Lactarius resinosus X.H. Wang, 2019

Wang, Xiang-Hua, Das, Kanad, Bera, Ishika, Chen, Yu-Hui, Bhatt, Rajendra Prasad, Ghosh, Aniket, Hembrom, Manoj Emanuel, Hofstetter, Valérie, Parihar, Arvind, Vizzini, Alfredo, Xu, Tai-Min & Zhao, Chang-Lin, 2019, Fungal Biodiversity Profiles 81 - 90, Cryptogamie, Mycologie 20 (5), pp. 57-95 : 78-79

87. Lactarius resinosus X.H. Wang , sp. nov.

( Figs 9 ; 10E ; 15 )

Characterized by slender fruiting bodies, strongly rugose pileus, globose spores with zebroid-winged ornamentation and pileipellis an epithelium with resin-like encrustations on the hyphae beneath the globose cells. Differing from L. castanopsidis and L. corrugatus in having bigger fruiting bodies and dark reddish brown pileus. A long INDEL in the ITS1 region is also characteristic.

TYPUS. — China. Yunnan Prov., Nanjian Co., Lingbao Mt. forest park, 2300 m a.s.l., 4.VII.2012, coll. X.H. Wang, no. 3422 (holo-, KUN [ HKAS 75984 ]!).

MYCOBANK. — MB 829371.

GENBANK. — MK351976 - MK351981 (ITS).

ETYMOLOGY. — Referring to the resin-like encrustations on the hyphae beneath the subglobose cells of pileipellis.

ADDITIONAL SPECIMENS EXAMINED. — China. Yunnan Prov.: Cangyuan Co., Nangunhe nature reserve, 6.VII.2012, coll. R.L. Zhao, no. 2012-117 (KUN[HKAS 85367]); Maguan Co., Gulinqing nature reserve, Piaochang, 22°51’38.2’’N, 104°00’08.6’’E, 1750 m a.s.l., 9.VIII.2017, coll. X.H. Wang, no. 4439 (KUN[HKAS 104242]), no. 4440 (KUN[HKAS 104240]); ibid, 19.X.2017, coll. X.H. Wang, no. 4875 (KUN[HKAS 104241]); Xiping Co., Ailao Mts. nature reserve, Jinshan virgin forest park, 23°56’26’’N, 101°30’09’’E, 2400 m a.s.l., 13.VIII.2017, coll. X.H. Wang, no. 4539 (KUN[HKAS 104239]).

HABIT, HABITAT AND DISTRIBUTION. — 1-4 individuals growing together, under fagaceous trees. Subtropical-tropical Yunnan, China.

DESCRIPTION

Basidiomata

Small to medium-sized.

Pileus

25-45 mm in diam., at first convex with a pointed papilla, becoming plano-convex with a depressed center when mature, margin crenulate; surface yellowish brown, brown, dark brown, sometimes with irregular darker strips, hygrophanous, rugose-granulose all over.

Context

0.5-1 mm thick, cream-flesh colored.

Lamellae

1.5-5 mm broad, decurrent, medium crowded to subdistant (9-15 L/cm), yellowish white, light yellow to grayish yellow, changing to pale brown when bruised, light brown when fully mature.

Stipe

30-50 × 3-6 mm, cylindrical, slightly enlarged downward, nearly hollow, base strigose with reddish brown hairs; surface dry, smooth, dark brown.

Latex

White watery to cream watery,neither discoloring nor staining,mild.

Odor

None or of bugs.

Spore print

Cream-ochre.

Basidiospores

(140/7/6) (6.5) 7.0-7.6-8.5 (9.0) × 6.5-7.2-8.0 (8.5) Μm [Q = 1.00-1.10 (1.14), Q = 1.05 ± 0.03] [holotype (40/2/1) (6.5) 7.0-7.4-8.0 (8.5) × 6.5-7.1-7.5 (8.0) Μm, Q = 1.00- 1.11, Q = 1.05 ± 0.03], globose, subglobose; ornamentation 1.5-2.0 (2.5) Μm high, of ridges variable in size and elongate warts, rarely connected, arranged in a typical spiral or zebroid pattern, with numerous subtransparent (less amyloid) dots in the ridges or warts; plage not amyloid.

Basidia

4-spored, 32-55 × 10-14 Μm, clavate, subfusiform.

