Cantharellus longisporus Heinem.

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 : 164-169

Cantharellus longisporus Heinem.

( Figs 2 ; 3 )

Cantharellus longisporus Heinem. , Bulletin du Jardin botanique de l’État, Bruxelles 28 (4): 409 (1958).

TYPE MATERIAL. — Holotype. Central Africa , Democratic Republic of Congo (ex Belgium Congo and Zaïre), district forestier central, Binga, gregarious and on the ground in a Gilbertiodendron dewevrei forest, IV.1928, M. Goossens-Fontana 692 ( BR).

MATERIAL EXAMINED. — Republic of the Congo, Sangha department: Nouabalé-Ndoki National Park, Goualougo, 40 km E-SE from Bomassa, 2°12.82’N, 16°31.93’E; 12. I.2012, herb. S. T. Ndolo Ebika 737 ( NEST [ NEST 737], HICPC [ HICPC 294]), S. T. Ndolo Ebika 744 ( NEST 744, HICPC 295).

Democratic Republic of the Congo, oriental province, Tshopo district, Yangambi, Man-and-Biosphere Reserve, rain forest dominated by Gilbertiodendron dewevrei ; 00°47.85’N, 24°29.87’E; alt. 450 m; 26.X.2012; P. Ballings leg.; herb. De Kesel 5210 ( ADK [ ADK 5210], BR [ BR 5020212167440 V]); near Binga, in groups on the soil in Gilbertiodendron dewevrei forest, IV.1928, M. Goossens-Fontana 692 (holo-, BR).

ICONOGRAPHY. — Heinemann (1958: fig. 44; 1959: pl. XVII, fig. 4).

ORIGINAL DIAGNOSIS. — “ Pileus carnosus, centro depressus, lobatus, tomentosus, glabrescens, lilacino-armeniacus. Stipes solidus , lilacinoroseus, deorsum luteus, pallescens. Lamellae latiusculae, distantes, armeniacae, aciem versus aurantiacae, pallescentes, furcatae, leviter intervenulatae. Caro alba, in pileo dilute armeniaca, basi stipite luteola; sapor pungens. Sporae subcylindricae vel leviter arcuatae, 8-10,5 × 3,8-4,8 µm. ”

ORIGINAL DESCRIPTION ( FREELY TRANSLATED FROM FRENCH). — “ Pileus 6-12 cm diam., thick and fleshy, convex with incurved margin, then plane with more or less depressed center; margin lobed, crenulate; surface dull, tomentose, becoming glabrous, pinkish lilac with paler margin, then slightly to distinctly more orange, in the center tinged with pink, vinaceous to brownish.

Stipe 50-90 × 9-25 mm, cylindrical or more irregular, solid inside, light reddish lilac, yellowish toward the base, becoming paler with age, sometimes coalescent at the base, basal mycelium apparent. Hymenophore with gill folds up to 5(7) mm high, rather spaced, at first pinkish orange to bright orange near the cap margin, then light pinkish with orange shades, rather thin, unequal and forked, with some subtle transversal veins. Context firm, white, tinged with yellow near the stipe base, and with pinkish or orange in the pileus. Taste acrid. Smell weakly of C. cibarius when boiling a small piece of the exsiccatum.

Spore print white to pale. Exsiccatum brownish grey to ochraceous brown, stipe concolorous or slightly more yellow, hymenophore reddish brown, context ochraceous to ferrugineous. Spores 8-10.5 × 3.8-4.8 µm, narrowly ellipsoid to subcylindrical or weakly curved, presenting often a slight depression at the adaxial side, thin-walled, with a small apiculus. Basidia measuring for ex. 65 × 7.5 µm, four-spored. Pileipellis composed of slender, cylindrical hyphae, measuring 4-11 µm diam., thin-walled and slightly yellowish. Clamp connections present.”

HABITAT. — Dense rain forests of Central Africa, under ECM Gilbertiodendron dewevrei , either in monospecific stands or mixed with ECM Julbernardia seretii and Paramacrolobium coeruleum (Taub.) J.Léonard.

DESCRIPTION

Basidiomata

Large, very firm and fleshy, frequently with few individuals fused together in the lower stipe ( Fig. 2 A-D), up to 100 mm high and between 85-130 mm wide when fully expanded.

Pileus

Plano-concave to slightly depressed ( Fig. 2A ), in age often becoming funnel-shaped; the margin first inrolled ( Fig. 2A ), becoming strongly lobed, wavy and straight at maturity ( Fig. 2B, D ); pileus surface azonate, when young entirely dark greyish violet to purple brown (10-11F2-4) from appressed, minute, dark squamules on the orange-yellow background of the surface underneath ( Fig. 2A ), remaining so with age in the pileus center, squamules towards the margin gradually more spaced, losing their dark color at the margin fading to yellowish orange or orange-yellow (4A4-6) ( Fig. 2B, D ).

