Parapterulicium subarbusculum Corner, Ann. Bot., 16: 288 (1952)

Leal-Dutra, Caio A., Neves, Maria Alice, Griffith, Gareth W., Reck, Mateus A., Clasen, Lina A. & Dentinger, Bryn T. M., 2018, Reclassification of Parapterulicium Corner (Pterulaceae, Agaricales), contributions to Lachnocladiaceae and Peniophoraceae (Russulales) and introduction of Baltazaria gen. nov., MycoKeys 37, pp. 39-56 : 40

Parapterulicium subarbusculum Corner, Ann. Bot., 16: 288 (1952) Fig. 2

Description.

Basidiomes coralloid/filiform, up to 35 mm high, branched, erect, monoaxial with adventitious branches, yellow (10YR 8/6), solitary or gregarious. Stipe up to 13 × 0.3-0.7 mm, glabrous, concolorous with the rest of the basidiomes, attached to a small resupinate base up to 3 mm wide. Branches up to 1.3 × 0.2 mm, tapering upwards, rarely with branchlets.

Habitat: On dead twigs, petioles, leaves or seeds in the forest.

Hyphal system dimitic. Generative hyphae up to 7 μm wide thin-walled, without clamps. Skeletal hyphae 2-7 μm wide, thick-walled (up to 1.3 μm), rarely branched. Abundant dextrinoid dichophyses, up to 30 μm wide, slightly thick-walled (0.5-1 μm), branching with filiform ends, tips less than 0.5 μm wide.

Resupinate patch not well-developed in the studied material but with abundant dichophyses.

Basidia not observed.

Gloeocystidia up to 65 μm long, clavate to lanceolate/subulate, thin-walled, with numerous internal droplets, IKI-.

Basidiospores (12 –)13.4–16.8(– 17) × 3-3.5 μm (n = 19), hyaline, smooth, elongate, subfusiform, apex obtuse, base acute with small apiculus (0.3 μm), thin-walled and slightly amyloid, scarce in all the collected samples.

Specimens examined.

Brazil. Rio de Janeiro: Rio de Janeiro, Parque Nacional da Tijuca, close to Casa do Pesquisador, growing on the ground in rainforest litter, 24-25 Nov 2014, C.A. Leal-Dutra 108, 109, 117,118, 119, 120, 121, 122 (topotypes designated here: RB 639457, RB 639458, RB 639462, RB 639463, FLOR 56456, FLOR 56457, FLOR 56458, FLOR 0056459).

Distribution.

Brazil. Rio de Janeiro: Rio de Janeiro ( Corner 1952a, Type)

Notes.

This species is recognised in the field by its characteristic resupinate disc at the base of the stipe (Fig. 2b, c). Corner (1952a) described P. subarbusculum from a single specimen collected in November 1948 on Corcovado in Rio de Janeiro and, based on its coralloid habit and dimitic hyphal system, placed the genus in Pterulaceae . The presence of gloeocystidia, slightly amyloid spores and dextrinoid dichophyses corroborates its placement in Russulales . It appears to be relatively common, though apparently overlooked.