Monographs Details: Ascolectus albus Samuels & Rogerson
Authority: Samuels, Gary J. & Rogerson, Clark T. 1990. New ascomycetes from the Guayana Highland. Mem. New York Bot. Gard. 64: 165-183.
Description:Species Description - Ascomata 425-475 Atm diam., in subiculo albo insidentia, sessilia, superficialia, solitaria vel cespitosa, hymenio pallide luteo, 100 µm alta sicco. Paraphyses 1 µm lata, apicem ramossissime, rami brevi, uncati, reticulati. Asci lati cyUndrici, 60-75 X (7-) 8-12 µm, bitunicati, 8-spori. Ascosporae filiformes, 37-50 X (2-)3-4 µm, 7-15-septatae. Ascomata seated in a white subiculum, sessile, broadly attached, superficial, solitary or cespitose in groups of a few in aggregates of ca. 1 m m diam., apothecioid, discoidal, 425-475 µm diam. when dry, 100 µm high when rehydrated; hymenium covered with white hyphae when young, exposed at maturity, pale yellow. Medullary excipulum ca. 25 µm wide, of intertwined, ca. 1 Aim wide hyphae, not differentiated from the ectal excipulum, extending laterally into the ectal excipulum. Ectal excipulum uniformly ca. 25 µm wide, not extending above asci, of intertwined, ca. 1 µm wide hyphae, at interior merging with the paraphyses, at exterior hyphae 2-2.5 µm wide,

Distribution and Ecology - BrazU (Amazonas), known only from the type.


Hab.: In foliis Phenakospermum guianense.

Holotypus: Brazil (Samuels 964, N Y ).

Anamorph: None known

Habitat. O n dark mycelium on dead leaf of Phenakospermum guianense.

Etymology of the Specific Epithet. Albus refers to the white color of the apothecia.

TYPE. BRAZIL. Amazonas: Serra Araca, track leading SE from camp, vie. Rio Jauarl, igap6, ca. 00º49'N, 63º'W, elev. ca. 60 m, on Phenakospermum guianense, 15, 16 Mar 1984, Samuels (964) & Bowles (holotype INPA, isotype NY).

Notes. Apothecia of Ascolectus albus are apparently saprobic on dead leaves of Phenakosperm u m guianense, but m a y be parasitic on the dark hyphae that are conspicuously intermingled with hyphae of A. albus below the apothecia.

Ascolectus fits the anatomical concept of the family Saccardiaceae (Arx & Miiller, 1975), which is characterized by superficial, in part apothecial, herbicolous ascomata that have bitunicate asci interspersed with apically branched paraphyses. Ascomata of the genera included by Arx and Miiller (1975) in the family have brown pigmentation, colorless to brown ascospores, and brown hyphae. There is no dark pigmentation in hyphae or ascomata of Ascolectus albus. Rossman (1987) discussed two genera of apothecial loculoascomycetes, Hyalosphaera F. L. Stevens and Nematothecium H. & P. Sydow. Although these genera are characterized in part of lightcolored apothecia and phragmosporous or scolecosporous ascospores, paraphyses are scant to lacking, and apothecial anatomy differs from that in A. albus. Arx and Muller (1975) included Nematothecium in the Dimeriaceae MiiUer & Arx in Arx & Muller