Pleonectria zanthoxyli (Peck) Hirooka, Rossman & P. Chaverri, comb. nov. (as 'xanthoxyli). MycoBank MB519722. Figs 146-148.
Basionym. Valsa xanthoxyli Peck, Annual Rep. New York State Mus. 31. 49. 1879.
[equivalent to] Pseudovalsa xanthoxyli (Peck) Sacc., Syll. Fung. 2. 137. 1883
[equivalent to] Fenestella xanthoxyli (Peck) Sacc., Syll. Fung. 2. 332. 1883
[equivalent to] Thyronectria xanthoxyli (Peck) Ellis & Everh., North Amer. Pyrenomyc. p. 92. 1892
[equivalent to] Nectria xanthoxyli (Peck) Rossman, Mem. New York Bot. Gard. 49. 264. 1989.
Anamorph: zythiostroma-like.
Teleomorph on natural substrata: Teleomorph on natural substrata. Mycelium not visible around ascomata or on host. Stromata immersed in substrate, up to 1.5 mm high and 2.5 mm diam, greenish yellow, KOH- and LA-, cells forming prosenchymatous. Ascomata immersed in stromata, scattered to aggregated in groups of 3-12, subglobose to globose, 200-400 [micro]m high x 210-410 [micro]m diam, constricted at black papilla, KOH- and LA-, covered by abundant yellowish green to dark green scurf. Ascomatal surface cells forming textura globulosa, sometimes including bright yellow scurf, 5-10 [micro]m diam, with pigmented, irregularly ca. 1.0 [micro]m thick walls. Ascomatal wall 20-40 [micro]m thick, of two regions. outer region 10-30 [micro]m thick, intergrading with stroma, cells forming textura globuosa to t. angularis, walls slightly pigmented, about 1.0 [micro]m thick; inner region 5-10 [micro]m thick, of elongate, thin-walled, hyaline cells, forming textura prismatica. Asci clavate, 60-85 x 15-20 [micro]m, with inconspicuous ring at apex, 8-spored, ascospores biseriate above, uniseriate below, or sometimes uniseriate throughout. Ascospores hyaline, narrowly ellipsoidal to allantoid, muriform, with 5-7 transverse septa and one longitudinal septum, (17.8-)19.423.6(-26.6) x (5.4-)7.0-8.8(-9.7) [micro]m (n = 133), smooth.
Anamorph in culture: After 7 d at 25[degrees]C, colonies 54-85 mm (average 67 mm) diam. Colony surface cottony with aerial mycelium, whitish yellow; aerial mycelium developed, rarely small, yellow, sporodochial conidial masses produced after 2 wk; reverse whitish yellow to slightly glaucous in centre and white at margin. Odour on PDA slightly fruity. Sporulation on SNA from lateral phialidic pegs abundant, enteroblastic, monophialidic, ellipsoidal, slightly tapering toward tip or flask-shaped, 2.7-6.5 [micro]m long, 1.4-2.6 [micro]m wide at base. Conidiophores rarely formed, unbranched, sometimes verticillate, 1(-2)-branched, becoming loosely to moderately densely branched, 9.6-40.9 [micro]m long, 1.3-4.3 [micro]m wide at base. Conidiogenous cells enteroblastic, monophialidic, cylindrical, slightly tapering toward tip or narrowly flask-shaped, 3.3-11.9 [micro]m long, 1.1-3.1 [micro]m wide at base. Young conidia formed from monophialides on aerial, submerged, or repent hyphae, formed abundantly on slimy heads, ellipsoidal, to cylindrical, rarely allantoid, hyaline, smooth, curved, rounded at both ends, non-septate, (3.5-)4.2-5.2(-6.4) x (1.1-)1.4-2.0(-2.5) [micro]m (n = 150). Mature conidia swollen, 0-septate, ellipsoidal to oblong with irregularly swollen at both ends or clavate, hyaline, smooth, straight or slightly curved, (7.1-)8.0-10.0(-12.1) x (2.0-)2.3-3.1(-3.7) [micro]m (n = 150). Pycnidia produced on SNA and PDA after 1-2 month (A.R. 4280). Chlamydospores and ascomata not produced in culture.
Habitat: On dead woody substrata including Crataegus sp., Peraphyllum ramosissimum, Zanthoxylum americanum, Zanthoxylum sp.
Distribution: Europe (France), North America (Canada, USA), South America (Brazil).
Lectotype of Valsa xanthoxyli designated herein: USA, New York, West Troy,...