Termitomyces striatus form subclypeatus D.C. Mossebo & E.P.F. Essouman f.

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 : 82-89

publication ID	https://doi.org/ 10.11646/phytotaxa.321.1.3
persistent identifier	https://treatment.plazi.org/id/BF5AED63-FFE0-BC09-FF7F-6C39707FF945
treatment provided by	Felipe
scientific name	Termitomyces striatus form subclypeatus D.C. Mossebo & E.P.F. Essouman f.
status	f.

Treatment

Termitomyces striatus form subclypeatus D.C. Mossebo & E.P.F. Essouman f. View in CoL nov. ( Figs. 6 View FIGURE 6 & 7 B View FIGURE 7 /C/D)

MycoBank: MB819326

Synonymy: Termitomyces subclypeatus D.C. Mossebo View in CoL , Bulletin de la Société Mycologique de France 118(3): 237–240 (2002). Termitomyces subclypeatus f. tetrasporus D.C. Mossebo View in CoL , Bulletin de la Société Mycologique de France 118(3): 237–240 (2002).

Diagnosis: Termitomyces striatus form subclypeatus f. nov. is characterized at macroscopical level, by its polymorphic perforatorium acute to spiniform, obtuse to obtusely conical or less conspicuous, however shorter than that of T. clypeatus ; a rimose pileus, greyish to beige in young specimens, turning brownish to brown when mature, with a diameter generally ranging between 10–70 mm, rarely exceeding 80 mm; a stipe 50–180 × 6–15 mm, sometimes showing a slight thickening on the median part with absence of annulus. The key distinguishing microscopical features are the clavate to subcylindrical basidia, bearing 2 or 4 sterigmata and the absence of pleurocystidia.

Etymology:–– The epithet of this new form refers to the morphology of its pileus of the striatus type and its acute to spiniform perforatorium, obtuse to obtusely conical in some strains, however shorter than that of T. clypeatus .

Holotype:–– CAMEROON, Western region , Mbouda (Mbamboutous division) about 420 km north-west of Yaoundé (capital of Cameroon), 18 April 2001, leg. D.C. Mossebo, collected by D.C. Mossebo, K(M) 143 968 (=HUY1- DM 370 B).

Pileus initially acutely conical, 10–35 mm diam., becoming obtusely conical and finally convex to plano-convex, rarely exceeding 80 mm diam. at maturity; color initially orange whitish to pale orange (6A2-6A3) in young specimens, more or less radially and deeply incised at various lengths showing the contrasting white context in some strains, slightly viscid when freshly collected or rather moist in others, turning greyish yellow (4B3) to brownish orange (6C4-6C5) when mature; perforatorium ± conspicuous, obtuse to obtusely conical or pointed conical to spiniform at maturity. Lamellae whitish, ≤ 6 mm wide at maturity, showing lamellulae of various lengths, free with regular edge, sometimes curved, straight or slightly ventricose, moderately crowded including lamellullae of various lengths. Stipe 50–180 × 6–15 mm, whitish, sometimes subcylindrical or twisted, but most often of irregular shape, showing a slight thickening on the median part in some specimens, gradually tapering towards the base to form an underground filiform pseudorhiza, 100– 300 mm long, solid and fibrous, sometimes bounded together in pairs attached to a single pileus. Annulus absent. Context whitish, ≤ 5 mm thick at the stipe junction. Spore print white to pale orange (6A2-6A3) or greyish to brownish orange (6B4-6C4). Odour odorless.

Basidiospores (4.9–)5.9 – 6.12 – 7 × (3–)3.9 – 4.52 – 5 μm, 1.2 ≤ Q ≤ 1.75, Q R = 1.43, hyaline, ellipsoid to subglobose, thin- and thickwalled, showing a granulous content and most often with a single guttule, inamyloid. Basidia 14–25 × 5–8.5 μm, clavate to subcylindrical with one or several guttules, some with a granulous content, bearing 2 or 4 sterigmata, most often showing a single or several guttules. Pleurocystidia absent. Cheilocystidia 13–26 × 7–18.5 μm, clavate to piriform, rarely subglobose, sometimes appendiculate with a ± long and septate pedicel bearing 1 to 3 septa. Hymenophoral trama subregular, consisting of unclamped hyphae, 4–12 μm diam. Subhymenium pseudoparenchymatous consisting of subglobose cells, 4–7 μm diam. Context consisting of branched, unclamped hyphae, 5–16 μm diam. showing relatively narrow cells or with constrictions at septa level. Pileipellis consisting of repent hyphae of various forms with relatively short cells, 4–6 μm diam., mixed with larger, subcylindrical, subglobose to ovoid cells ≤ 26 μm diam.

