Cantharellus violaceoflavescens De Kesel, Guelly, L.A.Parra & Buyck, 2020

Buyck, Bart, Ndolo, Sydney T., Ebika, Kesel, André De & Hofstetter, Valérie, 2020, Tropical African Cantharellus Adans.: Fr. (Hydnaceae, Cantharellales) with lilac-purplish tinges revisited, Cryptogamie, Mycologie 20 (10), pp. 161-177 : 172-173

publication ID	https://doi.org/ 10.5252/cryptogamie-mycologie2020v41a10
persistent identifier	https://treatment.plazi.org/id/03C28781-A356-D306-322B-64F5DE0CFACA
treatment provided by	Felipe
scientific name	Cantharellus violaceoflavescens De Kesel, Guelly, L.A.Parra & Buyck
status	sp. nov.

Treatment

Cantharellus violaceoflavescens De Kesel, Guelly, L.A.Parra & Buyck , sp. nov.

( Figs 6 View FIG ; 7 View FIG )

MYCOBANK. — MB 835036.

DIAGNOSIS. — Medium-sized species with violet-tinged and minutely squamulose pileus and stipe, with pure white hymenophore composed of well-developed, forking gill folds, entirely and strongly yellowing with age. Spores ellipsoid, (6.2)6.9- 7.38 -7.8(8.3) × (4.1)4.3- 4.58 -4.9(5.2) µm, Q = (1.3)1.5- 1.61 -1.7(1.8). Clamp connections abundant in all tissues. In gallery forests with Berlinia grandiflora .

TYPE MATERIAL. — Holotype. Togo, Plateau province, Ola, galerie Okpa-Fou, on the ground in a semi-deciduous gallery forest dominated by Berlinia grandiflora and Uapaca guineensis ; 07°33.44’N, 0°52.35’E; alt. 700 m; 12. V.2010; A. De Kesel leg.; De Kesel 4790 (holo-, BR [ BR 5020167050163]).

ETYMOLOGY. — Violaceoflavescens, a combination of the latin words violaceo (meaning color violet) and flavescens (meaning becoming yellow).

ADDITIONAL STUDIED AND SEQUENCED MATERIAL. — Togo, Plateau province, Ola, galerie Okpa-Fou, on the ground in a semi-deciduous gallery forest dominated by Berlinia grandiflora and Uapaca guineensis ; 07°33.44’N, 0°52.35’E; alt. 700 m; 12.V.2010, A. De Kesel leg.; De Kesel 4791 (para-, ADK[ADK4791], BR[BR 5020167046128]). Ibid., gallery Gonobé, on the ground in semi-deciduous gallery forest dominated by Berlinia grandiflora and Uapaca guineensis ; 07°32.73’N, 0°55.06’E; alt. 680 m; 17.V.2010; A. De Kesel leg.; De Kesel 4829 (ADK[ADK4829], BR[BR5020167049150]). Ibid., gallery Néoubengnoua, on the ground in semi-deciduous gallery forest dominated by Uapaca guineensis ; 07°51.55’N, 0°47.68’E; alt. 670 m; 28.VI.2011; A. De Kesel leg.; De Kesel 4963 (ADK[ADK4963], BR[BR5020184227653]). Ibid, Béna-Ola, gallery Néhou-Begnoi, gallery forest dominated by Berlinia grandiflora and Uapaca heudelotii ; 07°33.51’N, 0°52.33’E; alt. 690 m; 7.VII.2007; A. De Kesel leg.; De Kesel 4187 (ADK[ADK4187], BR[BR5020163641020]). Ibid., gallery forest dominated by Berlinia grandiflora ; 07°33.24’N, 0°53.517’E; alt. 650 m; 10.VII.2007, A. De Kesel leg.; De Kesel 4273 (ADK[ADK4273], BR[BR5020158469684]). Ibid., on the ground in gallery forest dominated by Berlinia grandiflora and Uapaca guineensis ; 07°31.73’N, 0°54.96’E; alt. 780 m; 15.V.2010; A. De Kesel leg.; De Kesel 4815 (ADK[ADK4815], BR[BR5020167047132]). Ibid., Imoussa, gallery Iklowou, on the ground in semi-deciduous gallery forest dominated by Berlinia grandiflora ; 07°33.36’N, 0°56.54’E; alt. 740 m; 13.V.2010; A. De Kesel; De Kesel 4802 (ADK[ADK4802], BR[BR5020167051177]).

HABITAT. — Gallery forests with Berlinia grandiflora , sometimes mixed with Uapaca guineensis .

