Fleshy Fungi of New Brunswick >> Tricholoma fulvum

Tricholoma fulvum (DC.) Bigeard & H. Guill.

Gregarious (8) in a Pleurozium schreiberi carpet with some Dicranum spp, associated with Abies balsamea and Picea mariana, Little Lepreau, New Brunswick (05-10-19/01).

Two collections:

• 1. Solitary among gametophytes of Pleurozium schreiberi and Rhytidiodelphus sp. in lawn, associated with Betula cordifolia and Abies balsamea, Little Lepreau, New Brunswick (05-10-20/02).

  • Pileus conic-turbinate at first, not seen when fully expanded, with a low broad umbo, glabrous, reddish brown (HSV05:50:40-50), slightly paler at the margin, appressed-fibrillose, moist, 30 mm in diameter. Stipe equal down to the slightly tapered base, dry, with reddish brown (HSV05:50-60:70) streaks over a pale yellow (HSV55:05-10:100) ground colour, hollow, 46 X 9 mm. Lamellae pale yellow (HSV55:03:100), close, adnexed, not marginate. Veil not seen, probably lacking. Flesh pale yellow (HSV55:05-10:90-100), with a strong farinaceous odour and taste.

    Basidiospores white in spore print, broadly ellipsoidal, smooth, inamyloid, with a large spherical inclusion in water, Windex and NH₄OH, 5.3-6.8 x 4.0-5.0 µm, Q = 1.25-1.53 (average[39]: 5.8 x 4.3 µm, Q = 1.35). Cheilocystidia lacking. Basidia clavate, 4-spored, without a basal clamp connection. Pileipellis a loosly interwoven cutis, composed of brown hyphae marked by conspicuous radial encrustations, without a conspicuous gelatinous matrix. Clamp connections lacking on all hyphae.

  2. Gregarious (3) in gravel at the margin of a driveway, associated with Abies balsamea and Larix laricina, Little Lepreau, New Brunswick (29-09-20/03).

  • Pileus convex, without an umbo, viscid, glabrous, dull reddish brown (HSV15:50-60:60), 58-60 mm in diameter. convex, without an umbo, viscid, glabrous, dull reddish brown (HSV15:50-60:60), 58-60 mm in diameter. convex, without an umbo, viscid, glabrous, dull reddish brown (HSV15:50-60:60), 58-60 mm in diameter. Stipe strongly ventricose, pointed at the base, glabrous, concolorous with with pileus, 25 X 22 mm. Lamellae pale yellow (HSV50:05:95), subclose to subdistant, adnexed, not marginate. Veil lacking. Flesh pale yellow (HSV50:05:100) in the pileus and upper half of the stipe, dark brown (HSV15:50:40-50) in the lower half of the stipe, with a farinaceous odour and taste.

    Basidiospores white in spore print, ellipsoidal, smooth, 5.5-7.2 x 4.1-4.8 µm, Q = 1.22-1.60 (average[39]: 6.0 x 4.4 µm, Q = 1.37). Cheilocystidia lacking although a few hyphal extensions of the lamellar trama may protrude between the marginal basidia. Pileipellis a loose cutis of brown finely encrusted hyphae, possibly gelatinous but this feature is not conspicuous, without clamp connections. Lamellar trama parallel, light brown, with hyphae finely encrusted. Basidia 4-spored, clavate, without a basal clamp connection.

Tricholoma fulvum, is recognized by its reddish brown viscid to subviscid pileus, lack of a veil, pale yellow lamellae and flesh, and strongly farinaceous odour and taste. Under the microscope its basidiospores are rather typical for the genus in being broadly ellipsoidal and with a large round globule when mounted in water, KOH, NH₄OH and Windex, but not in Melzer's Solution. The viscid pileus is probably due to gelatinous material in the pileipellis, although this is not apparent in microscopic sections. Instead the pileipellis is seen as a parallel to somewhat entangled mass of brown strongly encrusted hyphae that do not appear to have become gelatinized.

Collection 29-09-20/03 is unusual for the species in having a very short ventricose stipe. This feature is so marked, both in the young individual and the mature ones, that there is reason to suspect that it might belong in some other species. However, other than the stipe, it is typical of T. fulvum. Perhaps the driveway gravel influenced its growth.

Photograph: D. Malloch (05-10-20/02, 29-09-20/03).