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Page number:99 
Description type:Original description 
Description:Chaenothecopsis nigripunctata Rikkinen sp. nov. Figs. 1-11
On exudate of conifers (Tsuga heterophylla). Ascomata variable in size, usually 0.8-2.0 mm high. Capitulum lenticular to subhemispheric, (0.25)0.45-0.80(0.90) mm diam. (n = 30), usually polycephalic, formed of 2-8 (12) congregated disks; individual disks (0.25)0.30-0.55(0.58) mm diam. (n = 30). Epithecium with a highly reflective surface, partly thickened by groups of perpendicularly arranged, densely agglutinated hyphae. Excipulum well developed, 10-30 µm thick, confluent between neighboring disks in compound capitula, consisting of periclinally arranged, somewhat swollen hyphae. Hymenium hyaline, clearly delimited from dark stalk hyphae. Mazaedium well developed, dark brown, spores kept together by a thin mucilage. Mature spores extruded between epithecial thickenings, forming multiple mazaedial columns; later the mazaedial elements enlarge and coalesce. Stalks smooth, usually straight, rather stout, (0.07)0.09-0.17(0.20) mm in diam. (n = 30), uppermost part pale, basal section blackish. Outermost layer of stalk formed by pale, irregularly arranged, senescent hyphae, and often covered by a thin pruina of hyphal remains. Inner part of stalk dark, formed by slightly interwoven, largely periclinally arranged hyphae. All parts of the apothecium KOH-. Asci cylindrical, 80-110 x 5-7 µm, with a strongly thickened apex penetrated by a canal. Ascospores uniseriate, obliquely oriented in semi-mature asci and more periclinally oriented in mature asci, 1-septate, brown, ellipsoidal, smooth (11.5)13.0-15.5(17) x (4.5)5-5.5(6) µm (length: x = 14.31, n = 50; width: x = 5.24, n = 50).
Holotype. Rikkinen 98428 (H), isotypes Rikkinen 98428 (UPS), Rikkinen 98428 (US).
Chaenothecopsis nigripunctata has only been found growing on the exudate and wetwood of T. heterophylla in forests of the Pacific Northwest. It thrives in humid microhabitats and commonly occurs in deep shade. It prefers damaged or suppressed trees in old-growth forests.
 
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