Termitomyces medius Heim et Grassé

Mossebo, D. C., Essouman, E. P. F., Machouart, M. C. & Gueidan, C., 2017, Phylogenetic relationships, taxonomic revision and new taxa of Termitomyces (Lyophyllaceae, Basidiomycota) inferred from combined nLSU- and mtSSU-rDNA sequences, Phytotaxa 321 (1), pp. 71-102 : 89-93

Termitomyces medius Heim et Grassé ( Figs. 11A /B/C/D & Fig. 12A )

Synomymy: Termitomyces striatus f. grisumboides Mossebo , Bulletin de la Société Mycologique de France 118(3): 214–217 & 247 (2002).

Pileus 20–60 mm diam. at maturity, rarely exceeding 60 mm, initially campanulate to subhemispherical, becoming convex to plano-convex and later applanate, rarely recurved; yellowish to brownish grey (4B2-6D2), most often rimose at various lengths from the margins and showing an obtuse, ± conspicuous greyish brown (6D3) perforatorium highly contrasting with the yellowish to brownish grey (4B2-6D2) pileus surface. Lamellae whitish, ± straight, 2–6 mm wide, free with regular edge, crowded with lamellulae of different lengths. Stipe 30–80 × 3–9 mm, solid, brownish grey (4B2-6D2) to greyish brown (6D3), subcylindric, swelling towards the base to a diameter ≤ 14 mm and abruptly tapering to form a 20–100 mm long underground pseudorhiza. Annulus absent. Context whitish, ≤ 4 mm thick at the junction with the stipe. Spore-print whitish. Odour odorless.

base of the stipe

A B C D E F G

1 T. striatus (Beeli) obtuse to Yes, Thin-walled Thin-walled, Thick-walled, Thick- Gelatinized R. Heim obtusely ( Heim, 1977) ( Heim, 1977) 4 sterig-mata, ( Heim,1977) walled, epicutis made conical and Pegler ( Heim 1977) (Heim, of parallel non ( Heim, 1977) (1977) 1977) inflated hyphae 1-2.5 μm diam ( Pegler, 1977)

A B C D E F G

2 T. striatus f. mammiform, No , but Thick-walled Thin- (Fig. Thin-walled Thin-walled Made of bibasidiatus conspicuous with a long ( Fig. 8A ) 8B) and thick- ( Fig. 8E ) ( Fig. 8D ) intermixed Mossebo ( Fig. 7A ) pseudorhiza walled (Fig. globular to

( Fig. 7A ) 8C) ovoid cell ( Mossebo et al., 2002)

A B C D E F G

3 T. striatus f. obtuse to Yes/No, ± Thin-and Thin-walled, Thin-walled Absent (Fig. Repent subclypeatus acute or conspicuous, thick-walled 2 and 4 ( Fig. 6C ) 6) structures

D.C. Mossebo & spiniform, ± with a shorter ( Fig. 6A ) strerigmata made of an E.P.F. Essouman conspicuous pseudorhiza ( Fig. 6B ) alternation of, ( Figs. 7B / subcylindrical, C/D) short cells and larger ovoid to globose cells ( Mossebo et al., 2002)

A B C D E F G

4 T. medius Heim Present, Most often Thick- and Thin-walled, Thick- and Thick- and Made of et Grassé triangular conspi- thin-walled of 2 (rounded thin- walled thin-walled intermixed to obtuse, ± cuously ( Fig. 11A ) tips) and 4 ( Fig. 11D ) ( Fig. 11C ) repent and conspicuous, present (pointed tips) erected hyphae dark grey to [Fig. 41(3) sterigmata ( Heim, 1977) grey blackish in Heim ( Fig. 11B ) or ± parallel ( Fig. 12A , (1977) and repent hyphae arrow) and Fig. 12A left], intermixed with Heim (1977) or absent (Fig. subglobose

12A right)] to ovoid cells ( Fig. 15C in Mossebo et al., 2002)

