Marasmius jalapensis Murrill (1915: 264)

Ramírez, Natalia A., Niveiro, Nicolás, Salvador-Montoya, Carlos A., Motta, Fátima Piris Da, Pérez, M. Laura & Popoff, Orlando F., 2021, Marasmius tricystidiatus sp. nov. (Agaricales, Marasmiaceae) and its morphological and phylogenetic relationship with Marasmius jalapensis, Phytotaxa 494 (1), pp. 59-74 : 67-71

Marasmius jalapensis Murrill (1915: 264) . Figs. 5 , 6B–C , 7C–D

MycoBank: MB200160

Description:— Basidiomata marasmioid. Pileus to 40 mm diam., plano-convex to subumbonate, smooth, margin entire, striate, greyish orange in the center (5B3–B4), with brownish orange (5C4–C5) umbo, pale yellow (4A3) to yellowish white (4A2) towards the margin; surface glabrous, dry, dull, papyraceous to subvelutinous. Context thin, less than 1 mm, membranous, yellowish white (4A2); odor and taste not noted. Lamellae adnexed to free, subventricose, close, L= 38–44, regular, l= 2–3 tiers, with brown setae visible under hand lens, pale yellow (4A3); margin entire, concolorous. Stipe 40–55 × 0.5–1 mm, central, cylindrical, equal, cartilaginous, hollow; surface dull, pruinose to finely pubescent under hand lens, pubescence denser at the apex, dark brown (7F5) to light brown (7D1), paler towards the apex until it becomes concolorous with the margin of the pileus; strigose basal mycelium, yellowish white (4A1–A2). Spore print whitish (4A1).

Basidiospores 7.5–11 × 3–5.5 µm, x = 9.2 × 4.2; Q= 1.8–3; Q x = 2.2; n= 20; N=2; lacrymoid to subcylindric, smooth, hyaline, thin-walled, inamyloid. Basidia 28–36 × 6–7 µm, clavate, smooth, hyaline, 4-spored, thin-walled, inamyloid. Pleurosetae 50–144 × 10–21 µm, lanceolate, smooth, with acute apex, rarely acuminate, thick-walled (2.5–5 µm thick), chestnut brown, abundant. Cheilosetae 27–80 × 7–14 µm, similar to pleurosetae, lanceolate, smooth, thick-walled (1–3.5 µm), with acute apex, very abundant. Hymenophoral trama strongly dextrinoid, subregular, formed by hyaline hyphae, cylindrical, smooth. Pileipellis hymeniform, composed of thick-walled Siccus - type broom cells, main body 16–42.5 × 4.5–13.5 µm, with apical setulae up to 9 µm long, thick-walled (1–2.5 µm), golden melleous, intermixed with thin-walled Siccus - type broom cells, main body 21–21.5 × 7.5–9 µm, hyaline, inamyloid, abundant. Pileosetae 21–66 × 3–11 µm, acicular, simple, smooth, scattered among broom cells of the pileipellis, with acute apex, thick-walled (0.5–1.5 µm). Stipitipellis made up of elongated hyphae, up to 7.5 µm diam, parallel, cylindrical. Caulosetae 10–105 × 2.5–13 µm, simple, similar to pleurosetae but smaller, sometimes with widened base and acute apex, thick-walled (0.5–2.5 µm), golden melleous to brown, more abundant in the apex of the stipe, less numerous towards the base. Clamp connections present.

Ecology and distribution:—marasmioid, on leaf litter, in forest with predominance of Rapanea lorentziana ( Mez 1902: 394) Arechavaleta (1909: 42) . Mexico ( Murrill 1915; Guzmán 1983), Bolivia ( Singer 1976), Colombia ( GBIF 2020), and Paraguay. This is the first record for Paraguay and represents the southernmost limit of the species.

Specimens studied:— BOLIVIA. Beni: Vaca Diez, Ivon , on rotten wood, 3 April 1956, R. Singer B2470 ( LIL!) . MEXICO. Veracruz: Jalapa , 12–20 December 1909, W.A. Murrill & E.L. Murrill 84 (Type NY 00774651 !) . Ibid. W.A. Murrill & E.L. Murrill 169 ( NY 00774652 !) . Ibid. Parque Ecológico El Haya, Bosque mesófilo de montaña, 1300 m asl., 14 March 2001, C. Cuevas-Suárez 428 ( XAL!) . Ibid. 31 March 2001, C. Cuevas-Suárez 497 ( XAL!) . Ibid. 28 September 2001, C. Cuevas-Suárez 598 ( XAL!) . Ibid. 7 January 2002, C. Cuevas-Suárez 627, 629, 632 ( XAL!) . Ibid. SO de Banderilla, Cerro La Martinica , Bosque mesófilo de montaña, 1550 m asl., 10 January 1985, V.M. Bandala- Muñoz 7 ( XAL!) . PARAGUAY. Paraguarí: Compañía Mbatoví , 25°34’12.9’’S; 057°5’50.17’’W, 13 May 2017, F. Piris da Motta 414F ( CTES!) .

