Chaenothecopsis debilis
≡Calicium debile Turner & Borrer ex J.E. Smith & J. Sowerby, Engl. Bot. 35: tab. 2462 (1813).
Description : Saprophytic on decorticated wood. Algae usually not present. Apothecia intermediate in size, 0.4–1.2 mm tall, black, well-stalked, shining. Capitulum 0.14–0.40 mm diam., lenticular, with or without cottony hyphae on the lower side, when present cottony hyphae making lower side of capitulum appear white-pruinose. Epithecium brown to reddish brown, 5–7 μm thick. Exciple reddish brown. Hypothecium subaeruginose. Exciple and epithecium K−, H+ intensifying aeruginose. Stalk 0.04–0.10 mm diam., black, paler centrally, in section HNO3+ intensifying violet-red, K+ greyish red or K−. Asci 40–54 × 2.7–3.3 μm. Ascospores uniseriate, medium-brown, 6.5–9.5 × 2.2–3.3 μm, smooth or minutely areolate, septum distinct.
N: Northland (Te Paki Bush) to Wellington (Ohakune). S: Nelson (Pelorus Bridge) to Southland (Pourakino Valley). On dry and weathered lignum mainly of Nothofagus fusca, N. menziesii and N. solandri, and also on Agathis australis, Dacrydium cupressinum, Griselinia littoralis, Laurelia novae-zeelandiae, Podocarpus totara and Vitex lucens in forest, s.l. to 900 m. Widely distributed in North America, Scandinavia, Eurasia, Central and South America and Australia (Queensland to Tasmania) (Tibell 1987, 1996b, 1998a, 1999c; McCarthy 2003c, 2006; Nimis & Martellos 2003; Tibell & Thor 2003; Hermansson & Pystina 2004; Titov et al. 2004).
Cosmopolitan
Illustrations : Tibell (1987: 123, fig. 87; 1996b: 42, fig. 27A; 1999c: 86); Goward (1999: 93, fig. 36B).
Exsiccati : Tibell (1986: No. 136).
Chaenothecopsis debilis varies greatly in size. The pruina-like cottony hyphae on the lower side of the exciple are quite distinctive in some collections, but on the whole they are rare. It is characterised by: the 1-septate, medium-sized ascospores with a distinct septum; the reddish brown colour of the epithecium, exciple and outer part of the stalk; and the HNO3+ red reaction of the stalk.