A B C D E F G

5 T. medius f. Absent or No, Only Thin- Thin-walled, Thin-walled Thin-walled Made of repent ochraceus D.C. inconspicuous conspicuously walled (Fig. of 2 and ( Fig. 13C ) ( Fig. 13D ) hyphae (Fig. Mossebo & as a barely absent ( Fig. 13A ) 4 uniform 13E)

E.P.F. Essouman visible 12 B/C) sterigmata pseudo-umbo ( Fig. 13B )

( Fig. 12B ,

arrow)

Basidiospores 5– 5.90 –6.7 × 3.8– 4.05 –4.7 μm, 1.25 ≤ Q ≤ 1.62, Q R = 1.48, hyaline, ellipsoid, some pip-shaped, rarely subglobose, thick- and thin-walled with granulous content, some with a single guttule. Basidia 13–20 × 6–7.5 μm, most often clavate, sometimes subcylindric, bearing 2 and 4 sterigmata, rounded at the tip in 2 spored basidia and rather pointed in the 4 spored ones. Pleurocystidia 17–26 × 8–16.5 μm, clavate, subutriform to widely fusiform, appendiculate, few in number compared to cheilocystidia. Cheilocystidia 14–34 × 6–16 μm abundant, clavate, rarely utriform to fusiform with some appendiculate elements as in pleurocystidia. Hymenophoral trama regular, consisting of unclamped hyphae, 3–7.5 μm diam. Lactiferous hyphae 5-12 μm diam., abundant in lamellae of some strains, absent or rare in others, inflated and/or sinuate-waved in some hyphal parts. Subhymenium pseudoparenchymatous, mixed up with ± rounded cells, 3–8 μm diam. Context consisting of branched and intermixed hyphae showing short cells, 2–7 μm diam. Pileipellis consisting of ± parallel repent hyphae intermixed with subglobose to ovoid cells, 5–15(–20) μm diam.

Habitat, ecology and growth: Grows mostly isolated, but sometimes in small groups, on grass, lawn and cultivated plantations around urban centers, mostly in the vicinity of subterranean termitarium during the short rainy season ranging from March and May.

Distribution: Found only in Cameroon.

Specimens examined: 1. Holotype: –– CAMEROON, Center region, Yaoundé (on a grass gulf pitch in “Mbankolo” neighborhood in the suburbs of Yaoundé), 15 May 2001, collected by Nzié Nkodo, HUY1-DM 372. 2. Isotypes: 2- 1.— CAMEROON, Center region, Yaoundé (in grass in the campus of the University of Yaoundé 1), 5 May 2008, collected by D.C. Mossebo and students, HUY1-DM 372B. 2-2.— CAMEROON, Yaoundé (in grass in the campus of the University of Yaoundé 1), 26 April 2014, collected by D.C. Mossebo and students, HUY1-DM 372G.

Termitomyces medius form ochraceus D.C. Mossebo & E.P.F. Essouman f. nov. ( Figs. 12B /C & Figs. 13A /B/C/D) MycoBank: MB819330

Diagnosis: Termitomyces medius form ochraceus f. nov is characterized by a more or less concolorous pileus and stipe, uniformly pale yellow, reddish to brownish grey or greyish to brownish orange, the pileus of relatively small size (20–40 mm diam) at maturity, and in addition to the concolorous pileus, the key distinctive feature is the absence or inconspicuous perforatorium in form of a pseudo-umbo more or less concolorous to the pileus, as well as a total absence of a thickening at the base of the stipe before the pseudorhiza. Pleuro- and cheilocystidia abundant and polymorphic.

Etymology: –– The epithet of this new form refers to its key distinctive feature which is the more or less concolorous, ochraceus color of the stipe and pileus which either lacks a perforatorium, or if present, it forms an inconspicuous pseudo-umbo.

Holotype: –– CAMEROON, Centre region , Yaoundé (in « Nkolban » village in the suburb of Yaoundé near the cow slaughter-house of “Etoudi” neighborhood), 15 September 2009, collected by students, HUY1- DM 602 B.

