>A GenBank BLAST search of the full-length sequence gave #AY612810, an American voucher of Leccinum aurantiacum (1014/1019 = 99.5% similarity), the only meaningful result.
>A GenBank BLAST search of the first 954 bases yielded a number of nearly perfect matches with several red/orange capped leccinum taxa. The two top hits are L. vulpinum #JN378516 (872/873 = ~100%), closely followed by the L. piceinum #DQ534614 (869/870 = ~100%). These two species are of European origin and grow under conifers; neither has been conclusively proven to occur in North America.
The full LSU sequence of this material didn’t match closely any leccinum sequences posted in GenBank because of a dearth of sequences of comparable length. A search of a sequence fragment led to many non-specific hits with a wide variety of scaber-stalk taxa with red or orange caps. Clearly the nrLSU gene doesn’t provide a sufficient resolution capacity below a certain sequence length and might not be able to provide it for full-length sequences either.

Species Lists


Cap texture is fibrillose
Taken ~1 minute following dissection
Taken ~7 minutes following dissection

Proposed Names

28% (1)
Used references: The Boletes of Michigan by Smith & Thiers
57% (1)
Eye3 Eyes3
Recognized by sight

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Eye3 = Observer’s choice
Eyes3 = Current consensus


Add Comment
DNA discussion posted
By: I. G. Safonov (IGSafonov)
2016-01-17 07:18:52 GMT (+0000)

Created: 2015-10-03 22:33:35 BST (+0100)
Last modified: 2017-11-06 03:12:04 GMT (+0000)
Viewed: 88 times, last viewed: 2018-04-17 19:41:00 BST (+0100)
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