Coniolepiota spongodes (Berk. & Broome) Vellinga, in Vellinga et al., Mycologia 103(3): 502 (2011)
Pileus 15–110 mm, campanulate to wide-conical, plano-convex to applanate with slightly inflexed margin, when young covered in lilac, purple-gray (K. & W. 12EF4–5, 11E4, 11–12D3 to 13C3) powdery velar warts, later still covered in center, but in outer zone often gone and showing white to whitish background; covering thick at center, and the powdery warts a bit spread out in outer 1.5 cm, some overhanging margin; marginal zone smooth or slightly fissured, when young exceeding lamellae. Lamellae, L = c. 80, 1 = 1–3, free and remote from stipe with distinct gutter, crowded, not or slightly ventricose, 3–9 mm wide, in some specimens furcate to anastomosing, off white, pale cream to pale yellow, with even to eroded, concolorous edge. Stipe 40–100 x 4–11 mm, cylindrical or tapering upward and slightly wider (up to 8 mm) at base, off white at apex, in lower four-fifths of length with bands of powdery material as on pileus (e.g. 12D3), brown in basal part from handling, hollow, with white tomentose mycelial growth at base. Annulus thin membranous to cortina-like, often attached to pileus margin, white-flocculose above, flocculose and gray-lilac (13C3) on underside. Context thick in pileus, white and dull, in stipe shinysatiny, whitish to brownish in lower one-third, rarely pinkish. Odor like that of Lepiota cristata but without the sweetness, or unremarkable and fungoid. Taste fungoid, mild. Spore print white.
Basidiospores [99,5,5] in side view 4.4–6.4 x 2.7– 3.7 µm, avl x avw 5 4.8–5.1 3 3.0–3.2 µm, Q = 1.4– 1.8, av Q = 1.55–1.6, ellipsoid to oblong with flattened abaxial side and rounded apex, ellipsoid to oblong in frontal view, thick-walled, with guttule, with congophilous contents, blue in cotton blue, with pink line around dark blue contents and non-colored wall in cresyl blue, slightly and slowly turning orange in Melzer’s reagent. Basidia 11–21 x 5.0–7.0(–8.0) µm, four-spored. Lamella edge sterile, with a band of inconspicuous cheilocystidia. Cheilocystidia 13–25 x 6–13 µm, clavate to broadly clavate, some narrowly clavate, hyaline, not colored, sometimes difficult to find. Pleurocystidia not observed. Lamella trama made up of non-colored, inflated long cells, 5–20 µm diam. Pileus covering a powdery layer made up of cylindrical to irregularly branched hyphae, t-shaped or with more side branches, forming a threedimensional structure; individual cylindrical cells 29–60 x 4–10 µm, with refractive connecting points, with lilac parietal, sometimes fine incrusting, pigment. Stipe covering as pileus covering. Clamp connections absent.
Habitat and distribution: Solitary or in small groups, saprotrophic, on clayey soil, on banks and trails, in disturbed areas of native rainforest, or in lowland rainforest, fruiting during rainy season. Jun-Sep northern Thailand, Singapore, Malaysia, also known from Sri Lanka.
Index fungorum number: IF518494
Notes: Pegler (1972) studied the type collections of C. spongodes and L. euconiata and concluded, just like Petch (1917), that C. spongodes represents an older version of L. euconiata; he described the species as follows: ‘‘This is a large attractive species, readily recognized by the purplish to lilaceous pulverulent covering of the pileus and stipe.’’ This description perfectly fits the here described and illustrated species. Microscopically it is striking because of the three-dimensional structure of the pileus-covering elements, the absence of clamp connections, inconspicuous cheilocystidia (hard to find in some specimens) and relatively small, smooth spores. Pegler (1972, 1986) noted that the spores of L. spongodes are dextrinoid. In the Thai material studied the spores are pale or not colored at all in Melzer’s reagent. Hymenagaricus ardosiaecolor (Heinem.) Heinem. has comparable elements in the pileus covering but has a brown floccose pileus, brown stipe, brown spores and brown contents in the cheilocystidia and pileus covering elements (Heinemann 1956).
Figure 1. rpb2 phylogeny of the Agaricaceae inferred by maximum likelihood (ML) analysis. Numbers at internodes refer to confidence estimates based on 100 rapid ML bootstraps (only those ˃ 70 are given). Coniolepiota and Eriocybe are highlighted, and main clades are indicated. Amanita brunnescens and A. muscaria, Hebeloma olympianum, Strobilomyces strobilaceus and Tubaria vinicolor are outgroup taxa.
Figure 2. Phylogeny of Agaricus and satellite genera in the Agaricaceae based on nrITS sequences, inferred by maximum likelihood (ML) analysis. Numbers at internodes refer to confidence estimates based on 100 rapid ML bootstraps (only those ˃70 are indicated). Coniolepiota and Eriocybe are highlighted, and genus Agaricus and the Agaricus clade indicated. Leucoagaricus barssii and La. leucothites are outgroup taxa.
Figure 3. A phylogeny of the Agaricaceae inferred by maximum likelihood (ML) analysis of a combined nrLSU, rpb2, tef1 and nrITS dataset. Numbers above branches refer to posterior probability scores before the / (those ˃ 0.94 are given) and confidence estimates based on 100 rapid ML bootstraps (only those . 75% are indicated) after the /; the numbers below the branches are bootstrap support values from the parsimony analysis (˃ 75%). Thick branches have a posterior probability ˃ 0.94, and both bootstrap values ˃ 75.