Lactarius bisporus Verbeken & F. Hampe, 2014

Verbeken, Annemieke, Hampe, Felix, Wissitrassameewong, Komsit, Hyde, Kevin, Eberhardt, Ursula & Nuytinck, Jorinde, 2014, A new angiocarpous Lactarius species from Thailand, Phytotaxa 181 (3), pp. 163-170 : 166-167

Lactarius bisporus Verbeken & F. Hampe sp. nov. ( Figs. 2–3)

Mycobank number: MB 807217

Diagnosis: Basidiomata 10–35 mm diam., 10–15 mm alta, subglobosa, subregularia. Peridium leviter velutinosum, ochraceum ad luteobrunneum. Stipes absens. Gleba labyrinthuloidea, albida, cum locis parvis, cum paucis venis gelatinosis. Columella absens. Latex excarsus, albidus, immutabilis. Sporae globosae ad subglobosae, 9.8–11.3–13.0 × 9.8–11.2–12.5 µm, amyloideae, spinis et verrucis usque ad 2(3) µm altis ornatae, macula suprahilaris non amyloidea. Basidia 45–55 × 12–18 µm, bispora, subcylindrata ad clavata. Cystidia 25–55 × 12–20 µm, cylindrata, clavata vel utriformia. Peridiopellis ex hyphis periclinis.

Typus: — THAILAND. Chiang Mai Province, Mae On District, about 3 km from Tharnthong Lodges , 725 m elev. N18°51’55’’, E99°17’23’’, 17 July 2012, leg. Felix Hampe, FH 12–160 (holotype, GENT!), MFLU 12–0650 (isotype, MFLU!) .

Etymology: —referring to the strictly 2-spored basidia.

Basidiocarps angiocarpous, semihypogeous, 10–35 mm diam., 10–15 mm high, subglobose, rather regular. Peridium with minutely velutinous surface, chamois-leather-like, ochraceous yellow to yellow-brown. Stipe absent. Columella absent. Gleba whitish, strongly labyrinthuloid, with small loci, with some, but very few, gelatinous veins between the loci. Latex scarce, whitish hyaline, unchanging on the gleba and unchanging on white paper, unchanging with KOH. Taste bitter to astringent, disagreeable but not burning acrid. Smell not remarkable. Basidiospores globose to subglobose, 9.8– 11.3 –13.0 × 9.8– 11.2 –12.5 µm, Q = 1.00– 1.01 –1.04, n = 20; ornamentation amyloid, consisting of isolated, up to 2(3) µm high spines and isolated warts; spines conical, subacute, with rounded to tapering, rarely forked apex; apiculus up to 2.5(3) µm long; plage not distinct, inamyloid. Basidia 2-spored, subcylindrical to clavate, sometimes irregular and somewhat tortuous, 45–55 × 12–18 µm, with 5–12 µm long sterigmata. Macrocystidia very variable in shape, clavate, subcapitate, ventricose or lageniform, 25–55 × 12–20 µm, sometimes slightly but distinctly thick-walled. Pseudocystidia present. Peridiopellis consisting of 2–3 µm broad hyphae which are rather periclinally arranged in the subpellis, but form a densely intricate and interwoven layer on top and are embedded in a gelatinous matrix.

Habitat: —primary tropical forest with Dipterocarpus tuberculatus Roxb. Known only from the type collection.