Cantharellus densilamellatus Buyck & V. Hofst.

Buyck, Bart, W. Henkel, Terry & Hofstetter, Valerie, 2019, Epitypification of the Central African Cantharellusdensifolius and C. luteopunctatus allows for the recognition of two additional species, MycoKeys 49, pp. 49-72 : 49

Cantharellus densilamellatus Buyck & V. Hofst. sp. nov. Figs 9, 10

Diagnosis.

Cantharellus densilamellatus resembles C. densifolius in its overall yellowish to orange-brown color, but differs in its thinner and comparatively well-developed gill folds with less blunt edges, smaller size, nearly thin-walled, less undulate hyphal extremities at the pileus surface, more elongate basidiospores, and its seasonal woodland habitat.

Gene sequences ex-holotype.

JX193014 (published in Buyck et al. 2014).

Etymology.

" densilamellatus "; referring to the relatively close spacing of the gill folds.

Holotype.

TANZANIA. Msanga village, in very degraded woodland with Brachystegia , 24 April 1998, Buyck 98.013 (PC0084126). MycoBank MBT 828893.

Description.

Basidiomata small to medium-sized. Pileus up to 60 mm diam., first centrally depressed and with a downturned margin, then becoming more depressed as the margin spreads out, fleshy in the center, but increasingly thin fleshed toward the margin and there often striate or radially splitting; margin regular to slightly wavy-lobed; surface dry, with a pale to dark brown to reddish brown tomentum (5DEF6-8) contiguous over disc, toward margin tomentum separating concentrically into a pale yellowish cream (3A2-3) areolate pattern. Hymenophore composed of thin, well-developed gill folds, 2-3 mm high, densely spaced (> 10/cm) but not crowded, forking, not anastomosing, often splitting transversely through their entire height, uniformly pale yellow (3A4), brighter than the pileus margin and stipe. Stipe central, up to 40 mm long, 6-11 mm wide, subcylindrical to slightly wider near the base, rapidly elongating before the pileus margin starts to spread, concolorous with the pileus margin, distinctly finely squamulose over apical portion, compact in section. Context off-white to pale cream, weakly yellowing. Odor fruity. Taste mild. Spore print off-white to very pale yellowish.

Basidiospores narrowly ellipsoid to almost elongate, often reniform or peanut shaped, 6.7 –7.05–7.4(– 7.9) × (3.3 –)3.4–3.65–3.9(– 4.0) µm, Q = (1.7 –)1.8–1.94–2.1(– 2.3), smooth. Basidia rather short, 35 –50(– 58) × 6-7 µm, (4 –)5– 6-spored; basidioles mostly clavate. Cystidia none. Subhymenium pseudoparenchymatous, composed of irregular, slightly inflated cells. Pileipellis a cutis of interwoven hyphal extremities forming slender chains of subcylindrical cells, these quite regular in outline, with thin to very slightly thickened and refringent walls; terminal cells (25 –)30–45(– 65) × (3 –)4– 7 µm, subcylindrical or sometimes very slightly inflated in the lower or middle portion, obtusely rounded at the tip or slightly constricted subapically. Clamp connections absent.

Discussion.

Cantharellus densifolius has long been the only available name for yellowish brown, clampless chanterelles in Africa with a squamulose pileus and crowded gill folds. Indeed, the holotype collection of C. densilamellatus reported here was initially identified as C. densifolius in Buyck et al. (2000) and, in the absence of any reliable concept for Heinemann’s species, was even maintained as C. densifolius in the multigene Cantharellus phylogeny of Buyck et al. (2014). Although more than one woodland species might have been referred to as ' C. densifolius ', C. densilamellatus as described here is undoubtedly one of the more common and widespread inhabitants of the Zambezian miombo woodlands. It differs from the true C. densifolius not only in its habitat preference, but also in its more elongated basidiospores, which are very similar to those of C. tomentosus Eyssart. & Buyck (another, but much less common, woodland species with crowded gills and much darker pileus surface and hymenophore - see Buyck 1994 [as ‘nyarympu’, its Kirundi vernacular name] and Buyck et al. 2000). Cantharellus densilamellatus further differs micromorphologically from C. densifolius in its more regular, less undulate and thinner-walled hyphal extremities of the pileus surface (Fig. 10). While the phylogenetic analysis presented here (Fig. 1) shows a close relationship of C. densilamellatus with C. luteopunctatus , the latter species differs in its pinkish, erect squamae, bright yellow pileus color, and initially white and strongly anastomosing gill folds.