Habitat, ecology and growth: some strains grow isolate, other fasciculate or in large groups, found in Cameroon exclusively in the short rainy season (March, April, May) in the vicinity of giant and mostly subterranean termitarium in savannahs, open forestry areas and food-stuff plantations. Species of associated termites are not yet clearly identified.

Distribution: collected only from Cameroon where some strains ( Figs. 7C View FIGURE 7 /D) are common, growing on a yearly basis and others ( Fig. 7B View FIGURE 7 ) are rather rare.

Specimens examined: 1. Holotype:–– CAMEROON, Western region, Mbouda (Mbamboutous division) about 420 km north-west of Yaoundé (capital of Cameroon), 18 April 2001, collected by D.C. Mossebo, K(M) 143 968 (=HUY1- DM 370B). 2. Isotypes: 2-1.–– CAMEROON, Western region, Mbouda (Mbamboutous division) about 420 km north-west of Yaoundé (capital of Cameroon), 14 May 1998, collected by Tané, HUY1-DM 151. 2-2.–– CAMEROON, Western region, 23 May 2014, collected by. E.F.P. Essouman, HUY1-DM 370G.

Notes: ––With regards to Termitomyces striatus , the key differences ( Table 2) with T. striatus f. subclypeatus include the following:

1. The pleurocystidia, which are piriform, clavate or cylindric ( Pegler 1977) in T. striatus , whereas they are conspicuously absent in T. striatus f. subclypeatus ( Fig. 6 View FIGURE 6 ),

2. The thick-walled cheilocystidia in T. striatus ( Heim 1977) . They are rather thin-walled ( Fig. 6C View FIGURE 6 ) in T. striatus f. subclypeatus ,

3. The thick and thin-walled basidiospores in T. striatus f. subclypeatus ( Fig. 6A View FIGURE 6 ), whereas they are just thin-walled in T. striatus as described by various authors including Heim (1977) and Pegler (1977),

and accessorily also:

4. The thin-walled basidia bearing 2 and 4 sterigmata ( Fig. 6B View FIGURE 6 ) in T. striatus f. subclypeatus , they bear only 4 sterigmata as described by various authors including Heim (1977) and Pegler (1977).

Growth environmental factors and possible influence of other genetic factors may explain the morphological differences observed between several forms existing in T. striatus . These forms and varieties have been previously described in T. striatus by various authors, including Heim (1958) for T. striatus var. annulatus and T. striatus f. griseus, Heim (1977) for T. striatus f. annulatus and T. striatus f. substriatus, Mossebo et al. (2002) for T. striatus f. bibasidiatus , and Mossebo et al. (2011) for T. striatus f. camerunensis .

Some specimens of T. striatus f. subclypeatus show similarities with T. clypeatus as described by Heim (1958, 1977), Pegler & Vanhaecke (1994) and Van der Westhuizen & Eicker (1990), particularly with regards to some key characteristics of the stipe, the pileus and the perforatorium ( Fig. 7D View FIGURE 7 arrows), which is however much longer in T. clypeatus (said to reach 2/3 of the pileus diameter in some specimens of T. clypeatus ), pointed and much more pigmented than the pileus of T. striatus f. subclypeatus where the perforatorium is shorter and rather ± concolorous to the pileus. Both taxa however differ by some key microscopic features including mainly:

1. Pleurocystidia, which are absent in T. striatus f. subclypeatus , but present in T. clypeatus ,

2. The presence of 2 and 4 sterigmata, clavate and subcylindrical basidia in T. striatus f. subclypeatus , whereas these basidia only bear 4 sterigmata and are much more longer and larger in T. clypeatus (Pegler 1958, 1977; Van der Westhuizen & Eicker 1990; Pegler & Vanhaecke 1994),

3. The pileipellis of T. striatus f. subclypeatus is made of repent structures showing hyphal cells of various forms and size, some of which subglobose, ovoid to subcylindrical measuring up to 26 μm in diameter, whereas in T. clypeatus , the pileipellis is a cutis consisting of repent hyphae, measuring just 2.5–7 μm diam.,

4. The basidiospores thin- and thick-walled in T. striatus f. subclypeatus , they were just described as thin-walled in T. clypeatus by Pegler (1958, 1977), Pegler & Vanhaecke (1994) and Van der Westhuizen & Eicker (1990).

Termitomyces striatus form bibasidiatus D.C. Mossebo ( Fig. 7A View FIGURE 7 & Figs. 8A View FIGURE 8 /B/C/D/E), in Mossebo et al. Bulletin de la Société Mycologique de France 118(3): 207–211 (2002)

Etymology: ––This taxa was named based on the two types of basidia it displays, including thin- and thick-walled basidia, a quite peculiar feature in the genus Termitomyces .

