Mycetinis curraniae (G. Stev.) J. Cooper & P. Leonard in Cooper., 2012. Index Fungorum no. 3: 1.

Petersen, Ronald H. & Hughes, Karen W., 2017, An investigation on Mycetinis (Euagarics, Basidiomycota), MycoKeys 24, pp. 1-138 : 20-25

5. Mycetinis curraniae (G. Stev.) J. Cooper & P. Leonard in Cooper., 2012. Index Fungorum no. 3: 1.

Marasmius curraniae Basionym. G. Stevenson. 1964. Kew Bull 19(1): 39.

Holotype.

New Zealand, North Island, Wellington, Butterfly, S41°00', E175°23', 11.III.1958, coll. M. Curran, Stevenson 1247 (K; annot. Desjardin; annot. Johnston).

Diagnosis.

1) Basidiomata diminutive (pileus 5-16 mm broad; stipe 6-15 × 0.5-1 mm); 2) pileipellis a hymeniform layer of inflated hyphal termini, often with small knobs or coralloid outgrowths; 3) cheilocystidia similar to pileipellis cells, diverticulate; 4) spores 7-8 × 4-4.5 µm, ellipsoid, collybioid (not tapered proximally or distally); 5) fruiting on rotting bark and twigs of myrtaceous hosts; 6) distribution in New Zealand.

Basidiomata (Fig. 28) diminutive, solitary or in small clusters. Pileus 5-16(-20) mm broad, strongly convex when young, expanding in age to plano-convex sometimes with a slightly depressed disc, occasionally with low, broad umbo, shallowly subsulcate at the margin, pale beige-brown with reddish brown tones when young, disc remaining so in age, becoming paler toward the margin, dull, dry, minutely furfuraceous-punctate over disc. Subpellis hyphae interwoven, 3-6.5 µm diam, firm-walled, apparently involved in a slime matrix; clamp connections sporadic, not universal. Pileus trama tough, supple when fresh, buff to pale concolorous with pileus surface; pileus tramal hyphae thin-walled to thick-walled, subgelatinous, inamyloid. Lamellae adnate to slightly decurrent, subdistant, often weakly pseudocollariate, total lamellae (23-)26-38, through lamellae 7-9, subventricose, up to 1.5 mm broad, rarely with buttresses, off-white to pale cream or pale beige, taking on slight pinkish tint upon drying and storage; lamellar edge minutely fimbriate, concolorous with lamellar face; lamellulae poorly developed, in two series. Stipe strongly curved to nearly straight, central or occasionally slightly eccentric, 6-15 × 0.5-1.0 mm, terete, cylindrical, equal or slightly attenuate downward, tough, solid, insititious to expanded at base, appearing erumpent, apex minutely pulverulent, downward appearing glabrous to sparsely silky; stipe apex cinnamon, orange-brown to dark reddish brown, downward darker to almost black near base. Rhizomorphs not observed. Odor and taste strong, like garlic.

Habitat and phenology.

Known only from New Zealand (both islands); solitary or in groups on rotting bark of twigs, living, standing trees and/or logs of myrtaceous trees ( Leptospermum sensu lato, Metrosideros umbellata ) (teste Horak). PDD reports nine collections from substrates Kunzea ericoides , Dacrydium cupressum and Cupressus macrocarpa ; mid-summer to autumn (Jan-May)

