Lactarius kanadii Verma K., Mehmood, Uniyal & Sharma Y.P., 2022

Verma, Komal, Mehmood, Tahir, Uniyal, Priyanka & Sharma, Yash Pal, 2022, Lactarius indoevosmus and L. kanadii (Russulaceae), two new species from the northwestern Himalayas, India, inferred from morphology and molecular data, Phytotaxa 541 (2), pp. 165-177 : 172-175

Lactarius kanadii Verma K., Mehmood, Uniyal & Sharma Y.P. sp. nov. 2 Figs. 5 , 6 .

Mycobank:—MB842104

GenBank:— OL691266 (holotype), OL691518 (Paratype)

Diagnosis:—Basidiocarps with greyish brown to dark brown pileus; abundant watery white latex which changes to yellowish orange; globose to subglobose basidiospores with winged ornamentations ≥ 2 μm high.

Etymology:—In honor of Dr Kanad Das for his invaluable contribution to the systematics of Russulaceae in the Indian Himalayan Region.

Typification:— INDIA. Jammu and Kashmir: Kathua district, Samanamanj , 1750m, N 32 o 42.997ʹ E 075 o 25.931ʹ, 01 August 2020, Komal Verma, LK-011 ( CAL 1868 , holotype) .

Description:— Pileus 65–80 mm diam., initially convex, plano-convex at maturity, at times infundibuliform with depressed centre; surface velvety, greyish brown (6F3-4) to dark brown (6F7); margin undulate, decurved. Lamellae 4–5 mm broad, subdecurrent to decurrent, cream white (1A2) to greyish yellow (4B4), staining light brown (5C5) to brownish orange (5D5) after 15–20 minutes, crowded (10–12/cm), edges concolorous, staining yellowish brown (5D8) when damaged; lamellulae plentiful, unevenly distributed, 8–9 lengths. Stipe 60–80 × 10–18 mm, cylindric, slightly tapered towards apex, surface smooth, concolorous with pileus. Context brittle, white to cream white (5D8), staining light orange (6A4–5) on exposure, stuffed in stipe; not staining with FeSO4 and KOH, brownish red (8D7–8) in guaiacol. Latex abundant, watery white (1A1), changing to light orange (6A4–5) or yellowish orange (6A5–6) on lamellae. Taste mild. Odour pleasant. Spore deposit not obtained.

Basidiospores 6.8–8.17–9.5 × 6.0–7.8–9.0 μm, (n = 40, Q = 1.01–1.05–1.13), globose to subglobose, ornamentation composed of 1.5–2 μm high, winged, thick ridges and conical warts, short ridges between the larger ridges, forming an incomplete reticulum; plage inamyloid. Basidia 32–48 × 10–17 μm, subclavate, 2- or 4-spored; sterigmata 4.5–6 × 0.3–0.5 μm. Pleurocystidia absent. Pseudocystidia abundant, 7–9 μm diam., emergent up to 17–37 μm, unbranched. Cheilocystidia absent. Gill edges sterile. Cheiloleptocystidia abundant, 27–52 × 5–8 μm, emergent up to 10–25 μm, cylindric to clavate, apices round, with one to two cells at the base. Marginal cells 10–18 × 5–8 μm, cylindric to subclavate, often multiseptate, thin-walled, with brown intracellular pigmentation. Hymenophoral trama composed of abundant lactifers, up to 4–7 μm diam. Pileipellis a trichopalisade, 75–125 μm thick; suprapellis 40–55 μm deep, composed of cylindric to subclavate cells with brown intracellular pigmentation; subpellis 30–50 μm thick, composed of cylindrical to almost rounded cells. Stipitipellis a palisade to a trichopalisade, 38–55 μm thick; hyphae 6–8 μm diam., terminal cells with intracellular brown pigment.

Habit and habitat: — Scattered, under Quercus sp. and Pinus roxburghii in subtemperate mixed forest.

Additional specimens examined:— INDIA. Jammu and Kashmir, Kathua, Samanamanj , 1749 m, N 32º42.996ʹ E 075º25.931ʹ, 08 August 2020 K. Verma LK-021; Kathua, Garh 1700 m, 10 August 2020, K. Verma, LK-023 .

Notes:—Phylogenetically, Lactarius fuliginosus (98 % identity for 98–100 % query coverage using BLAST) and Lactarius picinus (98 % identity for 99–100 % query coverage using BLAST) are closest to Lactarius kanadii and these species could be confused in the field due to their similar macromorphology (basidiome shape, colors of pileus and lamellae). However, Lactarius picinus can be differentiated by its fuscous to brownish olive or sepia-coloured pileus, scant white latex which stains the lamellae salmon to reddish brown, slightly smaller, globose to broadly ellipsoid basidiospores, and its association with Picea sp. Lactarius fuliginosus , which is also close to Lactarius kanadii , can be differentiated by its velvety, greyish brown pileus, globose to broadly ellipsoid basidiospores with an almost complete reticulum, a pileipellis as a trichoepithelium, and its occurrence in coniferous and deciduous forests ( Heilmann-Clausen et al. 1998, Stubbe & Verbeken 2012). Lactarius atromarginatus can be differentiated from Lactarius kanadii by its marginate lamellae, abundant watery white latex that turns pale lilac and basidiospores with ornamentation forming a complete reticulum ( Verbeken & Horak 2000, Lee et al. 2018).

In the context of Indian representatives of L. subg. Plinthogalus, Lactarius nodulisporus and L. singeri could be confused with Lactarius kanadii due to the dark colored basidiomes. However, Lactarius nodulisporus can be segregated from Lactarius kanadii by its white latex, adnexed, distant lamellae and presence of nodulose ornamentation on the basidiospores (Uniyal et al. 2018). Lactarius singer differs from Lactarius kanadii in having a strongly rugose pileus with white context that remains unchanged on exposure, a palisadic pileipellis, a stipitipellis as a trichoderm and occurrence with Quercus sp. and Abies sp. (Uniyal et al. 2018).

Figures

FIGURE 5. Lactarius kanadii. a–d. Basidiomes in the field and basecamp; e. Gills showing latex; f. Bruising on pileus and stipe context; g. Basidia; h. Cheiloleptocystidia; i. Transverse section through pileipellis; j. Basidiospores under light microscope; k–m. Basidiospores under SEM. Scale bars: a, b = 20 mm, g–k = 10 μm. l = 5 μm. m = 2 μm. Photos by Komal Verma.

FIGURE 6. Lactarius kanadii. a. Basidia; b. Basidiospores; c. Marginal cells; d. Cheiloleptocystidia. e. Pileipellis; Scale bars: a, c–e = 10 μm b = 2 μm. Drawings by Priyanka Uniyal.