DESCRIPTION

Basidiomata

Solitary or in groups of two to four ( Fig. 6A, B, E View FIG ).

Pileus

40-60 mm diam., thin-fleshed, broadly depressed to infundibuliform when mature; margin incurved, sharp, straight or slightly upturned, striate and undulating at maturity;

surface finely tomentose-fibrillose in the center, disrupting into very minute squamules towards the margin, at first very dark greyish violet (14-16DEF6-8, 17F5) and remaining so in the center ( Fig. 6A, B View FIG ), outside the center quickly a paler violet to greyish violet (17DEF5-7), at maturity often maintaining a narrow, whitish marginal edge, developing irregular, whitish patches outside the pileus center and quickly staining light yellow (1A2, 3A1-3), also when bruised, with age entirely becoming yellow (4A2-3) from the margin inwards.

Hymenophore

Deeply decurrent and well-delimited from the sterile stipe surface, composed of arcuate gill folds, moderately spaced (3-6 per cm near pileus margin), often forked near the margin ( Fig. 6E View FIG ), gill sides developing thick vertical ribs or veins, occasional transversal connections and anastomoses usually rare and remaining rather low, never becoming reticulate-alveolar in aspect, of a contrasting pure white at first ( Fig. 6E View FIG ), sometimes with local purplish-violet tinges near the cap margin, rapidly bruising yellowish, with age becoming entirely off-white to pale yellow (3A2-3) ( Fig. 6 View FIG C-D).

Stipe

Slender, 40-60 × 4-6(7) mm, rarely straight, subcylindrical or tapering downward, smooth or sparsely beset with minute dark violet squamules, white near the base, whitish to greyish violet (17AB2) elsewhere, bruising yellow particularly near the very base, with time becoming entirely pale yellow to greyish yellow (4AB2-3), solid or becoming fistulose within.

Context

Thin, whitish, unchanged when cut, with age yellowing just beneath pileus and stipe surface.

Taste

Peppery, moderately strong after 15 seconds.

Odour

Weak, insignificant.

Spore print

Not obtained.

Spores ( Fig. 7A View FIG )

Ellipsoid, (6.2)6.9- 7.38 -7.8(8.3) × (4.1)4.3- 4.58 -4.9(5.2) µm, Q = (1.3)1.5- 1.61 -1.7(1.8), smooth, hyaline.

Basidia ( Fig. 7B View FIG )

Very long and slender, (65-)80-110 × 7-9 µm, (5-)6-spored.

Cystidia View in CoL

Absent.

Subhymenium

Filamentous, composed of long and slender, cylindrical cells.

Pileipellis ( Fig. 7C View FIG )

Composed of thin-walled elements, terminal elements subcylindrical to clavate, 8-12 µm diam., frequently with a slightly thickened and refringent wall.

Clamp connections

Rather small, but on hyphae of all tissues.

NOTES

Cantharellus violaceoflavescens De Kesel, Guelly, L.A.Parra & Buyck , sp. nov., is still only known from a few sites around the type locality. The description is based on the holotype, but spore measurements on a few other collections result in very similar values as for the holotype. This confirms that this species differs from other known chanterelles with more or less similar coloration in the size and form of its spores:

ADK4790 (6.2)6.9- 7.38 -7.8(8.3) × (4.1)4.3- 4.58 -4.9(5.2) µm, Q = (1.3)1.5- 1.61 -1.7(1.8);

ADK4802 (6.4)6.7- 7.18 -7.6(8.5)× (3.7)4.1- 4.29 -4.5(4.8) µm, Q = (1.5)1.6- 1.68 -1.8(1.9);

ADK4815 (6.2)6.7- 7.04 -7.4(7.9) ×3.9)4.2- 4.54 -4.8(5.0) µm, Q = (1.4)1.5- 1.56 -1.7(1.8).

Cantharellus violaceoflavescens De Kesel, Guelly, L.A.Parra & Buyck , sp. nov., is unmistakable in the field because of the contrast between the pure white hymenophore with low interstitial anastomosing veins and the dark violaceous, squamulose surfaces of stipe and pileus of young specimens, followed by a spectacular yellowing with age. The only more or less similar species so far is the here newly combined Malagasy C. littoralis (Buyck & Randrianjohany) Buyck , comb. et stat. nov., which differs in its much more fleshy basidiomata, the better developed gill folds without interstitial venation, and the weaker yellowing with age. Cantharellus conspicuus , described from miombo woodland in Zimbabwe, is much smaller, shows a strongly squamulose surface of pileus and stipe, as well as stronger interstitial venation between gill folds.