Notes: ––The morphological characteristics of T. striatus f. bibasidiatus resemble T. striatus as described by various authors including Heim (1942, 1952, 1958, 1977), Pegler (1977), Van Der Westhuizen & Eicker (1990) and Buyck (1994). At macroscopical level, the main distinctive feature of this form of T. striatus as described by Mossebo et al. (2002) includes the cylindrical and sometimes spiral-like stipe without annulus and the relatively long pseudorhiza that could measure up to 600 mm long. However, the key distinctive features of T. striatus f. bibasidiatus is at the microscopic level, with the presence of two types of basidia ( Figs. 8B View FIGURE 8 /C), a quite peculiar feature in the genus Termitomyces . Other distinctive features include the structure of the pileipellis, which is made of ± globose to ovoid cells, as opposed to the most often rather filamentous and repent hyphae observed in this taxon. Finally, the spores which are ± thick-walled in T. striatus f. bibasidiatus , are usually described as thin-walled in T. striatus . This taxon falls in T. striatus subclade B3 ( Fig. 1 View FIGURE 1 ) strongly supported by a bootstrap value of 97% ( Fig. 1 View FIGURE 1 ). The macroscopic and microscopic descriptions of T. striatus form bibasidiatus initially described from the holotype ( Mossebo et al. 2002), are revised from the isotype as follows:

Pileus 70–100 mm diam, plano-convex to applanate, pale yellow (4A3) to reddish grey (6B2) or brownish orange (6C3-6C4 to 6C5) with a mammiform to obtusely conical perforatorium, most often rimose at the margins. Lamellae whitish, straight to slightly ventricose or wavy, ≤ 5 mm wide, free with regular edge. Stipe 70–150 × 5–10 mm, cylindrical to spirallike, gradually tapering towards the base to form a ± long (200–600 mm) underground pseudorhiza ± concolorous to the pileus, solid and fibrous. Annulus absent. Context whitish, ≤ 5 mm thick at the junction with the stipe. Spore-print greyish to brownish orange (6B4-6C4). Odour odorless.

Basidiospores (6.1–)7– 7.65 –8.5(–9) × (3.2–)3.5– 4.01 –4.5 μm, 1.77 ≤ Q ≤ 2.43, Q R = 1.91, subelliptic or ellipsoid, rarely ovoid or subcylindrical, ± thick-walled, hyaline with granulous content, containing one or more guttules, inamyloid. Basidia of two conspicuously different types by the thickness of their membrane and the number of sterigmata: first type fewer in number, thin-walled, clavate, 18–19 × 6.5–8 μm, bearing 4 sterigmata; second type rather abundant, very likely sclerobasidia due to their thick wall, clavate, 19–22 × 6–7 μm, bearing 1 to 4 sterigmata.. Pleurocystidia 11–22 × 6–12 μm, rare, thin-walled, clavate or with median constrictions, rarely subglobose or subclylindrical, rarely mucronate and sometimes showing an apical septum. Cheilocystidia 16–21 × 6–7 μm, rare, clavate, subutriform or showing median constrictions. Hymenophoral trama regular with hyphae 4–11 μm diam. Subhymenium pseudoparenchymatous with ± globose cells 5–8 μm diam. Context consisting of generally inflated hyphae, ≤ 15 μm diam., abundantly branched giving rise to a tufted structure. Pileipellis consisting of ± globose to ovoid cells, 22–50(–85) μm diameter.

Habitat, ecology and growth: Grows isolated, but in small groups in the vicinity of giant or subterranean termitarium, savannahs, opened spaces of forestry areas and cultivated plantations, usually during the great rainy season which extends from September to November in Cameroon.

Distribution: Collected only from Cameroon.

New specimen (isotype) examined.–– CAMEROON, Centre region, Village “Toutouli” in the suburbs of Yaoundé near the Nsimalen International Airport, 18 October 2005, collected by Njouonkou A.L., HUY1-DM 280C. The first description was based on the holotype (HUY1-DM 280B) of this form of T. striatus ( Mossebo et al. 2002) .

Termitomyces subumkowaan D.C. Mossebo , ( Figs. 9A View FIGURE 9 /B & Figs. 10A View FIGURE 10 /B/C/D), in Mossebo et al. Bulletin de la Société Mycologique de France 118(3): 224–228 (2002)

Synonymy: Termitomyces subumkowaanii Mossebo , Bulletin de la Société Mycologique de France 118(3): 224 –228 (2002)

Notes: –– The two collections [KM 143969 (HUY1-DM 260B) and HUY1-DM 260F] featuring on the same sub-clade C 1 with a bootstrap support value of 99% ( Fig. 1 View FIGURE 1 ) confirms T. subumkowaan as a new species of Termitomyces as originally described ( Mossebo et al. 2002) on the basis only of macro- and micromorphology.

