Russulales » Russulaceae » Lactarius

Lactarius aurantionitidus

Lactarius aurantionitidus Wisitrassameewong & G. Jiayu

MycoBank number: MB812831 Facesoffungi number: FoF 00854.

 

Pileus 40–48 mm, broadly planoconvex to infundibuliform with depressed centre; surface viscid and glossy, irregular, rather unicolourous, light orange (5A5–A6) to greyish orange (5B4–B6) or sometimes paler, pale cream, sometimes with olive brown tints (4E4–E5); margin shortly striate, crenulate. Lamellae decurrent, up to 3 mm broad, crowded, with 4 lamellulae of different lengths, yellowish white (4A2) to pale yellow (4A3), orange brown when bruised. Stipe 40 × 5mm, cylindrical; surface slightly wrinkled, dry to slightly viscid, concolourous, paler on top, with brown tints, often with whitish mycelium at base. Context 3 mm thick in pileus, pale cream, partly hollow to hollow in stipe; odour indistinct, taste mild. Latex watery white, copious, unchanging on exposure; taste mild. Basidiospores mostly ellipsoid, rarely subglobose, 7.8–8.7 8.8–9.6 (–10.0) × 6.2–6.9–7.2–8.0 (–8.4) mm, Q ¼ 1.10–1.21–1.26–1.35 (n ¼ 40); ornamentation amyloid, up to 1 mmhigh, consisting of isolated warts and short and low ridges connected by thin lines, obtuse; plage distally amyloid. Basidia 58–65 × 18–20 mm, 4espored, subclavate to clavate, with fine granules and guttate contents. Pleuromacrocystidia abundant, 112–143 × 13–17 mm, projecting up to 70 mm, subfusiform, with mucronate to moniliform apex, with fine granules and guttate contents. Pleuropseudocystidia abundant, 3–6 mm diam., cylindrical, straight to tortuous, with round apex, fine granules. Lamellae edge heterogeneous, consisting of basidia, marginal cells and cheilocystidia; marginal cells 26–30 × 6–14 mm, subcylindrical to subclavate; cheilocystidia abundant, 33–70 × 8–14 mm, slightly emergent, subfusiform, with mucronate apex, with fine granules. Lamellar trama consisting of lactifers, filamentous hyphae and sphaerocytes. Pileipellis an ixotrichoderm, covered by a thin to thick slime layer, 100–150 mm thick, consisting of cylindrical hyphae, which are bent to erect and enlarged up to 10 mm diam.

Habitat: solitary or gregarious, growing under Pinus densata, Picea likiangensis, Rhododendron rubiginosum, and Betula platyphylla.

Studied material: China, Yunnan Prov., Diqing Tibetan Autonomous Prefecture, Heping village, mixed forest dominated by Pinus densata, Picea likiangensis, Rhododendron rubiginosum, and Betula platyphylla, N27_28.340 E99_50.920, 3341 m alt., 05/09/2012, xp3e20120905e06 (Holotypus, KUN!, Isotypus, GENT!); Yunnan Prov., Diqing Tibetan Autonomous Prefecture, Heping village, mixed forest dominated by Pinus densata, Picea likiangensis, Rhododendron rubiginosum, and Betula platyphylla, N27“28.340 E99”50.920, 3291 m alt., 17/08/2013, ZD1147

 

 

Fig. 1 An ITS tree of Lactarius subg. Russularia. The thick branches indicate supported clades. Bootstrap support and posterior probabilities are indicated when they exceed 75 % and 0.95 %. New species in this study are in boldface.