Pileus disc pileipellis (Fig. 29) constructed of two elements: 1) repent hyphae 5-8.5 µm diam, firm- to thick-walled (wall -1 µm thick, hyaline), coarsely encrusted, obscurely clamped; and 2) inflated hyphal termini 11-22 µm broad, in an interrupted layer, stalked (stalk 3-35 × 3-9 µm), thick-walled (wall 0.7-1.4 µm thick, hyaline or occasionally weakly pigmented), usually very finely encrusted or roughened, either without outgrowths, with scattered papilla-like outgrowths (usually 1-3 × 1-1.5 µm, rounded), or with complex, branched, coralloid outgrowths 4-20 µm long, with branches 2-2.5 µm broad, repeatedly branched, flaccid. Underlying interwoven hyphae 3-6.5 µm diam, firm-walled, apparently involved in a slime matrix; clamp connections sporadic, not universal. Pleurocystidia (Fig. 30 A–D) plentiful, 33-39 × 4-7 µm, narrowly fusiform to fusiform, conspicuously clamped; contents more or less homogeneous. Basidioles clavate to (occasionally) subampulliform; basidia (Fig. 30 E–H) 24-35(-40) × (4-)7-9 µm, clavate, (2-)4-sterigmate, obscurely clamped; sterigmata subcornute; contents heterogeneous, multiguttulate. Basidiospores (Fig. 31) (6.5 –)7– 8(-10) × 4-4.5(-5) µm (Q = 1.50-2.00; Qm 1.76; Lm = 7.4 µm), ellipsoid, flattened somewhat adaxially, smooth, thin-walled, inamyloid. Cheilocystidia (Fig. 32) locally common, 27-40 ×10– 16 µm overall, stalked (stalk 5-29 × 4-9 µm, thick-walled), expanded distally to 10-16 µm broad, surmounted by a cluster of diverticula; diverticula (1-)2-7 × 1-1.5 µm, digitate, often dichotomous, hardly refringent. Stipe medullary hyphae (2-)5-11 µm diam, strictly parallel, free (not involved in a slime matrix), firm- to thick-walled (wall -2 µm thick, hyaline, often fluctuating in thickness), conspicuously clamped. Stipe cortical hyphae 4-14(-16) µm diam, thick-walled (wall -2 µm thick, pigmented yellowish), producing two types of caulocystidia (Fig. 33); 1) widely scattered narrow-necked lobes, 4-15 × 4.5-7.5 µm, hyaline, firm- to thick-walled (wall -1 µm); and 2) repent caulocystidial hairs 15->250 × 4-7.5 µm, thick-walled (wall -2 µm thick, hyaline to weakly yellowish), usually slightly subcapitulate apically, smooth to minutely roughened.

Commentary.

M. curraniae produces diminutive basidiomata similar to those of My. cinnamomeus , My. olidus , My. scorodonius f. diminutivus , My. virgultorum and My. yunnanensis , usually fruiting in small clusters or troops on woody material. Stevenson’s (1964) description reported features not observed subsequently, including weakly “pseudo-amyloid” (?dextrinoid) elements in pileus and lamellar tramae, pruinose stipe, "faintly amyloid" inflated pileipellis structures.

Pileipellis structures appear to be very finely roughened. This may be caused by a thin slime layer covering the pileipellis and certainly produced in the pileus trama as well. Pileipellis structures and cheilocystidia are not discretely defined and photos are difficult to interpret and depict. For this reason, line drawings are supplied to represent the structures in photos of these structures.

Desjardin and Horak (1997) drew attention to some similarities between My. curraniae and M. cinnamomeus Cleland (1934). Grgurinovic (1997) supplied a more detailed description of the latter, but by not citing a holotype, implied that a holotype (South Australia, National Park, Mt. Lofty, Willunga Hill, Innan Valley, teste Cleland) was unavailable. Desjardin and Horak (1997) concluded that My. curraniae and M. cinnamomeus were distinguishable at least as follows: 1) apparently no odor of garlic (noted as "odor none" by Cleland for M. cinnamomeus ); 2) larger spores (9-12 × 4.5-6.0 µm teste Desjardin and Horak) of M. cinnamomeus ; and 3) M. cinnamomeus fruiting on the base and bark of living Eucalyptus .

Specimens examined.

New Zealand, North Island, Prov. North Auckland., Little Barrier Island, Tinkawa Stream, S36°11'56.60", E175°04'54.73", 14.V.1981, coll E. Horak, det. DE Desjardin [as Marasmius curraniaii (sic)] Horak 949 (ZT, SFSU). New Zealand, South Island, Prov. Westland, Rotomantu, Lady Lake, S43°35'56", E171°34'41", 25.III.1983, coll E. Horak, det. DE Desjardin [as Marasmius curranii (sic)] Horak 2101 (SFSU).