Pileus 30–60 mm diam., up to 120 mm diam. at full maturity in some specimens, initially campanulate to subhemispherical, becoming convex to plano-convex; yellowish to brownish grey (4B2-6C2), surface viscous on freshly collected specimens, most often rimose at various lengths from the margins and showing an obtuse, ± conspicuous and concolorous yellowish to brownish grey (4B2-6C2) perforatorium. Lamellae whitish, concolorous to the context, 6–9 mm wide, initially adnate, becoming free with entire margin, crowded with lamellulae of different lengths. Stipe 80–160 × 10–20 mm, whitish (16A1) and subcylindric in its upper part, swelling towards the base to a diameter of 20-30 mm and dark to dark violet (16F3-16F4) from the lower half of the swelling downwards before abruptly tapering to form a 200–500 mm long and dark to dark violet (16F3-16F4) underground pseudorhiza, solid. Annulus absent. Context whitish, 10-17 mm thick. Spore-print brownish to pinkish brownish. Odour odorless.

Basidiospores 6– 6.75 –7(–8) × 4– 4.5 –5 μm, 1.33 ≤ Q ≤ 1.75, Q R = 1.52, hyaline, ellipsoid to subglobose, thin-walled, guttulate with a single guttule. Basidia 16–21 × 5–8 μm, clavate, most often bearing 2 sterigmata rounded at the tip, rarely with 1 or 4 sterigmata, generally with a granulous content and guttulate with one or several guttules. Pleurocystidia extremely rare and when present, resemble cheilocystidia. Cheilocystidia 16–24 × 7.5–12 μm, abundant, clavate to piriform, rarely utriform. Caulocystidia filamentous, translucent, and disseminated especially on the darkish lower part of the stipe as seen with the dissection microscope, measuring 0.2–0.7 mm long and 35–45 μm diam., thick-walled (membrane about 10 μm thick) becoming thinner at the apex. Hymenophoral trama regular, consisting of unclamped hyphae, 4–8 μm diam. Subhymenium pseudoparenchymatous, mixed up with ± rounded cells, 3–7 μm diam. Context consisting of branched, intermixed and partly inflated hyphae, 5–17 μm diam. Pileipellis consisting of upper layers of ± parallel repent hyphae 5–8 μm diam. and underneath lower layers consisting of inflated to subglobose hyphae 20–30 μm diam.; showing some clavate to subcylindrical pileocystidia 80–130 × 10–20 μm scattered over the pileipellis surface.

Habitat, ecology and growth: Grows in small groups in the vicinity of giant or mostly subterranean termites’ nests in savannahs, opened spaces of forestry areas and cultivated plantations, usually during the small rainy season which extends from early March to early June in Cameroon.

Distribution: Collected only from Cameroon.

Termitomyces medius Heim et Grassé View in CoL , in Heim: TERMITES ET CHAMPIGNONS. Les champignons termitophiles d’Afrique noire et d’Asie Méridionale, Edts Boubée, Paris: 128–137 (1977)

Notes: –– Termitomyces medius View in CoL was taxonomically revised based on some macro- and micromorphological characteristics observed on recently collected strains and so far undescribed by various authors including Heim (1977) and Pegler (1977). Also T. medius f. ochraceus View in CoL f. nov. was erected based on some key characteristics ( Table 2) conspicuously different from those of T. medius View in CoL . They include:

1. The perforatorium, conspicuously present ( Fig. 12A View FIGURE 12 arrow), resembling that of T. griseiumbo ( Mossebo et al. 2002) , brownish grey to greyish brown in T. medius in contrast with the pileus, but rather absent or in form of a concolorous pale yellow, brownish grey or greyish to brownish orange pseudo-umbo ( Fig. 12B View FIGURE 12 arrow) in T. medius f. ochraceus ,

2. The thickening at the base of the stipe ( Fig. 12A View FIGURE 12 left) most often present in T. medius and rather conspicuously absent in T. medius f. ochraceus ,

3. The structure of the pileipellis with intermixed repent and erected cells of different sizes in T. medius . It is made just of repent hyphae constantly measuring 10-13 μm in T. medius f. ochraceus ,

4. The thick- and thin-walled basidiospores, cheilocystidia and pleurocystidia in T. medius . These structures are just thin-walled in T. medius f. ochraceus .

It is here worth mentioning that T.medius (HUY1-DM372G)was originally identified as T.striatus f. griseiumboides ( Mossebo et al. 2002) based just on macroscopic and microscopic characteristics. It falls in the same highly supported clade E (100% bootstrap support value) with three other strains including T. medius f. ochraceus f. nov. described here, another strain of T. medius (dka 138) collected still in Cameroon by Frøslev et al. (2003), as well as a fourth strain of T. medius (KM 16685) collected (1990) in Nigeria, originally misidentified as T. striatus and conserved in Kew ( UK) under this name. Termitomyces medius was revised and T. medius f. ochraceu s f. nov. described as follows: