Lactarius lanceolatus O.K. Mill G. Laursen
Creators: name: Jacob Heilmann-Clausen
name: Annemieke Verbeken
name: Jan Vesterholt
Publisher: name: Danish Mycological Society
Year: 1998
Subjects: Biodiversity
Taxonomy
Fungi
Basidiomycota
Agaricomycetes
Russulales
Russulaceae
Lactarius
Lactarius lanceolatus

description: Lactarius lanceolatus O.K. Mill G. Laursen  
Lactarius lanceolatus O.K. Mill G. Laursen, 1973: 43. Holotype: Alaska, Beaufort Lagoon (VPI).  
A medium-sized Lactarius with white milk; and orange-brownish colours; very similar to L. aurantiacus but occurring in alpine and arctic habitats with dwarf Salix.  
DESCRIPTION: Cap 25-55 mm, convex to applanate with a decurved or inrolled margin, later depressed With expanded margin, sometimes with a small umbo or papilla, margin often finely crenulate; surface smooth, dry to sticky or glossy, often becoming mat and areolate-rimose in a concentric pattern, margin at first pruinose, dark brick to brick or orange-brown, darkest in the centre. Gills adnate to slightly decurrent, medium crowded, pinkish buff, later clay-pink to Isabella-coloured. Stem 20-30 x 5-11 mm, cylindric to subclavate; surface smooth, dry, faintly pruinose when young, clay-buff to cinnamon. Flesh fragile, soon hollow in the stem, pale cream to pale pinkish buff, outer part coloured like surface: smell faint or like L. quietus; taste mild or becoming slightly bitter. Milk White or watery white, unchanging; taste mild or slightly astringent. Spore deposit whitish.  
Spores 72-11.3 x 5.6-8.4 pm, av. 8.0-9.8 x 6.5-7.4 pm, subglobose to ellipsoid, Q = 1.05- 1.55, av. 1.21-138; ornamentation 0.3-0.9 pm high, of fine elongate warts, joined by fine lines and low ridges to form an incomplete reticulum, isolated warts numerous; plage inamyloid or with an amyloid distal spot. Basidia 35-60 x 10-13 pm, subclavate, 4-spored. Pleuromacrocystidia scattered to rather abundant, 50-135 x 6.5-10.5(-12) pm, narrowly fusiform to conical, often flexuose to moniliform, apex acute, subacute or mucronate. Gill edge heterogeneous; cheilomacrocystidia numerous, 20-60 x 4-10 pm, fusiform or conical, apex acute or moniliform. Pileipellis an intricate (ixo)trichoderm; terminal elements 15-50 x 2-5 pm, cylindric; subpellis very compact, of darker, slightly swollen hyphae, about 6 um broad.  
ECQLOGY AND DISTRIBUTION: In Europe L. lanceolatus is only known from the northernmost part of Fennoscandia. It associates with dwarf Salix and is widely distributed in Greenland, northern North America and probably Siberia.  
DISCUSSION: Lactarius lanceolatus is similar to, or maybe even conspecific with L. aurantiacus. Lactarius lanceolatus is often somewhat darker and more reddish than L. aurantiacus, and the cracking of the cap is usually not seen in L. aurantiacus. These differences may be caused by the extreme environmental conditions. Lactarius lanceolatus often has longer macrocystidia and larger, more faintly ornamented spores than L. aurantiacus, but intermediates occur. For further discussion, see Gulden et al. (1988).
description: Published as part of Jacob Heilmann-Clausen, Annemieke Verbeken & Jan Vesterholt, 1998, The Genus Lactarius, Copenhagen :Danish Mycological Society on page 180