Pleuromacrocystidia

Absent.

Hymenophoral pseudocystidia

Rare to common, 3-6 Μm broad, some branching, some enlarging toward apex, with refractive contents.

Lamella edge

Sterile; cheilomacrocystidia abundant, small but easily seen, 17-40 × 4-7 Μm, fusiform, sublanceolate, subcylindrical, with a mucronate or moniliform apex, in the upper part of apex with strongly refractive granular, crystalline or agglomerated contents; marginal cells 10-26 × 5-10 Μm, clavate, cylindrical, rarely capitate.

Pileipellis

A (hymeno)epithelium, 50-70 Μm thick, yellowish brown; cells globose, subglobose, ellipsoid, 10-35 × 10-30 Μm, terminal cells ellipsoid, short largeniform, rarely cylindrical, pyriform or hyphoid, 8-15 (25) × 5-8 Μm; hyphae beneath the pileipellis 5-10 Μm broad, some coated with dark yellowish brown resinous encrustations, not dissolving in 5% KOH.

Stipitipellis

A cutis, 50-60 Μm thick, of closely packed, predominantly longitudinally arranged hyphae; hyphae 4-7 Μm broad, yellowish brown, walls 0.5-0.7 Μm thick, some with dark yellowish brown resinous encrustations.

Lactifers

Very scattered, rarely common in hymenophoral trama, colorless to very pale yellowish brown.

Pileus and stipe trama

With numerous rosettes.

NOTES

The medium-sized, strongly rugose, yellowish brown to dark reddish brown pileus, the watery latex, the globose spores with high zebroid ornamentation and the pileipellis an epithelium with resin-like encrustations on the hyphae underlying the globose cells make this species distinct. Lactarius resinosus X.H. Wang , sp. nov., resembles L. castanopsidis and L. corrugatus in the strongly wrinkled pileus, deeply winged spores and pileipellis an epithelium. Microscopic observations on the type of L. castanopsidis found similar dark-brown hyphae underlying the globose cells in the pileipellis, but it has much smaller fruiting bodies ( Hongo 1979) while L. corrugatus lacks cheilomacrocystidia ( Verbeken & Horak 2000). In L. subg. Russularia , spores with high ridges and wings arranged in a zebroid pattern have also been found in L. qinlingensis X.H. Wang , a species with olivaceous brown areolate-rimose pileus and emergent macrocystidia (Wang 2018) . Thai L. fuscomaculatus Wisitrassameewong & Verbeken and L. atrobrunneus Wisitrassameewong & K.D. Hyde have similar pilei ( Liu et al. 2015; Wisitrassameewong et al. 2015). Both species have low reticulations on the spores. Moreover, L. fuscomaculatus has crowded lamellae and pleuromacrocystidia, while L. atrobrunneus has more distant lamellae and lacks macrocystidia. For more notes, see above under L. exilis .

Figures

FIG. 9. — Original tree generated by Neighbor-Joining (NJ) phylogenetic analysis, rooted with midpoint. NJ analysis was conducted in MEGA X, using bootstrap method (1000 replicates),p-distance as substitution model,transitions and transversions both included,uniform rates among sites,homogeneous pattern among lineages and pairwise deletion for gaps treatment. The bootstrap proportions higher than 70% are indicated above the nodes. New species are in bold. Sample labels are provided in the order of species name, GenBank accession, and geographical origin. For new species, sample numbers with initials of collectors are provided after GenBank accessions.

FIG. 10. — Basidiocarps:A, Lactarius aurantiobrunneus X.H.Wang,sp.nov.(HKAS 101912,holotype);B, L.exilis X.H.Wang,sp.nov.(HKAS 90043);C, L. collybioides X.H. Wang,sp. nov.(HKAS 76002, holotype);D, L. flaviaquosus X.H. Wang,sp. nov.(HKAS 104207,holotype); E, L. resinosus X.H. Wang,sp. nov.(HKAS 104241).

FIG. 15. — Lactarius resinosus X.H. Wang, sp. nov. (all from HKAS 75984-holotype, except B from HKAS 104241): A, basidiospores; B, lamella edge; C, cheilomacrocystidia; D, pileipellis. Scale bars: A, 5 μm; B, 20 μm; C, D, 25 μm.