Search on : Taxa descriptions

 


 
 Add this item to the list   820335 Original description
   
Remarks (public):Koziak, A.T.E., F. Chavarria, J. Diaz, M. Garcia, D.H. Janzen and R.G. Thorn. 2007. Costa Rican species of Nematoctonus (anamorphic Pleurotaceae). Can. J. Bot 85 (8): 749-761. 
Description type:Original description 
Description:Diagnosis. A species of Hohenbuehelia with dimidiate fruiting bodies, distinguished from similar species by its glabrous, lubricous pileus, pallid colour, and its diagnostic ITS-LSU sequences, ALV9753.

Basidiocarps gregarious to imbricate, dimidiate to orbicular, laterally or dorsally attached without stipe or pseudostipe, 2.0–3.2 cm wide × 1.4–2.5 cm deep. Margins acute, plane, very faintly translucent-striate. Upper surface appearing moist, shiny, off-white (4½A1½), finely white-tomentose towards base. Lamellae radiating from point of attachment, narrow, close, white to off-white (4AB1½). Basidiospores 7.0–8.2 × 3.1–3.7 µm (on average, 7.6 × 3.4 µm) (n = 32), Q 2.08–2.42 (on average, 2.25), Vm = 47 µm3, cylindrical in front view, allantoid in side view, with dull, granular content or with one or more oily drops; inamyloid, smooth. Basidia 19–24 × 5.2–6.8 µm, four-spored, sometimes two-spored, clavate to subcylindraceous, sterigmata up to 7 µm long. Hymenophoral trama irregular, made up of gelatinized hyphae up to 9.5 μm wide, hyaline in L4, yellow in Melzer’s. Cheilometuloids isolated or in groups along the lamellar edge, 30–46 × 11–14 μm, subfusoid, generally with a narrow base, mostly with a lanceolate apical part and partly covered with refringent, yellow or whitish, crystalline granules. Mounted in Melzer’s they react pale reddish (dextrinoid reaction), while in cresyl blue the wall stains vinaceous red (metachromatic reaction). Cheilocystidia of the gloeosphex type (Thorn & Barron 1986), in most cases with one or two swellings protruding from the apical portion, rarely capped with a tiny, vanishing drop of mucus, 13–17 × 4.9–9.4 μm, with a neck and capitulum of 3.9–7.8 × 1.9–2.1 μm. Pleurometuloids 55–63 × 14–18 µm, similar to cheilometuloids. Pileipellis consisting of an ixocutis of variously intertwined, slightly gelatinized, filamentous, smooth hyphae, 3–9.5 μm wide, yellow in Melzer’s, with a light brown intracellular pigment, with undifferentiated terminal elements. Gelatinous zone ca. 400 μm thick, hyphae 1.5–4.5 μm wide. Underlying pileus trama having a thickness varying from 50 to 450 μm, made up of hyphae up to 9 μm wide and with walls up to 1 μm thick. Clamp connections present everywhere.
Cultural characters — on water agar with nematodes, with assimilative and fertile hyphae hyaline, clamped, 1.6–2.4 m in diameter; fertile hyphae producing predominantly terminal predatory adhesive knobs, and conidia holoblastically from tapering denticles up to 2.5 m tall; adhesive knobs occasionally intercalary from short cylindric branches, hour-glass secretory processes 3.2–9.6 m long, base 1.6–3.2 m wide, tip 0.8–3.2 m wide, surrounded by a mucoid drop 4.0–7.2 × 2.4–5.6 m; conidia cylindric to allantoid, aseptate, (5.6–)7.2–13.6(–15.6) × (1.6–)2.4–4.0(–6.4) m, Q = (2.1–)2.4–3.5(–4.0); conidia germinating with a tapering germ tube 5–25 m long, with an hour-glass secretory process 3.2–5.6 m long by 1.6–3.2 m, surrounded by a subglobose mucoid droplet 3–8 × 3–6.5 m. Previously described and illustrated by Koziak et al. (2007) as Nematoctonus robustus (in part; their Figs. 15–17), who noted that isolates that proved to be this species were unusual in producing conidia that germinated on water agar with nematodes, a feature not seen in other isolates nor previously described for N. robustus.
 
Taxon name: