Lentinus sajor-caju (Fr.) Fr., Epicrisis Systematis Mycologici: 393 (1838)

Facesoffungi number: FoF 3142

Pileus 3–9 cm diam., coriaceous drying hard and rigid, soft, convex with a deeply umbilicate centre then cyathiform to infundiliform, or eccentric and flabelliform, surface very variable in colour, cream colour, pale ochraceous, more or less fuliginous, or umbrinous, dry glabrous and smooth or sometimes with small, appressed, darker squamules especially towards the centre, often finely radially striate, rimose in old specimens; margin initially incurved to involute soon straight, very thin, smooth, undulating and lobed. Lamellae deeply decurrent, not furcate, whitish, concolorous with the pileus, or becoming darker towards the edge, often darkening on drying, narrow to sub-linear, 0.5–3 mm broad, densely crowded, with lamellulae of 4–6 lengths; edge entire or finely denticulate. Stipe central, eccentric or lateral, short, 0.5–3 × 0.5–1.5 cm, cylindric with an abrupt base, solid; surface concolorous with the pileus, at times blackening especially towards the base. Annulus present, attached towards stipe apex, firm, white to fulvous, either well formed, slight or commonly weathered away. Context up to 8 mm thick at the centre but very thin over the hymenophore, tough and pliant drying hard and horny, white, consisting of a very tightly woven, dimitic hyphal system with skeleton-ligative hyphae. Generative hyphae 2–5 μm diam. not inflated, very thin-walled, frequently branching with clamp connections. Skeleto-ligative hyphae dominant, 2–8 μm diam., hyaline or pale yellowish, with a thick wall of 3 μm and often a very narrow lumen, comprising a skeletal element, 100–400 μm long, bearing two to several tapering ligative branches, up to 400 μm long, which are themselves dichotomously divided, sometimes the branches are very short, numerous and nodulose to produce a coralloid appearance. Basidiospores 5–9 × 1.5–2.5 μm, Q =3.23, narrowly cylindric, often curved, hyaline, thin-walled, with few contents. Basidia 15–20 × 3.5–5 μm, very narrow, clavate, cylindric, bearing 4 sterigmata. Lamella-edge a broad sterile zone, with scattered or clustered Cheilocystidia and numerous, emergent skeleto-ligative branches. Cheilocystidia 20–25 × 4–6 μm, clavate, often sinuous or nodulose, hyaline, thin-walled. Hyphal pegs abundant, 50–100 × 20–40 μm, truncate cylindric, consisting of fascicles of up to 50 narrow hyaline hyphae, extending up to 80 μm beyond the basidia. Hymenophoral trama irregular, hyaline, broad, of radiate construction, very compactly interwoven with few interhyphal spaces, and ligative branches frequently penetrating the hymenium. Subhymenial layer often indefinite or indistinct, becoming pseudoparanchymatous when well developed. Pileipellis an epicutis, 15–20 μm thick, of agglutinated, radiating generative hyphae, often with a brown encrustation and sometimes a brown membrane pigment. Smell mushroomy and an excellent edible species.

Habit, habitat and distribution: as a cluster, usually on dead or decaying wood, May to August. Our collection was collected on a decaying wood near Peradeniya Royal Botanic Gardens.

Specimens examined: SRI LANKA, Kandy District, near Peradeniya Royal Botanic Gardens, 23 June 2012, Samantha C. Karunarathna (MFLU 12-1478). GenBank number ITS:KY649463.

Notes: Lentinus sajor-caju is one of the most common macrofungi of the palaeotropical forests, with the distribution extending from equatorial and southern Africa, although less frequent in West Africa to throughout south-east Asia and down to the north-east corner of Australia. This is the first report of L. sajor-caju with the molecular phylogenetic confirmation from Sri Lanka Pegler (1983) has previously reported it.

Phylogenetic relationships inferred from maximum parsimony analysis of ITS-rDNA sequences of 36 taxa. The percentages of replicate trees in which the associated taxa clustered together in the bootstrap test (1,000 replicates) are shown next to the branches. The tree is drawn to scale, with branch lengths in the same units as those of the evolutionary distances used to infer the phylogenetic tree. The new Sri Lankan records: Lentinus sajor-caju, having GenBank number KY649463 and herbarium number MFLU 12-1478; Lentinus squarrosulus, having GenBank number KY649464 and herbarium number MFLU 12-1228; Lentinus velutinus, having GenBank number KY649465 and herbarium number MFLU 12-1123 are shown in bold and blue. The topology is rooted with Panus lecomtei. Evolutionary analysis was conducted in PAUP 4.0b 10.


Basidiocarps of Lentinus sajor-caju in the field (MFLU 12-1478).

Lentinus sajor-caju (MFLU 12-1478) a Cheilocystidia. b Basidiospores. c Basidia. d Skeletal hyphae. e Generative hyphae. Scale bars: a, c = 20 µm, b, d, e = 10 µm.