Ramalina exiguella
Description : Thallus corticolous, grey-green to yellow-green, erect, rigid, 8–15(–20) mm long, branching mainly basal, but with short lateral branches appearing in some specimens. Holdfast delimited. Branches 2–6 mm wide, subterete to terete, narrow, apices fine. Surface shining or matt, regularly grooved appearing string-like. Pseudocyphellae common, linear. Soralia absent. Apothecia common, few to numerous, marginal and subterminal causing branch tips to become geniculate; disc 0.3–1.7 mm diam., plane to convex, margins entire. Ascospores ellipsoidal, straight or curved, occasionally reniform, 11.5–15.5 × 5–7 μm.
Chemistry : Medulla K−; containing usnic acid.
K: (Raoul I.). N: Northland (Cavalli Is, Bay of Islands, Great Barrier I., Cuvier I.) [map in Bannister et al. (2004: 128, fig. 4)]. On bark of Agathis australis, Avicennia marina, Metrosideros excelsa, M. kermadecensis (Kermadec pohutukawa) and Pinus radiata. Known also from East Africa, Australia, Hawai'i, Tonga and Norfolk I. (Stevens 1987; Swinscow & Krog 1988; Elix et al. 1992b; Elix & McCarthy 1998; McCarthy 2003c, 2006).
Palaeotropical
Illustrations : Stevens (1987: 153, pl. 7, fig. 5; 214, pl. 3, fig. 3); Swinscow & Krog (1988: 281, fig. 139); Blanchon et al. (1996a: 66, fig. 6H; 82, fig. 8H).
Ramalina exiguella is characterised by: the corticolous habit; small thallus size; solid, slender terete to subterete branches; subterminal, geniculate apothecia; and usnic acid as the sole secondary constituent.
