Sistotremastrum limonadense G. Gruhn & P. Alvarado, 2021

Gruhn, Gérald & Alvarado, Pablo, 2021, Sistotremastrum limonadense sp. nov. from French Guiana, Phytotaxa 498 (1), pp. 35-43 : 36-39

Sistotremastrum limonadense G. Gruhn & P. Alvarado , sp. nov. ( Figs 2–3 )

Mycobank: MB 834196

Diagnosis: differs from Sistotremastrum guttuliferum by the absence of oil drops in the cytoplasm of subicular hyphae, the smooth to tuberculate basidiomata and a different genetic profile.

Holotype: FRANCE: French Guiana, Saül, D. Diadema trail, on bark of an unidentified dead trunk lying on the ground, 22 Oct 2013, leg. G. Gruhn, LIP 0001683 .

Etymology: the epithet refers to the name of the river “crique Limonade” near the temporary camp built during the field trip in French Guiana when the specimens were collected.

Basidiome annual, widely effused (up to 12 × 8 cm), adnate, deeply attached to the substrate. Hymenium tuberculate and white when fresh; smooth and cream colored in herbarium. Context subceraceus, composed of a single homogeneous layer 75–100 µm thick, white when fresh, light cream after drying, rarely cracking in rounded patches due to subiculum hyphae stretching. Margin gradually thinning out, porulose in herbarium, concolor with the hymenium; with thin hyphal cords scattered in the substrate and subiculum. Hyphal system monomitic; hyphae densely joined in a compact context but easily squeezed under the cover slip, leaving short-celled hyphal fragments with thin walls about 3.5–4 µm wide. Hyphae in subiculum and cords firm-walled, 4.5–6 µm wide, composed of long cells with rounded clamp connections present at all septa. Oil drops not found in hyphae. Hyphidia and cystidia not seen. Basidia measuring 16–20(–25) × 6–8(–9) µm, at first ovoid, clavate to utriform when mature, stout, with typical flattened apex, thin-walled, fragile and easily broken when mounted, clamped, with 6–8 short and thin sterigmata. Spores white on spore print, cylindrical to ellipsoid, [35] (5.0–)5.5–7.0(–7.5) × (2.5–)3.0–3.5(–4.0) µm, smooth and thin-walled, lacking oil drops in the protoplasm, inamyloid, indextrinoid, and acyanophilous.

Specimens examined: FRANCE: French Guiana, hbG GUY13-090 (isotype) and GB (isotype), 22 Oct 2013, Saül, D. Diadema trail, on slope, on bark of an unidentified dead hardwood, leg. & det. G. Gruhn; hbG GUY13-085, GB (paratype), Ibid; GUY13-092, GB (paratype), Ibid .

Other specimen examined for this article:— Sistotremastrum guttuliferum : PORTUGAL: typus, MA-fungi 82105, 16566-Tell, Madeira Island, Santana, Levada da Fajã, on wood; SWITZERLAND: hbM EM-9594 (hbG 180623-008), Meride, Bolle (Ticino), alt. 650m, on wood of a lying, moist, rather hard trunck of Tilia cordata , leg. & det. E. Martini; hbM EM-10075 (hbG 180623-007), Meride, Veschee (Ticino), alt. 760m, on wood of a lying, moist, rather dry decayed trunck of Tilia cordata , leg. & det. E. Martini; hbM EM-12235 (hbG 180623-006), Mondada, Gramusèd (Valle Bavona, Ticino), alt. 620, on lying decayed trunk of hardwood, leg. & det. E. Martini; hbM EM- 12826 (hbG 180623-009), Ascona, Gratena (Ticino), alt. 339m, on a lying, rather dryed hardwood, leg. & det. E. Martini. Sistotremastrum niveocremeum : FRANCE: hbT GT-94014, 26 Jan 1994, Ottange (Moselle), on souche of Picea abies , leg. & det. G. Trichies; hbT GT-94026, 29 Jan 1994, Neufchef (Moselle), on dead stem of Rosa canina , leg. & det. G. Trichies; hbT GT-01016, 26 Jan 2001, Beuvange-Saint-Michel (Moselle), on hardwood log, leg. & det. G. Trichies; hbT GT-03073, 10 Sept 2003, Neufchef (Moselle), near a mine, on a coniferous board, leg. & det. G. Trichies. Sistotremastrum roseum : INDIA: PUN 5057, typus, Himachal Pradesh, Chamba, Dalhousie, Ahla, on fallen gymnospermous log. Sistotremastrum suecicum : FRANCE: hbT GT-11053, 13 Sept 2011, Neufchef (Moselle), White road, on a coniferous board, in a career, leg. & det. G. Trichies.

Figures

FIGURE 2. Sistotremastrum limonadense sp. nov. (holotype). Spores observed in Melzer, basidia, and basal hyphae observed in KOHphloxine. Scale bar associated to drawings: 10 µm.

FIGURE 3. Sistotremastrum limonadense sp. nov. (holotype). Basidiome on the field.