Pileus 20–40 mm diam. plano-convex to applanate, most often with a slight depression around the perforatorium in form of an obtuse, generally inconspicuous pseudo-umbo at the middle of the disc; surface smooth, uniformly pale yellow (4A3), reddish to brownish grey (6B2-6C2) or greyish to brownish orange (6B4-6C4), sometimes rimose at margins. Lamellae whitish, free, ≤ 3.5 mm wide at the junction with the stipe, somewhat wavy with regular edge, crowded with lamellulae of different lengths. Stipe 50–70 × 3–6 mm, uniformly pale yellow, reddish to brownish grey or greyish to brownish orange, subcylindric showing no swelling from top to the base, gradually tapering to form an underground pseudorhiza. Annulus absent. Context white, thin, 1–2 mm thick.

Basidiospores 3– 5.8 –7.5 × 3– 3.8 –5 μm, 1 ≤ Q ≤ 1.5, Q R = 1.4, hyaline, thin-walled, ellipsoid to subglobose with one or several guttules. Basidia 17–25 × 6–8 μm, hyaline, clavate to subcylindric, bearing 2 and 4 sterigmata, sometimes guttulate and/or granulous. Pleurocystidia 20–47 × 10–23 μm, clavate, thin-walled, widely clavate to piriform or widely lageniform to subutriform. Cheilocystidia 20–51 × 8–28 μm, thin-walled, polymorphic as pleurocystidia, widely clavate to subglobose, lageniform to subutriform and appendiculate with a pedicel ≥ 10 μm long. Hymenophoral trama subregular with hyphae, 4–10 μm diam. Subhymenium pseudoparenchymatous. Pileipellis regular, consisting of repent hyphae, 10–13 μm diam.

Habitat, ecology and growth: Grows isolated on grass and in cultivated plantations in the vicinity of subterranean termitarium during the great rainy season that ranges from September to mid-November in Cameroon.

Distribution: Only collected from Cameroon.

Specimens examined: Holotype: –– CAMEROON, Centre region , Yaoundé (in « Nkolban » village in the suburb of Yaoundé near the cow slaughter-house of “Etoudi” neighborhood), 15 September 2009, collected by students, HUY1- DM 602 B. Notes:–– Ref. Notes above on T. medius .

Figures

FIGURE 6. Termitomyces striatus form subclypeatus (KM 143 968 = HUY1-DM 370B, holotype and HUY1-DM 151, HUY1-DM 151C). A. Basidiospores. B. Basidia. C. Cheilocystidia. Scale bars: A-C = 10 μm.

FIGURE 7. A. Termitomyces striatus form bibasidiatus (HUY1-DM 280B) with a long underground pseudorhiza (Fig. 7A arrow). B/C/D Termitomyces striatus form subclypeatus [(KM 143 968 = HUY1-DM 370B with an acute to spiniform perforatorium (Fig. 7D arrow) and HUY1-DM 151 with a twisted stipe (Fig. 7B: arrow)].

FIGURE 8. Termitomyces striatus form bibasidiatus (HUY1-DM 280). A. Basidiospores. B. Thin-walled Basidia. C. Thick-walled Basidia (sclerobasidia). D. Pleurocystidia. E. Cheilocystidia. Scale bars: A-E = 10 μm.

FIGURE 11. Termitomyces medius (HUY1-DM 372G). A. Basidiospores. B. Basidia. C. Pleurocystidia (thin- and thick-walled). D. Cheilocystidia (thin- and thick-walled). Scale bars: A-B = 10 μm. C-D = 10 μm.

FIGURE 12. A. Termitomyces medius (HUY1-DM 372G, holotype): arrow shows the conspicuous perforatorium. B/C Termitomyces medius form ochraceus (HUY1-DM 602B, holotype): arrow shows the absent or inconspicuous perforatorium. Basidiomes B and C removed from ethanol (90°) conservation. Description was done on freshly collected basidiomes before dipping them in ethanol. D/E. T. brunneopileatus (KM 144 300 = HUY1-DM 392 and KM 144 301 = HUY1-DM 394, holotypes).

FIGURE 13. Termitomyces medius form ochraceus (HUY1-DM 602B, holotype). A. Basidiospores. B. Basidia. C. Cheilocystidia. D. Pleurocystidia. E. Pileipellis. Scale bars:A-D = 10 μm. E= 20 μm.