Hypotrachyna imbricatula
≡Parmelia imbricatula Zahlbr., Denkschr. Akad. Wiss. Wien Math.-naturwiss. Kl. 83: 168 (1909).
Description : Thallus adnate, to 5–10 cm diam. Lobes often crowded, sublinear, subdichotomously branched, 2–4 mm wide, margins entire, apices incised. Upper surface whitish grey often turning pale buff or tan in herbarium, flat, shining, usually strongly white-maculate, without soredia and pustules, isidiate. Isidia moderately dense to dense, cylindrical, simple to branched, slender, occasionally lobular–procumbent and darkening at apices. Medulla white. Lower surface densely rhizinate, black, rhizines richly dichotomously branched. Apothecia not seen.
Chemistry : Cortex K+ yellow, UV−; medulla K−, C−, KC+ yellow-orange, Pd−; containing atranorin, chloroatranorin, barbatic acid (major), obtusatic acid (submajor/minor), 4- O- demethyl barbatic acid (minor) and norobtusatic acid (tr.).
N: South Auckland (Ohope Beach). S: Nelson (N of Waimangaroa). On pohutukawa (Metrosideros excelsa) and on Dacrycarpus dacrydioides in lowland, coastal forest (Elix & Johnston 1991). Known also from Mexico, Central and South America,, Hawai'i, SE Asia, Papua New Guinea and Australia (Aptroot 2002e; Louwhoff & Elix 2002a: 58–59; Nash et al. 2002b; Wolseley et al. 2002; McCarthy 2003c, 2006).
Pantropical
Illustrations : Hale (1975: 43, fig. 12a); Louwhoff & Elix (2002a: 61, fig. 21).
Hypotrachyna imbricatula is characterised by: the corticolous habit; the cylindrical isidia, densely dichotomously branching rhizines and barbatic acid in the medulla
