Pyrenothrix nigra
Description : Flora (1985: 487).
N: Northland (Tokatoka, Waiwera near Warkworth), Auckland (Anawhata). S: Nelson (Puponga). On bark of Cordyline australis and on flaking bark of Leptospermum scoparium, and also growing on thalli of the lichens Arthonia, Porina, Pyrenula, in humid, shaded habitats. Commonly forming an association with Dictyonema sericeum and Polychidium contortum, and also with Chrysothrix candelaris, Lecanactis subfarinosa and species of Pertusaria. Known localities are highly oceanic. At Tokatoka, the grove of Cordyline australis where P. nigra occurs is richly covered with species of Pannariaceae (Coccocarpia pellita, Erioderma sorediatum, Pannaria elixii, P. fulvescens) and spectacular rosettes of Pseudocyphellaria aurata. Known also from Florida (Tschermak-Woess et al. 1983; Herrera-Campos et al. 2005).
?Pantropical
Illustrations : Henssen (1964: 319, figs 1–3; tab. VI, figs 8–12 – as Lichenothrix riddlei); Tschermak-Woess (1983b: 295, fig. 1F; 297, fig. 2F; 299, fig. 3C; 301, fig. 4A, B; 302, fig. 5; 303, fig. 6G; 305, fig. 7E – as Lichenothrix riddlei); Herrera-Campos et al. (2005: 359, fig. 3C, E–F).
Pyrenothrix nigra is characterised by: the corticolous habit; the brownish black filamentous thallus consisting of filaments of Scytonema surrounded by a tight envelope of the mycobiont; the minute, pyriform, ostiolate perithecia; and muriform, brown or brown-black ascospores. Because of its small size it is often overlooked. It is undoubtedly more widespread in shaded, northern coastal habitats.
