Gymnopus confluens subsp. campanulatus (Peck) R.H. Petersen, 2015

Hughes, Karen W. & Petersen, Ronald H., 2015, Transatlantic disjunction in fleshy fungi III: Gymnopus confluens, MycoKeys 9, pp. 37-63 : 54-55

Gymnopus confluens subsp. campanulatus (Peck) R.H. Petersen comb. et stat. nov.

Basionym : Collybia confluens var. campanulatus Peck. “1901” (1902). Bull. N.Y. State Mus. 54: 963.

Type material.

Holotype. United States, New York, Bolton, IX.1900, coll. C.H. Peck (NYS). Epitype. CANADA, New Brunswick, Fundy Nat. Park, vic. Alma, Caribou Plains Trail, 45°38.587' N, 65°06.937' W, 25.IX.2013, coll Stephen Clayden, TFB14409 (TENN-F-69073)

Taxon diagnosis.

1) ITS nrDNA sequence significantly different from sequence of Gymnopus confluens subsp. confluens ; 2) basidiomata densely gregarious to subcespitose; 3) basidiomata apparently persistent beyond spore production and discharge; 4) stipe:pileus diameter ration from 2-5:1 (stipe significantly longer than pileus diameter); 5) pileus hygrophanous, brown where moist, pallid tan to pinkish buff where dry, drying to more uniform pallid color; 6) lamellae very crowded (total lamellae at pileus margin 110-140), shallow, seceding upon drying; 7) lamellar edge entire (smooth) to delicately fimbriate; 8) stipe grooved or compressed, stiff, with brown cortex (rind); 9) stipe vesture concolorous with pileus when moist and fresh, easily bleaching on drying to pallid gray shades; 10) basidiospores generally elongate-ellipsoid to sublacrymiform; 11) cheilocystidia stalked, usually lobed or strangulate, sometimes branched; 12) pileipellis hyphae smooth, firm-walled, with occasional to common side branches appearing digitate to long and branched. 13) Distribution in North America.

Description.

Gymnopus confluens subsp. campanulatus; taxon description:

Pileus: Pileus 7-33 mm broad, thin (parchment-like and brittle when dry), often generally truncate-conical to shallowly convex with downturned margin when young becoming applanate to somewhat flaccid campanulate by maturity, occasionally with very shallow umbo or flattened over disc, minutely suede-like (not glabrous); disc "cinnamon buff" (6B4; dry), "sayal brown" (6C5) to "tawny olive" (5C5; moist); limb and margin "pinkish buff" (6A3) to "tilleul buff" (7B2) occasionally in hygrophanous zones; margin entire to somewhat lobate, sometimes subtly closely striate when dry. Lamellae: Lamellae very crowded, free to adnexed but significantly seceding upon drying and leaving a pale, off-white ring around the stipe apex, with relatively numerous lamellulae, very shallow (1 mm or less deep), slightly thickish, "tilleul buff" (7B2), "light buff" (3A2) to "deep olive buff" (3C3); lamellar edge never totally smooth, minutely fimbriate to minutely serrulate and usually paler than lamellar face. Stipe: Stipe of mature basidiomata 35-80(-95) mm long, 2.5-4 mm broad, stiff, equal except for slightly expanded base and slightly flaring apex, consistently grooved or fluted (but not compressed), stuffed to profoundly hollow; cortex (rind) tough, russet to mahogany ("Mars brown" 8F7, "tawny olive" 5C5), glassy; medulla (interior), lightly stuffed, nearly hollow, grayish cream colored, loose; vesture more or less uniform over entire stipe length, consistently "tilleul buff" (7B2) to "pale olive buff" (3B2) when dry, detersile when fresh, easily disarticulated by handling when dry into minute chaff. Vesture of luxuriant form (New Brunswick, TFB 14409) delicately pruinose, apically concolorous with gills, soon "sayal brown"(6C5) to "Verona brown" (6E5). Odor none to faintly fresh; taste negligible to mild, perhaps weakly acidic, NOT acrid.

Habitat and phenology.

on duff under Quercus and other hardwoods including Acer (TENN 63806); gregarious on leaf litter under Fagus (TENN 47030) and occasionally Pinus ; hardwood duff (TENN 48376).

Pileipellis a thin layer of generally radially oriented hyphae; hyphae 4-11 μm diam, firm-walled, smooth (unornamented) to hardly ornamented (minute grit with suggestion of stripes or rings), conspicuously clamped, with infrequent, erect, side branches, ->75 μm long, 1.5-2.5 μm diam, simple to branched similar to cheilocystidial apices, arising from clamp connection or between clamps, often terminating in gradually tapering (2-4 μm diam at terminus) hyphal tips; contents heterogeneous, from amorphous sludge to coarsely spotted (PhC). Pileus and lamellar trama hyphae 3-9 μm diam, thin- to firm-walled, with occasional cheilocystidioid branches which seem to arise from clamp connections, conspicuously clamped, essentially free-form (TENN 53522), often anastomosing in “H” connections, when squashed often liberating minute debris in a subsoluble mucoid substance. Basidioles 22-25 × 5-7 μm, narrowly fusoid to torpedo-shaped, arising from a clamp. Basidia 21-30 × 7-9(-10) μm, clavate to broadly clavate, seldom bulbo-clavate, obscurely clamped, 4-sterigmate, arising from an obscure clamp; contents more or less homogeneous. Basidiospores (6-)6.5-9 × (2.5-)3-3.5(-4) μm (Q = 2.00-3.20; Qm = 2.59; Lm = 7.40 μm), elongate ellipsoid, somewhat flattened adaxially to slightly sway-back, thin-walled, smooth; contents homogeneous. In TFB 14409 (NB), spores plump ellipsoid to plump pip-shaped; contents 1-several guttulate. TFB 14389 (NB) produced somewhat smaller basidiospores [6-7 × (2.5-)3-3.5 μm (Q = 2.00-2.33(-2.80); Qm 2.16]. Lamellar edge entire to minutely fimbriate or minutely serrulate with cheilocystidia (64X), under magnification, lamellar edge fertile, with cheilocystidia locally abundant to sparsely scattered amongst fertile basidia; cheilocystidia typically (23-)34-77 × 2.5-4(-15) μm, hyphal, often 2-celled (with internal clamp), simple and substrangulate to usually branched with apical or subapical lobes or coralloid, contorted branches. Usually an accumulation of subsoluble mucoid material (with granular inclusions and embedded spores) surrounding cheilocystidial apices, perhaps exuded by the cheilocystidia themselves; cheilocystidia occasionally ramifying into slender (~1.5 μm diam), branched, arbuscular hyphal tips seemingly embedded in the mucoid matrix. Stipe surface hyphae 3.5-9 μm diam, strictly longitudinal and tightly parallel, occasionally but conspicuously clamped, often irregularly beset with small side lobes and short branchlets, sometimes arising from a clamp with a very thin mucoid sheath (with abundant embedded granular or globular material). Stipe vesture juxtaposed to stipe surface a thick, tightly interwoven thatch of thick-walled (wall -0.7 μm thick), very frequently branched, abundantly clamped hyphae 3.5-4.5 μm diam from which vesture columns and/or spikes arise; columns or spikes -100 μm tall, do not appear coherent, nor do they seem gathered from neighboring hyphae, but seem to arise in groups to form columns; caulocystidial hyphae -150 × 3.5-5 μm, thick-walled (wall -0.7 μm thick) at origin, soon branched (at a clamp) to produce two individuals, often with an additional internal clamp and further unbranched, firm-walled, conspicuously clamped, replete with numerous small lobes or branches, terminating in a bluntly rounded apex.