Craterellus inusitatus C.K. Pradeep & K.B. Vrinda, 2018

Bijeesh, C., Kumar, A. Manoj, Vrinda, K. B. & Pradeep, C. K., 2018, Two new species of Craterellus (Cantharellaceae) from tropical India, Phytotaxa 346 (2), pp. 157-168 : 162-166

Craterellus inusitatus C.K. Pradeep & K.B. Vrinda sp.nov. Figs.3 , 4

MycoBank MB: 823659

Etymology:— inusitatus (Latin) , in reference to the unusual shape of the basidiomata.

Diagnosis:—Distinguished from Craterellus pleurotoides by the unique macromorphology, white to cream pileus with scattered, agglutinated white strigose squamules; white, smooth hymenophore; mild sweetish taste; absence of clamp connections; unique habitat and distinct nrLSU sequence (MG593195).

Holotype:— INDIA. Kerala State: Trivandrum District, Palode, JNTBGRI campus, 20 September 2017, Bijeesh TBGT17113 ( CAL 1625 !)

Description:— Basidiomata small, thin, soft. Pileus 2–28 mm diam., cyphelloid, trumpet to cup shaped initially and in young ones, becoming applanate, dimidiate, pleurotoid, sometimes irregular in shape or petaloid-like, almost completely attached to the substratum by its abaxial side, not perforate; surface chalky white, cream (4A2/4A3/5A2) or pale grayish (5B2) towards base (near attachment to substratum), abaxial side with scattered, agglutinated, fibrillose, white, erect, strigose hairs, surface dry, non-hygrophanous; margin uneven, wavy, folded in a petalloid manner, crenulate or rarely incised, fringed with erect, white, strigose hairs. Hymenophore covering the entire adaxial side, white, smooth, without a demarcating zone. Stipe absent or reduced with a minute eccentric to lateral pseudostipe or attached abruptly to substratum. Pileal context very thin, white, soft. Odour mild but not distinctive. Taste mild, slightly sweetish.

Basidiospores 8–10(–11) × 6.5–7(–8) μm (Lm =9.74 ± 0.78, Wm =6.72 ± 0.47); Q=1.25–1.75; Qm=1.5, ellipsoid to broadly ellipsoid, smooth, inamyloid, thin-walled, with granular contents. Basidia 48–69 × 7–8 μm, long, narrow, subcylindric, subclavate, flexuous, thick-walled with large guttules or with finely granulose contents; sterigmata 2–3– 4–5; 7 μm long, stout, divergent, incurved. Basidioles abundant, cylindrical with finely granulose contents. Hymenial cystidia absent. Hymenophoral trama composed of branched hyphae, 6–8.5 μm wide, thin-walled, hyaline. Pileipellis a cutis, composed of short, thick-walled, 8–14 μm wide incrusted hyphae, interrupted by tufts of scale cells, 27– 35 × 7–8.5 μm, cylindrical, thin-walled, hyaline; the strigose scale cells at the pileus margin composed of slightly interwoven fascicles of hyphae with undifferentiated, cylindrical, terminal cells, 18–41 × 3–4 μm, thin-walled, hyaline. Clamp connections absent in all tissues.

Habit, habitat & phenology:—scattered, growing on living herbaceous plant stem, leaves of Pothos scandens ( Araceae ) on exposed root of Hopea parviflora , or on seedlings of Vateria indica and Hopea parviflora ( Dipterocarpaceae ), or on rocks, soil, in tropical evergreen forest, August–November.

Additional specimens examined:— INDIA. Kerala State: Thiruvananthapuram District, Palode , JNTBGRI campus, 31 August 2017, Bijeesh, TBGT17073 ; ibid, 13 September 2017, Bijeesh, TBGT17093 ; ibid, 20 September 2017, Bijeesh, TBGT17113 ; ibid, 21 September 2017, Bijeesh, TBGT17124 ; ibid, 22 September 2017, Bijeesh, TBGT17127 ; ibid, 3 October 2017, Bijeesh, TBGT17136 ; ibid, 7 October 2017, Bijeesh TBGT17190 ; ibid, 7 November 2017, Bijeesh, TBGT17251 ; Kollam District, Kulathupuzha , 21 September 2017, Bijeesh, TBGT17114 .

Comments:— Craterellus inusitatus is unusual in its shape of the basidiomata and its habitat on stems, leaves, bark, roots and seedlings of plants of Araceae and Dipterocarpaceae .

Craterellus pleurotoides (T.W. Henkel, Aime & S.L. Mill.) A.W. Wilson (2012: 1475) originally described as Cantharellus pleurotoides T.W. Henkel,Aime & S.L. Mill. (2006: 1410) from Guyana resembles C. inusitatus in having cyphelloid, pleurotoid, astipitate basidiomata, the smooth hymenophore covering the entire lower surface and in habitat. However, C. pleurotoides differs from C. inusitatus by the olive yellow pileus, the hymenium that becomes orangeyellow, the subglobose basidiospores (8–10.5 × 6.5–8.5 μm), 3–6 sterigmate basidia, abundant clamp connections and presumed EcM association with Dicymbe ( Fabaceae ) species. Craterellus inusitatus and C. pleurotoides also have distinct nrLSU sequences and are phylogenetically distantly related to each other ( Fig. 5 ). It is evident the pleurotoid or petaloid shapes of the basidiomata have evolutionarily converged in separate tropical habitats.

In general morphology and in some microscopic features, Cantharellus cyphelloides Suhara & S. Kurogi (2015: 2) from Japan is similar to C. inusitatus , however, nrLSU rDNA sequence analysis clearly place that species under Cantharellus in the subgenus Cinnabarinus clade.

In a BLASTn search using the nrLSU sequence from C. inusitatus (940bp), the closest hit was C. indicus (HM113529) with 98% sequence identity (921/943). The ML and BI analyses generated trees with similar topological congruence, in which C. inusitatus is nested in a subclade with C. indicus , (HM113529, HQ450770, HQ450771) C. shoreae (KY290585) and C. parvogriseus (MF421098) with strong 99% ML bootstrap and 1.0 Bayesian PP support. However, these species are quite distinct both macro and microscopically by the pileate, stipitate basidiomata, 4- sterigmate basidia and large basidiospores.

Figures

FIGURE 3. Craterellus inusitatus. A–F. basidiomata with unusual shape and on different substratum. Scale bar=10 mm. Photos: C. Bijeesh

FIGURE 4. Craterellus inusitatus. A–B. basidia. C. spores. D. pileipellis E. pileal fasciculate scale elements. F. fasciculate scale cells in pileal margin. Scale bar, A–C=10 μm. D–F=20 μm. Photos: C. Bijeesh

FIGURE 5. Phylogenetic analysis of Craterellus species inferred from nrLSU sequences. Bootstrap values (ML, ˃50%) and Bayesian posterior probabilities (BI, ˃0.90) are shown above/below branches.Values to the right and left of the ‘/’ are ML-BS and BI-PP respectively. GenBank accession numbers are given after the taxonomic names.