Entoloma lycopersicum

Karstedt, Fernanda, Bergemann, Sarah E., Gates, Genevieve, Ratkowsky, David, Cunha, Kelmer Martins & Capelari, Marina, 2024, Species of Entoloma (Entolomataceae) with cuboidal basidiospores from Brazil, Phytotaxa 654 (1), pp. 1-76 : 46-48

Entoloma lycopersicum E. Horak & Singer, Sydowia 35: 78. 1982.

Figs. 20 , 27e–g , 37f–g

Description:— Pileus 10–25 mm diam., parabolic when young, becoming applanate, translucent-striate, apricot orange with the center of the pileus the same color as the striations, hygrophanous, surface smooth, pileus margin striate and sometimes whitened in relation to the rest of the pileus. Pileus context thin. Lamellae adnexed, adnexed-sinuate or sinuate, faces smooth, ventricose, apricot orange, distant with one or two tiers of lamellulae, margins entire or slightly irregular. Stipe 10–25 × 1–3 mm, cylindrical, centrally attached or slightly eccentric, apricot orange, slightly translucent, silky, glabrous, smooth, hollow, with white basal tomentum. Stipe context apricot orange. Odor and taste not observed. Spore print not observed.

Basidiospores cuboidal, sometimes with slightly protruding angles, 4-angled in profile view, excluding the projections 8–10(–11.2) × 8.7–10(–11.2) µm [xm = 9.7 (± 0.83) × 9.1 (± 0.73) µm, Q = 1–1.16, Qm = 1.07 (± 0.07), n = 50/3], including the projections 8.7–11.2 × 8.7–11.2 µm [xm = 10.1 (± 0.57) × 10.5 (± 0.64) µm, Q = 1–1.14, Qm = 1.04 (± 0.06), n = 50/3] and diagonally 11.2–13.7 × 11.2–13.7 µm ([xm = 12.3 (± 0.7) × 12.3 (± 0.7) µm, Q = 1–1.1, Qm = 1.02 (± 0.04), n = 50/3], thin-walled. Basidia clavate, 45–63 × 13.7–16.2 µm (n = 31/2), hyaline, thin-walled, 4-sterigmate. Cheilocystidia abundant, along the entire lamellar margin, cylindrical, cylindro-clavate, clavate or napiform, sometimes irregular, hyphoid or with apex subcapitate, 40–113 × 5–18.75 µm (n = 30/2), hyaline or with some straw yellow intracellular pigment, thin-walled. Pleurocystidia and pseudocystidia absent. Lamellar trama formed by parallel, cylindrical or sometimes inflated hyphae, 6.2–21 µm diam. (n = 46/3), hyaline, thin-walled, septa distant, sub-hymenium branched. Pileitrama composed of radially arranged hyphae, 5–29 µm diam. (n = 35/3), cylindrical, cylindro-clavate or irregular, hyaline or sometimes with some brown intracellular pigment, thin-walled, septa distant. Pileipellis a cutis formed by a few slightly entangled and prostrate hyphae, 5–10 µm diam. (n = 41/3), straw yellow or hyaline, thin-walled, septa distant. Stipitipellis a cutis, hyphae cylindrical, 3.7–10 µm diam. (n = 20), hyaline or straw-yellow, thin-walled, septa distant. Caulocystidia absent. Clamp connections present. Refractive hyphae present.

Habitat:—Solitary or slightly gregarious, on wood or, occasionally, in sandy soil with litter, in the Amazon Forest biome.

Distribution:—Originally described from material collected in the state of Amazonas ( Horak 1982) and now reported, for the second time to science, from the state of Pará.

Additional material examined:— BRAZIL. Amazonas: Manaus, Reserva Florestal Adolfo Ducke , 28 June 1978, E.M.L. Freire & R. Singer B11248 (Holotype, INPA; isotype, ZTMyc 4345, formerly ZT 80/158); Manaus-Caracaraí (km 45), 11 July 1977, R. Singer B10066 ( INPA); 25 June 1980, R. Singer B12125 ( INPA); R. Singer B 12148 ( INPA); Pará: Caxiuanã, Caxiuanã National Forest , Plot 3, 5 March 2007, R. Maziero TBGAG151 ( MG), 18 February 2008, R. Maziero TBGAG590 ( MG) .

