Observation 217610: Leccinum A.H. Sm. & Thiers sect. Leccinum
When: 2015-09-26
(42.9596° -77.682° )

Notes: 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
> FeSO4 on context = greenish-blue, resolving pale blue

Molecular Data Discussion:
>A clean 1440 bp nrLSU sequence was obtained for this material
>A GenBank BLAST search of the full-length sequence did not produce a close match. The best hit in terms of identity match was a 1018 bp sequence from the Leccinum aurantiacum voucher HN1573, accession #AY612810 (99% identity with 2 gaps; 1014/1019 bp overlay, only 70% coverage).
>A GenBank BLAST search of a shorter fragment of my sequence (the first 971 bp) yielded several high-score hits with several red/orange capped leccinum taxa. The aforementioned L. aurantiacum voucher HN1573 was the top score hit (score = 1668 pts; 914/919 bp overlay, 94% coverage; 99% identity with 2 gaps).
> On the other hand, the two top highest identity hits belonged to the L. vulpinum voucher KPM-NC-001783, accession #JN378516 (score = 1607 pts; 872/873 bp overlay, 89% coverage; 99+% identity with no gaps), closely followed by the L. piceinum strain Lp1, accession #DQ534614 (score = 1602 pts; 869/870 bp overlay, 89% coverage; 99+% identity with no gaps). The latter two species are of European origin and occur under conifers, while L. aurantiacum is also a European taxon that is found under a variety of broadleaf trees. None have been conclusively proven to occur in North America.

Conclusion:
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.

Images

560766
560770
Cap texture is fibrillose
560771
560772
560773
Taken ~1 minute following dissection
560774
Taken ~7 minutes following dissection

Proposed Names

28% (1)
Used references: The Boletes of Michigan by Smith & Thiers

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Eye3 = Observer’s choice
Eyes3 = Current consensus

Comments

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DNA discussion posted
By: I. G. Safonov (IGSafonov)
2016-01-16 23:18:52 PST (-0800)

Created: 2015-10-03 14:33:35 PDT (-0700)
Last modified: 2016-03-19 17:09:59 PDT (-0700)
Viewed: 48 times, last viewed: 2016-11-04 18:58:28 PDT (-0700)
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