Hymenophore

Deeply decurrent ( Fig. 2C ), 3-5(-7) mm high, when young composed of spaced, well-differentiated gill folds (4-6 long ones per cm at pileus margin) separated by smooth interstitial spaces and intermixed with up to four lengths of short lamellulae near the pileus margin, not forked, except near the very pileus margin; the interstitial spaces becoming with age gradually more veined over their entire surface with the veins descending on the sides of the gill folds, pale yellowish (4A2-3), brighter and more orange (4A4-6) near the pileus margin, hardly changing when bruised.

Stipe

45-90 mm high, thick and fleshy, up to 20 mm diam., cylindrical or widening upwards, sometimes splitting upwards, thereby forming more than one cap ( Fig. 2C ), white to yellowish (4A2) toward the base, marked with violet brown (10-11E2-5) in the upper part from minute squamules.

Context

Fibrous, whitish, clearly yellow in the base of the stipe and just beneath the pileipellis, unchanging when cut or injured ( Fig. 2E ).

Taste

Distinctly peppery.

Odour

Weak, not striking.

Spore print

Off-white on gill folds, pale yellowish in deposit (4A2).

Spores ( Fig. 3A )

Narrowly ellipsoid to elongate, 7.7- 9.1 -10.5(-10.7) × 3.4- 3.9 -4.5(-4.5) µm {N=25}, Q = 1.96- 2.33 -2.7(-2.75), hyaline, thin-walled, smooth.

Basidia ( Fig. 3B )

51- 64 -72 × 8.5- 10 -11.5 µm {N=7}, 4-6-spored.

Subhymenium

Subfilamentous, composed of rather narrow, more or less cylindrical cells.

Pileipellis ( Fig. 3C )

Composed of thin-walled, elongated elements, sometimes slightly wider near the septa, 6.5-10 µm diam.; the terminal cell up to 95 µm long, predominantly subcylindrical, but frequently slightly constricted or somewhat narrowing at the tip.

Clamp connections

Conspicuous on hyphae of all tissues.

NOTES

Cantharellus longisporus has been variously misinterpreted in the past (e.g. Morris 1987; Ryvarden et al. 1994) most likely due to the remarkably long basidiospores – the apparently most prominent feature, reflected in its name – which are also found in a few other African Cantharellus species, all of which share thin-walled hyphal extremities at the pileus surface, although mostly lacking clamp connections.

Field notes for the new collections of C. longisporus confirm the distinctly acrid taste mentioned in the original description. This suggests that taste should consistently be recorded when collecting Cantharellus in the field as it is a potentially interesting character to distinguish between different Cantharellus from this habitat. Another character from the original description is the presence of weak anastomosing veins in between the yellow-orange gill folds in the more mature stages. These veins are principally running down as vertical “ribs” on the lower gill sides.

However, we did not observe the appearance of pinkishlilac colors that Heinemann mentioned for the older stages of the hymenophore.

The extremely variable pileus coloration, which was described (and illustrated) as a mixture of pink, lilac, orange, brown and vinaceous ( Heinemann 1958, 1959), made it indeed difficult to decide whether or not specimens with at least one of the aforementioned colors and similar microscopy, belonged to the same species or not. As a consequence, Buyck et al. (2012) published two new and microscopically similar subspecies for C. longisporus from different habitats in Madagascar. One of these new subspecies, C. longisporus subsp. littoralis Buyck & Randrianjohany , is associated with coastal Uapaca species on the sandy soils of Madagascar’s east coast, while the other one, C. longisporus subsp. isaloensis Buyck & Eyssart. , was collected in Uapaca bojeri Baill. – Sarcolaenaceae woodland on the lateritic soils of the Central Plateau.

We were unable to obtain sequences from these more recent Central African specimens of C. longisporus , as well as for its Malagasy subsp. isaloensis , but we did obtain most genes for subsp. littoralis thanks to more recent collections. The latter subspecies actually corresponds to what Heim (1936) originally described as C. cyanoxanthus nom. inval., a name later validated – but differently interpreted – for a Central African chanterelle by Heinemann (1958). Even in the absence of good sequence data for the Central African C. longisporus , the distinctive morphology of this species revealed here makes it completely different from both Malagasy subspecies. Consequently, these Malagasy subspecies are recombined below as new species as they undoubtedly represent independent, Malagasy Cantharellus lineages.

Figures

FIG. 2. — Cantharellus longisporus Heinem.: A, young specimens ([HICPC294] with inserted original watercolor of holotype from Heinemann 1959); B, D, details of the pileus [HICPC295]; C, cylindrical or widening upwards stipe with hymenophore; E, detail of context. Photos: S. T. Ndolo Ebika & P. Ballings.

FIG. 3. — Cantharellus longisporus Heinem. (HICPC294): A, spores; B, basidia and basidiola; C, hyphal endings of the pileipellis.Scale bar: 10 µm, but only 5 µm for spores. Drawings: B. Buyck.