Comments:—The collections of Rolf Singer B 11248 (Holotype, INPA), B12125 (Paratype, INPA) and B12148 (Paratype, INPA) are in poor condition. The holotype consists of a small basidiome with a pileus measuring 5 mm diameter, hard and brittle and with adhering sand; collection B12148 is composed of a small basidiome, with a pileus measuring 7 mm diameter, also hard and brittle. Under microscopy, all structures remained collapsed, including the basidiospores. Collection B 12125, on the other hand, consists only of the stipe and thus, it was not possible to confirm the identification.

The isotype (ZTMyc 4345, formerly ZT 80/158) of Entoloma lycopersicum is composed of a whole basidiome with a thin, reddish brown membranous pileus, translucent-striate, 9 mm diam., decurrent, distant lamellae and one or two tiers of lamellulae with a slightly darker color than the pileus, and a centrally attached, thin, collapsed, slightly fibrous 25 mm long stipe with a little yellowish white basal tomentum. Microscopic analysis was included in the species description. However, it was not possible to visualize the cheilocystidia, because the margin of the lamellae was damaged and in the few regions where it appeared to be sterile with cheilocystidia present it was not possible to separate them from the margin to make any measurements.

Entoloma lycopersicum can be recognized by the orange to red basidiome with a strongly striate pileus, the cuboidal basidiospores with angles that are at most only slightly elongated, cheilocystidia that vary from cylindrical to clavate or slightly irregular and obvious clamps. In the field, it can be easily confused with a Mycena or a Hygrocybe , mainly due to its vibrant color, its translucent-striate and glabrous pileal surface, and lamellae that are concolorous with the pileus.

Species with orange or red basidiomes are rare in Entolomataceae , with Entoloma haematinum Manim., Leelav. & Noordeloos (2002:625) , described from Kerala ( India), being the species that most resembles E. lycopersicum . Both have small basidiomes, a translucent-striate, glabrous pileus, in addition to cuboidal basidiospores and were collected in litter. However, E. haematinum has decurrent lamellae, smaller basidiospores (6.5–8.5 × 6–8 µm) that lack elongated angles, a fertile lamella margin without cheilocystidia, clavate pileocystidia and caulocystidia, and an absence of clamps (Manimohan et al. 2002) which differentiates it from E. lycopersicum . The recently described Entoloma coccineum T.H. Li, J.H. Xing & X.S. He (2021:107) from China can be compared to E. lycopersicum but that species has brilliant red rather than orange basidiomes and the lamellae are deeply decurrent.

An attempt to obtain DNA sequences of this species was made but was unsuccessful.

Figures

FIGURE 20. Entoloma lycopersicum: a–c. basidiospores: a. ZTMyc 4345; b. TBGAG590; c. TBGAG151; d. basidia (TBGAG590); e. cheilocystidia (TBGAG590); f. pileipellis (TBGAG151). Scales: a–e: 10 µm, f: 20 µm.

FIGURE 27. Microphotography of basidiospores in electron microscopy: a–d. Entoloma luteobrunneum (FK1693). e–g. E. lycopersicum (TBGAG151); h–j. E. manausense (FK2083); k–n. E. neotropicale (FK2130); o–q. E smurfetti (FK1717). Scale: 5 µm.

FIGURE 37. Basidiomas: a. Entoloma caribaeum (FK1790); b–c. E. dragorufescens: b. FK2102; c. FK2116; d–e. E. dragoluteum (FK2131); f–g. E. lycopersicum: f. TBGAG151; g. TBGAG590. Photos: a–e: F. Karstedt; f–g: R. Maziero. Scale: 1 cm.