Pyrenomycetes Species Page

Xenolophium pachythele

Large clustered ascomata
(Berk. & Broome) Huhndorf, Mycologia 85(3): 497 (1993)
Sphaeria pachythele Berk. & Broome
Pleosporomycetidae, Incertae sedis
Figure from SMH4022
Complete Description
Ascomata globose, large, (850)950-1350(2000) _m diameter, 950-1500(2300) _m high, scattered to clustered, numerous, erumpent superficial, with bases immersed in the substrate, papillate, stroma absent; surface roughened, coarsely warted. Wall of textura angularis-globosa in surface view; in longitudinal section approx. 100 _m thick, two-layered, composed of polygonal to elongate, small, compressed, pseudoparenchymatic cells, with external heavily melanized crust, outer cell layers with heavy to light melanization intergrading irregularly into the inner layers of hyaline to pale brown cells, individual cell boundaries obscured in both layers. Papilla short, wide, longitudinally compressed, (400)550-950 _m long, 300-600(1000) _m wide, 200-350(600) _m high; wall composed of small, heavily melanized cells; ostiole slit-like, 25-50 _m wide, with periphyses. Pseudoparaphyses 1.0-1.5 _m wide, numerous, trabeculate, with gelatinous coating. Asci elongate clavate, 80-130 x 5-7.5 _m, long-stalked (stalk 40-60 _m long), numerous, basal and lateral, completely lining the peripheral wall of the centrum, thin-walled, bitunicate, dehiscence unknown; apex rounded, apical chamber present, without ring; with eight ascospores, biseriate above-uniseriate below. Ascospores fusoid, biconoid, (15.5)16.5-22 x 3.0-4.5 _m, straight to slightly curved, light to dark brown, paler pigmented end cells, smooth, with diffuse sheath around entire spore, without appendages, one to three-septate, with deep constriction at mid-septum only, breaking into part-spores, primary septum median, secondary septa subterminal-bipolar, central cells longer than end cells, order of septation 2:1:2.