Nectria dentifera Samuels 1976
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Nomenclature
Classification
Descriptions
Nectria dentifera Samuels 1976
CONIDIAL STATE: Acremonium sp.
Mycelium not visible. Perithecia solitary. yellow to orange, globose, 200-250 µm diam., with an apical, stellate crown of hairs, becoming collabent or not collapsing when dry, not changing colour in 3% potassium hydroxide. Perithecial wall 20-25 µm thick. Surface view: cells prosenchymatous, walls 1-2 µm thick. Longitudinal section: outer region 10-15 µm wide, cells prosenchymatous, walls of cells 1-2 µm thick; inner region 5-10 µm wide, cells ellipsoidal to flattened, 5-15 µm long x 2-3 µm wide, walls c. 1 µm thick and pigmented, cells becoming progressively more flattened toward the interior. Perithecial hairs fasciculate, forming a yellow, stellate, apical disc, 150-200 µm diam.; composed of unbranched, septate, tightly bound hyphae, 3-4 µm wide with walls 1-2 µm thick; arising from the prosenchymatous region of the outer perithecial wall. Perithecial papilla lacking or short and acute, ostiolar opening formed by narrow, hyphal elements arising from the inner region of the Perithecial wall; ostiolar canal periphysate. Asci cylindrical, 45-55 x 5-6 µm, 8-spored; apices rounded, with a ring; bases rounded; ascospores uniseriate, forming throughout the length. Ascospores elliptical to fusiform-elliptical, 6-8 (-9) x 3-4 µm, equally 2-celled with one drop in each cell, finely spinulose., not constricted at the septum, hyaline.
CHARACTERISTICS IN CULTURE CMD: Ascospores germinating overnight, one short germ tube arising from each cell. Colonies 2-3.5 cm diam., translucent to opaque, white to pale pink, aerial mycelium loose and cottony, margin undulate, non-aromatic, medium non-pigmented. ME: 1-1.5 cm diam., opaque, white to pale pink; aerial mycelium as erect, outwardly directed, hyphal, rope-like strands; margin undulate, non-aromatic, medium non-pigmented. OA: 2-2.5 cm diam., opaque, white; aerial mycelium as hyphal, rope-like strands; margin undulate, non-aromatic, medium non-pigmented. WAS: 4 cm diam., transparent, white, aerial mycelium sparse, margin undulate, non-aromatic, medium non-pigmented. Phialophores forming on CMD, ME, OA, and WAS, arising from the surface of the agar and from the aerial mycelium; monophialidic, or irregularly and frequently branched, 0-2 septate, straight, smooth. 22-58 µm long, 2-3 µm wide basally, subtending hypha 2-3 µm wide. A solitary phialide constituting the terminal (9-) 20-40 (-50) µm of each phialophore, 1-1.5 µm wide at the unflared tip. Phialoconidia globose, 2-3 µm diam., to broadly elliptical, 3-4 x 2.5-3 µm, unicellular, hyaline, with a slightly protuberant, flattened, basal abscission scar. Arising in basipetal succession and held in a solitary drop of hyaline liquid.