Flora of New Zealand Series

=Staurothele humistrata Zahlbr., Denkschr. Akad. Wiss. Wien math.-naturwiss. Kl. 104: 251 (1941).

Staurothele humistrata. Lectotype: New Zealand, Gisborne. Te Puia north of Gisborne, on earth covering rock crevices in Leptospermum shrubland, H.H. Allan W 32 –. CHR 378140 [fide Galloway (1985a: 539)].

Description : Thallus terricolous, rarely saxicolous, squamose. Squamae rounded to weakly lobate to rarely deeply lobate, scattered, contiguous or imbricate, plane to convex, rarely concave, pale grey-brown, green-brown, dark reddish brown or brown-black, (0.5–)1–3(–4) mm diam., 0.15–0.25(–0.3) mm thick. Upper surface smooth to slightly wrinkled or hummocky, occasionally sparingly cracked, matt. Margins smooth, rarely crenulate, concolorous with thallus, deflexed to subrevolute. Lower cortex dark-brown. Rhizines 0.05–0.2(–0.3) mm thick, usually richly branched, dark-brown to black with a white hyphal core, anchoring, and often linking squamae. Perithecia simple, immersed, usually solitary, 1–10 per squama, usually visible both apically and as swellings on the lower surface; apex plane to convex, concolorous with thallus to black, 0.15–0.25(–0.3) mm diam.; ostiole inconspicuous to slightly depressed. Centrum globose to obpyriform, 0.2–0.4 mm diam. Exciple brown-black, 20–30 μm thick. Paraphyses evanescent. Periphyses 40–60 μm long, simple. Hymenial algae green, globose–cuboid, 3–4 μm diam., to elongate, 4–6 × 2–3 μm. Asci bitunicate, bisporous, clavate to cylindrical–clavate, 68–100 × 23–28 μm. Ascospores muriform, pale to dark-brown, broadly ellipsoidal to elongate–ellipsoidal to subcylindrical, with 7–11 transverse septa and 3–4 longitudinal septa, (29.5–)44(–58) × (14–)19(–28) μm. Pycnidia usually present, 0.15–0.35 mm diam., immersed, apex plane to convex, dark-brown to black, 0.1–0.2 mm diam. Conidia filiform, 3–5 × 0.5 μm.

N: Gisborne (Te Puia N of Gisborne). S: Otago (widespread on arid, exposed, denuded Central Otago soils, near Alexandra, Cromwell, Tarras etc., Dunedin). On shallow soil over rocks, and on dry, exposed soils between mats of Raoulia australis. Recorded in the earlier literature as Verrucaria pallida as well as Endocarpon pusillum (Nylander 1866b: 259, 1888: 127; Müller Argoviensis 1894: 87). Still very poorly known in New Zealand. Widespread throughout Europe from the Mediterranean to the Arctic, from northern Asia to NW China, Macaronesia, Cape Verde Is, North Africa and Angola, Chad, Zimbabwe, India, the Hawaiian Is, California, Mexico, British Columbia, Bolivia, Brazil, Argentina and Australia (McCarthy 1991c: 40, 2001d: 166, 2003c, 2006; Breuss 1993, 2002c: 186; Goward et al. 1994a; Aptroot 2002e; Becker 2002; Scutari et al. 2002a; Nimis & Martellos 2003; Santesson et al. 2004). In the field it is often confused with Placidium squamulosum (q.v.), but is distinguished by the prominent, black, intertwined rhizines anchoring thallus to soil. Structure and ontogeny of the thallus of E. pusillum was studied by Wagner & Letrouit-Galinou (1988).

Cosmopolitan

Illustrations : Zschacke (1934: 653, fig. 342); Yoshimura (1974: pl. 45, fig. 485); McCarthy (1991c: 39, fig. 5); Harada (1993b: 337, fig. 1b; 347, fig. 6); Goward et al. (1994b: 35, fig. 1A; 52, fig. 1A); Hansen (1995: 89); Wirth (1995a: 24, fig. 9); Brodo et al. (2001: 308, pl. 321); Scutari et al. (2002a: 376, fig. 5C, D); Sérusiaux et al. (2004: 79).

Endocarpon pusillum is characterised by: the terricolous/saxicolous habit; squamae rarely exceeding 3.5 mm diam.; the bisporous asci, the dark underside and the thick, blackened rhizines (McCarthy 1991c).