Fleshy Fungi of New Brunswick >> Rhodocollybia prolixa var. distorta

Rhodocollybia prolixa var. distorta (Fr.) Antonín, Halling & Noordeloos

Clustered (2) among mosses in rocky area, aasociated with Betula cordifolia and Abies balsamea, Little Lepreau, New Brunswick (27-09-20/01).

Pileus broadly convex, with a low rounded umbo, dry, glabrous, pale orange to apricot (HSV25:20:90-100), 26-37 mm in diameter. Stipe equal, longitudinally ribbed, very plae orange to nearly white, dry, glabrous, 30-50 x 3-5 mm. Lamellae white, close to crowded, adnexed, eroded at the margins, not marginate. Flesh white, with a pronounced but rather nondescript odour and taste.

Basidiospores white in spore print, subglobose, smooth, often lightly dextrinoid in Melzer’s Solution, 3.5-4.5 x 3.1-3.8 μm, Q = 1.04-1.33 (average[37]: 3.9 x 3.4 μm, Q = 1.14). Cheilocystidia difficult to distinguish from immature basidia, clavate to ventricose, 23-32 x 4.2-6.5 μm. Pileipellis a cutis of hyaline clamped hyphae, with a subpellis of parallel radially encrusted brown hyphae. Pileus trama loosely interwoven. Basidia 4-spored, clamped at the base, 23-28 x 5.2-6.4 μm.

Rhodocollybia prolixa var. distortais not a highly charismatic mushroom and might easily be confused for a species of Gymnopus or Tricholoma. One clue to where it might be classified is with the stipe, which is longitudinally striate. The lamellae are irregularly eroded at the edges in a manner similar to those of Rhodocollybia lentinoides. Microscopically it can be distinguished by its subglobose, irregularly dextrinoid basidiospores and small nondescript cheilocystidia. It seems to be a rather infrequent mushroom in North America, but it may be simply overlooked by most collectors.

Collection 27-09-20/01 is not a perfect fit for Rhodocollybia prolixa var. distorta. It differs from descriptions by Antonín, Halling & Noordeloos (Libri Botanici 17. 1997) and Halling (https://www.nybg.org/bsci/res/col/rhodo.html) in having smaller basidiospores and in its habitat in coastal coniferous forest.

Photograph: D. Malloch (27-09-20/01).