Full name: Hebeloma palustre Peck (1899)
Published: Ann. Rep. N.Y. St. Mus. 52: 649 (1899)
Taxonomic status: Heterotypic synonym of H. discomorbidum
Types: UNITED STATES: New York: Kasoag (approx. 43.46°N, 75.92°W, alt. approx. 190 m a.s.l.) on boggy, mossy soil in bog, Oct. 1898, C.H. Peck (Lectotype. herbarium acc. no. NYS-F-002244.1, HJB1000088). Lectotype designated by Eberhardt et al., Mycologia 114 (2): (2022) page 362 (MBT10000878).

Diagnosis: Pileus fleshy but thin, broadly convex becoming nearly plane with age, sometimes wavy or irregular, glabrous, hygrophanous, grayish brown and slightly striatulate on the margin when moist, paler when dry, flesh whitish; lamellae close thin ventricose, adnexed, grayish white becoming cinnamon brown; stem, rather long, equal or tapering upward, hollow, silky, white; spores subelliptic, uninucleate, .0004 to .0005 in. long, .00024 to .0003 broad [10.2-12.7 x 6.1-7.6 µm]. Pileus 1 to 1.5 in. broad [25.4-38.1 mm]; stem 2 to 3 in. long [50.1-76.2 mm], 2 to 4 lines thick [5.1-10.2 mm]. Mossy ground in swampy woods. Kasoag. October. The pileus is not viscid and there is no evidence of a veil.

Commentary: Hebeloma palustre belongs to H. sect. Hebeloma given the ventricose to lageniform cheilocystidia together with the amygdaloid and limoniform spores. Given the habitat, it is most likely in the group of species that includes H. clavulipes, H. hygrophilum, H. monticola and H. nigellum. The protologue mentions that the lamellae are close and from the exsiccata it would appear to be between 44 and 48, although estimating from the exsiccata is never without risk; this would rule out H. hygrophilum and H. nigellum, which normally never have more than 36 full-length lamellae. The spores, while a little short for H. clavulipes, could correspond to either H. clavulipes or H. monticola, but the number of lamellae would fit better with H. clavulipes. While we were unable to generate any sequences from the material, that might confirm this identification, we are confident that this is a correct identification. Note that H. discomorbidum, another species described by Peck, is conspecific. The name H. palustre has priority over both H. clavulipes and H. discomorbidum as well as over numerous other names, the majority of which were published by Smith et al. (1983). Twenty of the types of taxa published by Smith, synonymized with H. palustre above, were collected in Pitkin county, Colorado, between the years (1976) 1978–1980. It should be noted that we did not receive any type material for H. fragrans var. intermedium because of the sparsity of the material. Instead, we examined a topotype collected on the same day. Among the many heterotypic synonyms of H. palustre we now also include H. oreophilum. This latter taxon was originally described from the Western Carpathian Mountains in Slovakia. In Beker et al. (2016) it was pointed out that this species was both morphologically and molecularly closely related to H. clavulipes but could be separated on both habitat and its wider spores. Its description was based on 13 collections, while that of H. clavulipes was based on 21 collections. Since that publication we have had the opportunity to study many more collections of both taxa, including many collections from North America. We must conclude that this is a single species with a continuum of average spore width from 6–7.5 µm, and a range of habitats from lowland to arctic/alpine. This is similar to species such as Hebeloma dunense (but see H. velatum below), H. mesophaeum and H. nigellum which, as discussed in Beker et al. (2016), also occur in a similar range of latitudes and altitudes. Beker et al. (2016) reported that H. clavulipes cannot molecularly be separated from H. oreophilum based on five loci. Both are here synonymized with H. palustre. Molecularly, and not only in terms of ITS, H. palustre is very similar to H. fuscatum, H. hygrophilum, and H. nigellum. Since publishing H. fuscatum in 2016, based on just five collections, more intraspecific ITS variation has been observed in H. fuscatum so that the delimitation by ITS data between these two species has become less straight forward. Since the publication of Eberhardt et al. (2022a), it has been brought to our attention by J-P. Chaumeton that according to ICBN Art. 11.4 (Turland et al. 2018) the valid name for the taxon Hebeloma palustre is actually H. discomorbidum, as this species was originally described in 1873 as Agaricus discomorbidus, which predates the publication of H. palustre which was published in 1899. Hence this is: = Hebeloma discomorbidum (Peck) Peck.

Full name: Hebeloma palustre Peck, in House, (1915)
Published: Bull. N.Y. St. Mus.: 20 (1915)
Taxonomic status: This is a Pholiota.
Notes: Nom. illegit. (Art. 53.1 - Melbourne), non Hebeloma palustre Peck 1899. Name replaced by Hebeloma peckii House. Current name is: Pholiota peckii (House) Beker & U. Eberh.

Types: UNITED STATES: New York: Oneida County, Remsen (approx. 43.32°N, 75.19°W, alt. approx. 380 m a.s.l.) on boggy soil in woodland edge, 5 Aug. 1911, C.H. Peck (Holotype. herbarium acc. no. NYS-F-002245, HJB1000089).

Diagnosis: Pileus thin, convex, glabrous, viscid, yellowish or buff, sometimes tinged with red in the center; flesh whitish; lamellae plane, slightly sinuate, minutely crenulate on the edge, close, brownish ferruginous; stem equal, hollow, silky, pruinose at the top, whitish; spores brownish -ferruginous. Pileus 1.5-2.5 cm broad; stem 2-4 cm long, 1-2 mm thick. Gregarious or subcespitose. Wet places in the margin of woods. Remsen, Oneida county, August 5, 1911. C. H. Peck. The viscidity of the pileus is very tenacious.

Commentary: See Hebeloma peckii House.