Freshwater Ascomycetes - Species Monograph

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Genus	Species	Author
Annulatascus	velatisporus	K. D. Hyde
Class	Order	Family
Sordariomycetes	Inc. sed.	Annulatascaceae

Synonymy:

Description

Habit:

Ascomata fully or partly immersed or superficial on wood; clustered or scattered.

Ascomata:

Ascomata up to 450 µm high, 260-410 µm diam., globose or subglobose, immersed or semi-immersed, occasionally superficial, carbonaceous, solitary or mostly gregarious, ostiole central or lateral, beaked, black.

Peridium:

Peridium 38-60 µm thick, composed of large brown melanised angular cells with large lumina towards the outside and lighter thin-walled elongate cells towards the center.

Beak:

Beak up to 384 µm long, 140 µm diam., periphysate.

Hamathecium:

Paraphyses wide, septate, tapering, numerous, longer than asci and occurring between asci and extending into the lower neck.

Ascus:

Asci 220-290 x 12-18 µm, 8-spored, cylindrical, thin-walled, peduncle tapering, with a large elongate non amyloid apical apparatus (7-8 µm long x 4-5 µm wide), developing from the base of the ascoma.

Ascospore:

Ascospores 26-42 x 9-12 µm, unicellualar, up to 3 septate in some mature specimens, fusiform, hyaline, uniseriate, verruculose.

Sheath:

Ascospore sheath thin and irregular according to the type description. In collections from North America, the ascospore sheath is rather large. Also in North American collections, the ascus and ascus base extend in length and the ascus base is very sticky.