Additional specimens studied:— TRINIDAD and TOBAGO. Trinidad : Forest, Siparia Quarry, 8 April 1921, F.J. Seaver 3497 ( NY 02506197 !) . UGANDA. Buganda : Mpanga Reserve Forest, solitary on fallen debris, 1241 m asl., 8 June 1968, Pegler 1327 ( K 134432 !) ; Ibid., N. of Entebbe , Zika Forest, on leaf litter, 1189 m asl., 12 June 1968, Pegler 1448 ( K 116823 !) .

Comments:— Marasmius jalapensis is characterized by its medium-sized basidiomata, the coloring of the pileus with greyish orange to yellowish white tones, crowded lamellae, and the presence of setoid cystidia in all tissues. The examined samples correspond to the species as described by Singer (1976), differing only by having slightly smaller basidiospores (7–9 × 2.5–3.5 µm) and slightly smaller pleurosetae (44–110 × 7–17.5 µm).

The most similar species is M. tricystidiatus (described above) and its similarities and morphological differences were discussed previously. Many features of M. jalapensis match those reported for M. coarctatus from Thailand ( Wannathes et al. 2009), such as the shape and colouring of the pileus, composition of the pileipellis, presence of hymenial cystidia and caulosetae, but the latter forms basidiomes with fewer lamellae (33–36), smaller basidiospores on average (6.6 ± 0.4 × 3.0 ± 0.2 μm), and cheilo-and caulocystidia in form of Siccus - type broom cells. Other morphologically similar species that resemble M. jalapensis are M. nummularius , M. diversus and M. coklatus . The former, M. nummularius , differs in forming darker and smaller pileus (6–20 mm diam.), subdistant lamellae (L=12–18, l=1–2 tiers), longer basidiospores (12–14 μm), the presence of cheilocystidia and rare pleurocystidia in the form of Siccus - type broom cells, and by the absence of setae in the hymenium ( Wannathes et al. 2009). The second species, M. diversus , is distinguished by its darker pileus, less numerous and more distant lamellae (L=24–35), shorter stipe (30–38 mm), longer basidiospores (14–16 μm), cheilo-and caulocystidia in the form of Siccus - type broom cells, pleurocystidia which are cylindrical to substrangulate, and by the absence of pleuro-and cheilosetae ( Grace et al. 2019). The third, M. coklatus , differs in having a dark brown pileus (6F4–6; 9–10F5–8), distant lamellae (L=10–15, l= 1 tier), cheilo-and pleurocystidia in the form of broom cells, and smaller pleurosetae (25–51 × 3–5 µm) ( Desjardin et al. 2000; Wannathes et al. 20009).

Pegler (1977) and Antonín (2007) described some African specimens as M. jalapensis . We analyzed in detail two specimens from Uganda (K 134432, K 116823) and concluded that they differ from the type material by having narrow and crowded lamellae, smaller basidiospores (5.5–8 × 2.3–3.5 µm) ( Fig. 6D ), and two types of cheilocystidia, viz., Siccus - type broom cells and setae ( Figs. 7E–F ). The African specimens do not belong to M. jalapensis in the current concept, but due to the characteristics mentioned above, they could be M. aff. delectans . Furthermore, all collections deposited in the NY herbarium under the name of M. jalapensis were morphologically analyzed. One of them, collected in Trinidad and Tobago (NY 02506197), shows morphological differences to the type material of M. jalapensis such as longer basidiospores (14–16 × 4–5 µm) and the absence of thick-walled setoid cystidia in the hymenium and pileipellis. This last specimen may be M. aff. rubricosus Montagne (1854:110) due to the dark brown pileus and size of basidiospores (15–18 × 4–5.5 µm) ( Singer 1976). However, we did not observe cheilocystidia in the form of broom cells, or other features that are typically lost in dried specimens. Therefore, the identity of this NY herbarium specimen (NY 02506197) cannot be confirmed.

Figures

FIGURE 5. Macroscopic and microscopic features of Marasmius jalapensis (414F). A. General aspect and habit. B. Basidiospores. C. Pleurosetae. D. Cheilosetae. E. Thick-walled Siccus-type broom cells of pileipellis. F. Pileosetae. G. Caulosetae. Scale bars A = 10 mm, B–G = 10 µm. Photographs by F. Piris da Motta; drawings by N.A. Ramírez.

FIGURE 6. SEM micrographs of basidiospores. A. Marasmius tricystidiatus (NR 100). B. Marasmius jalapensis (414F). C. Marasmius jalapensis (type material, Murrill & Murrill 84). D. Uganda specimen (K 134432). Scale bars = 2 µm. Photos by N.A. Ramírez.

FIGURE 7. SEM micrographs of cheilocystidia. A–B. Marasmius tricystidiatus (NR 100). C. Marasmius jalapensis (type material, Murrill & Murrill 84). D. Marasmius jalapensis (414F). E–F. Uganda specimen (K 134432). Scale bars A–B = 5 µm, C–F = 10 µm. Photos by N.A. Ramírez.