CONIDIAL STATE: Acremonium sp.

Mycelium white, flat, spreading over the substrate. Perithecia densely gregarious in groups of up to 100, each aggregate enclosed in white hyphae; orange, globose, 220-375 µm diam., to broadly obpyriform, 200-300 µm high x 220-280 µm wide, becoming collabent when dry, not changing colour in 3% potassium hydroxide. Perithecial wall 30-50 µm thick. Surface view cells obscured by the hyphal covering. Longitudinal section: outer region 10-30 µm wide, cells prosenchymatous to hyphal, walls c. 1 µm thick, cells becoming progressively more compacted toward the interior of the perithecial wall. Inner region 15-20 µm wide, cells elliptical to flattened, 5-15 µm long, x 2-3 µm wide, walls c. 1 µm thick, cells becoming progressively more flattened and compacted toward the interior. Hyphal covering white, composed of branched, septate, smooth, straight to slightly wavy, flexuous, 2-3-um-wide hyphae with walls 1-2 µm thick; many free ends visible; hyphae around the ostiolar opening short. Hyphae of the covering arising from the surface of the perithecial wall; covering enclosing 2 or more adjacent perithecia. Perithecial papilla short, acute, composed of narrow hyphal elements arising from the inner region of the perithecial wall; ostiolar canal periphysate. Asci broadly cylindrical to clavate, (41-) 55-70 (-80) x (5.5-) 7-8 (-9) µm, 8-spored; apices rounded, with an indistinct ring; bases rounded to pointed; ascospores biseriate, forming throughout the length. Ascospores fusiform, allantoid or ellipsoidal, 9-12 (-14) x 3-5 µm, equally 2-celled, one drop in each cell, striate or punctate-striate, non-constricted or slightly constricted at the septum, hyaline.

CHARACTERISTICS IN CULTURE CMD: Ascospores germinating overnight, a short germ tube arising from each end of each ascospore. Colonies 1.7-3 cm diam., translucent to opaque, white to pale pink, aerial mycelium loose, margin entire to undulate, non-aromatic; medium non-pigmented or rarely a pink pigment spreading through the medium. ME: 1 cm or less diam., opaque white to pale pink or salmon, aerial hyphae lacking to sparse and loose, margin undulate, non-aromatic, medium non-pigmented. OA: 2 cm diam., opaque, white at the margin, tan elsewhere, aerial mycelium consisting of a few white, hyphal, rope-like strands arising from the original inoculum, margin undulate, non-aromatic, medium non-pigmented. WAS: 1.5 cm diam., translucent, white, aerial mycelium scanty, margin undulate, non-aromatic, medium non-pigmented. Phialophores forming on CMD, ME, and WAS from the surface of the agar and from the aerial mycelium, unbranched, monophialidic, 0-1 septate, straight or sinuate at the tip, smooth, 30-70 µm long, 2-3 µm wide basally, subtending hypha 2-3 µm wide. A solitary phialide constituting the terminal (30-) 40-60 µm of each phialophore, 1-1.5 µm wide at the unflared tip. Conidial production abundant. Phialoconidia ellipsoidal to nearly cylindrical. 6-7 (-9) x 2-2.5 µm, many elongating to 10-19 µm, unicellular, hyaline, lacking a basal abscission scar. Arising in basipetal succession, held in a single, terminal, hyaline drop of liquid.