Lactarius (sect. Uvidi) Bon

Key to the species of Lactarius sect. Uvidi known worldwide 1a. Cap violaceous to brownish or greyish..............................................................................................................................................2 1b. Cap cream to yellowish....................................................................................................................................................................12 2a. Habitat sub-alpine (> 2700 m).............................................................................................................................................................3 2b. Habitat temperate deciduous (800–2700 m).......................................................................................................................................5 3a. Basidiospores densely reticulate; cap greyish buff to clay buff................................................................................. L. pseudouvidus 3b. Basidiospores incompletely reticulate; cap brownish to vinaceous...................................................................................................4 4a. Cap brownish vinaceous, grey to dark vinaceous; larger basidiospores (8.8–11.9 × 6.7–8.6 μm); odor of cedar-oil...................................................................................................................................................................................................... L. brunneoviolaceus 4b. Cap umber to sienna to brown vinaceous; rather smaller basidiospores (8.0–10.5 × 6.9–8.8 μm); odor of pear.......... L. pyriodorus 5a. Pileus with a distinct papillate umbo (papilla up to 7 mm high).................................................................................... L. hrdovensis 5b. Pileus without any papilla..................................................................................................................................................................6 6a. Cap slightly zonate with watery or vinaceous spots, greasy but not slimy.......................................................................... L. luridus 6b. Cap hardly zonate with no such spots, slimy, viscid to glutinous......................................................................................................7 7a. Cap covered with bundles of glutinous hairs.................................................................................................................... L. formosus 7b. Cap never covered with glutinous hairs.............................................................................................................................................8 8a. Basidiospores with rounded warts and ridges....................................................................................................................................9 8b. Basidiospores never with rounded warts and ridges........................................................................................................................10 9a. Stipe slender, shiny when dry, slightly slimy when young and fresh.................................................................................... L. uvidus 9b. Stipe thick, dry and unpolished, not becoming shiny....................................................................................................... L. montanus 10a. Cap never zonate; taste bitter; context turning pale violet to greyish violet on exposure, basidiospores 6.0–9.5 × 5.0–8.0 μm........................................................................................................................................................................................... L. indoviolaceus 10b. Cap azonate to zonate; taste mild or acrid; context turning violet to purple on exposure, basidiospores 7.5–11.3 × 6.4–8.5 µm................................................................................................................................................................................................................11 11a. Taste mild; cap greyish buff to brownish violet; context turning dark purple on exposure; larger basidiospores 7.6–11.3 × 6.4–8.5 µm.................................................................................................................................................................................... L. violascens 11b. Taste acrid; cap pale olive; context turning violet on exposure; smaller basidiospores 7.5–9.5 × 7–8.5 µm....... L. olivaceopallidus 12a. Cap margin bearded or hairy; fruitbodies medium to large (30–160 mm).......................................................................................13 12b. Cap margin smooth or tomentose only when young; fruitbodies smaller (10–70 mm)...................................................................14 13a. Cap whitish chrome to pale cream, hairy only at margin; stipe short (length 20–30 mm)........................................ L. dryadophilus 13b. Cap brighter yellow, abundant hairs and scales all over; stipe long (length 40–125 mm).................................... L. repraesentaneus 14a. Cap 10–50 mm.................................................................................................................................................................................15 14b. Cap larger (> 50 mm)........................................................................................................................................................................16 15a. Fruitbodies slender and fragile; cap sometimes ochraceous in the centre, margin hardly crenulate; basidiospores almost reticulate............................................................................................................................................................................. L. salicis-herbaceae 15b. Fruitbodies not quite fragile or slender; cap with no such ochraceous color, margin sometimes crenulate; basidiospores not reticulate.............................................................................................................................................................. L. salicis-reticidatae 16a. Lamellae and context turning dark brownish violet to dark livid red when bruised; taste acrid; basidiospores ornamentation reaching 1 µm high............................................................................................................................................................................. L. flavidus 16b. Lamellae and context turning lilac when bruised; taste mild to bitter; basidiospores ornamentation reaching 0.5 µm high......................................................................................................................................................................................................... L. aspideus
Published as part of Bera, Ishika, Das, Kanad & Datta, Bejoysekhar, 2022, A new species of Lactarius sect. Uvidi (Russulaceae) from India, pp. 203-212 in Phytotaxa 576 (2) on pages 209-210, DOI: 10.11646/phytotaxa.576.2.6, http://zenodo.org/record/7461320