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Page number:1170 
Remarks (internal):Morchella sextelata corresponds to phylogenetic species Mel-6 in O'Donnell et al. (2011). From a strictly morphological perspective the species is virtually identical to several members of the M. elata Clade (M. septimelata, M. brunnea, M. angusticeps, M. septentrionalis), but because it apparently is limited to conifer burn sites in western North America it can be easily separated from all but M. septimelata, from which it is morphologically and ecologically indistinguishable on the basis of currently available data. Elements on sterile ridges in the latter species were primarily subclavate to clavate in the specimens examined, while elements in M. sextelata were cylindrical with a rounded apex, subfusoid, subcapitate or block-like, but this distinction is too tentative and based on too few specimens examined for us to express confidence that the difference is consistent. Because several of the collections studied for the present work (F 07130403, F 07070405) had pinkish pits, M. sextelata probably was included in the concept of the “pink morel” set forth in Pilz et al. (2004, 2007); however, M. septimelata specimens also demonstrated pinkish pits. Morchella sextelata was treated in Kuo (2005) as one of several “Other North American Black Morels” appearing in burn sites. 
Description type:Original description 
Description:Morchella sextelata M. Kuo, sp. nov. Fig. 12
MycoBank MB 563955
Ascomata 40-105 mm high. Hymenophore 25-75 mm high; 20-50 mm wide at the widest point; conical to widely conical; pitted and ridged, with 12-20 primary vertical ridges and numerous shorter, secondary vertical ridges and sunken transecting horizontal ridges; attached to stipe with a sinus about 2-4 mm deep and 2-4 mm wide. Ridges glabrous or finely tomentose; pallid when young; becoming dark grayish brown to nearly black with maturity; bluntly flattened when young, sometimes becoming sharpened or eroded with age. Pits primarily vertically elongated; glabrous; dull brownish to yellowish tan, pinkish, or nearly buff. Stipe 20-50 mm high; 10-22 mm wide; more or less equal or sometimes basally subclavate; glabrous or finely mealy with whitish granules; whitish. Context whitish; 1-2 mm thick in the hollow hymenophore; sometimes slightly chambered near the base. Sterile inner surface whitish and pubescent. Ascospores 18-25 x 10-16(−22) µm; elliptical; smooth; contents homogeneous. Asci 200-325 x 5-25 µm; eight-spored; cylindrical; hyaline. Paraphyses 175-300 x 2-15 µm; cylindrical with rounded, subacute, subclavate or subfusoid apices; septate; hyaline in KOH (2%). Elements on sterile ridges 50-180 x 5-25 µm; septate; terminal cell cylindrical with a rounded apex, subfusoid, subcapitate or block-like; with brown to brownish contents in KOH (2%).
Ecology. Appearing at 1000-1500 m in lightly to moderately burned conifer forests, including forests dominated by Ps. menziesii and P. ponderosa. Found primarily in years immediately following forest fires but often appearing in dwindling numbers for several seasons thereafter; Washington, Idaho, Montana, Wyoming and Yukon Territory; April-July.
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