Flora of New Zealand Series

U. baileyi (Stirt.) Zahlbr., Denkschr. Akad. Wiss. Wien math.-naturwiss. Kl. 83: 182 (1909).

≡Eumitria baileyi Stirt., Scott. Nat. 6: 100 (1881).

Description : Thallus erect to subpendulous, 5–15(–20) cm long. Holdfast black or occasionally pale to concolorous with thallus. Branches terete to somewhat ridged, 1–1.5 mm diam., pale-grey to dark greenish grey, branching subdichotomous to irregular; apices attenuate, straight or curved. Fibrils sparse to dense on main branches, to 5 mm long. Isidia always present, sparse to dense, solitary or clustered, cylindrical, easily eroded or dislodged, leaving pseudocyphellae. Pseudocyphellae scattered, punctiform or raised. Soralia absent. Medulla dense. Axis hollow, or with a loose web of hyphae, with a pigmented layer (red, pink, ochraceous-yellow, rusty or chocolate-brown) around axis. Apothecia not seen.

Chemistry : Medulla K+ red (often obscured by pigment); containing usnic acid, eumitrin A, ±eumitrin B, norstictic acid (major), ±salazinic acid (minor), connorstictic acid (tr.), galbinic acid (tr.), and hyposalazinic acid (tr.).

N: Northland. In open forest in canopy branches, occasionally also on fenceposts. Known also from Florida, the Caribbean, Central and South America, East Africa, India, China, Taiwan, Japan, Indonesia, Thailand, Malaysia, the Philippines, Papua New Guinea, Australia, and the Pacific (Swinscow & Krog 1974, 1988; Awasthi 1986; Rogers & Stevens 1988; Stevens 1991b [distribution map of the species, fig. 4.6], 1999, 2004b; Brodo et al. 2001; Wolseley et al. 2002; McCarthy 2003c, 2006; Articus 2004).

Pantropical

Illustrations : Swinscow & Krog (1974: 169, figs 1, 2; 1988: 329, fig. 168; 330, fig. 169); Rogers & Stevens (1988: 359, fig. 1); Brodo et al. (2001: 714, pl. 876); Ohmura (2001: fig. 12, D, H); Flora of Australia56A (2004: 99, pl. 27).

Usnea baileyi is characterised by: the corticolous habit; terete branches; fragile, cylindrical isidia that are easily dislodged, leaving pseudocyphellae; a dense medulla with a pigmented layer around the hollow, tubular axis; and a chemistry of eumitrins and depsidones (especially norstictic acid).