Fleshy Fungi of New Brunswick >> Gymnopus cf. ocior

Gymnopus cf. ocior (Pers.) Antonín & Noordel.

Three collections:

• 1. Gregarious in bark and woody litter under a large dead Acer saccharum in mixed woods, Grand lake Meadows Protected Natural Area, New Brunswick (13-06-13/02).

  • Basidiospores white in spore print, dacryoid, smooth, inamyloid, 4.5-5.8 X 2.4-3.5 μm Q = 1.54-2.04 (average[13]: 4.9 X 2.9 μm, Q = 1.73). Basidia 4-spored, clamped at the base. Cheilocystidia clavate to cylindrical to lobed or branched. Pileipellis a dryophila-structure, unencrusted, lacking rameales elements.

• 2. Gregarious (5) on a rotting conifer log with bark still attached, Spednic Lake Protected Natural Area, New Brunswick (21-08-17/06).

  • Basidiospores white in spore print, dacryoid, smooth, without iodine reactions, 3.9-5.2 X 2.2-2.9 μm, Q = 1.53-2.04 (average[35]: 4.5 X 2.6 μm, Q = 1.75). Cheilocystidia cylindrical and rather hypha-like, branched. Pileipellis a dryophila structure.

• 3. Gregarious (many) on a decaying log of Betula papyrifera in forest dominated by Acer saccharum, Betula papyrifera and Fagus gradifolia. Kennedy Lakes Protected Natural Area, New Brunswick (01-07-19]01).

  • Basidiospores white in spore print, dacryoid, smooth, not amyloid or dextrinoid, 5.0-6.2 x 2.6-3.2 μm, Q = 1.67-2.13 (average[32]: 5.5 X 3.0 μm, Q = 1.84). Cheilocystidia abundant, variously branched or lobed, less commonly clavate and unbranched. Pileipellis a thin interwoven hyphal matrix bearing numerous branched and lobed terminal cells (a “dryophila structure”), seen most clearly in surface view rather than cross section. Basidia 4-spored, clamped at the base.

Gymnopus ocior is generally regarded as a European species not occurring in North America. It is closely related to the common G. dryophilus and differs from it in having a darker and non-striate pileus, a pale stipe and less lobed or coralloid cheilocystidia. Distinguishing these taxa in North America, if they even occur there, is difficult. As presented here, the name G.cf. ocior is applied to collections with a relatively dark pileus growing mainly on wood. The stipe is usually slightly to conspicuously swollen at base. There may be slight differences in the cheilocystidia, with those of G.cf. ocior being more filamentous, but these distinctions are difficult to resolve. The collections presented here are very similar to ones identified as G. cf. striatipes, and have in common very small basidiospore averaging less than 5.0 μm in length. They differ mainly in the less fasciculate growth habit and narrower basidiospores of G. cf. ocior. Use of the term "cf." in the names of our collections comes from the Latin conferatur, compare, and simply indicates that our collections should be compared to those species as conceived by other authors.

Photo: D. Malloch (13-06-13/02, 21-08-17/06, 01-07-19/01).