Flora of New Zealand Series

Holotype: New Zealand. Northland, Kohuronaki, on Metrosideros robusta, sine datum, J.K. Bartlett 25681a – BM. Isotypes: AK, BG.

Description : Thallus orbicular to irregularly spreading, 2–6(–10) cm diam., closely attached, without a marginal projecting prothallus. Lobes narrow, 1–2 mm wide, flabellate–cuneate, rarely discrete to contiguous to imbricate at margins, complex–imbricate centrally, concave at margins to plane or convex. Margins rounded, ±shallowly incised or crenate, often white-tomentose or occasionally ±blackened, noticeably thickened below, becoming densely isidiate towards centre. Upper surface pale to dark grey-blue when wet, marginal areas yellow-grey when dry; minutely granular or leprose–scabrid (×10 lens) at margins, smooth subrugose or ridged, often strongly plicate–wrinkled and densely isidiate centrally. Isidia terete, simple, 0.1 mm diam., or less, granular at first becoming gnarled glomerulate, friable, bluish white or greyish, marginal and on interlobe ridges to occasionally scattered on upper surface or densely crowded–congested and forming a diffract–areolate crust centrally, often ±obscuring entire thallus. Lower surface pale-buff or whitish in a narrow marginal zone, red-brown to black centrally and short-tomentose at margins with tufts of short brownish to black, squarrose rhizohyphae towards centre. Apothecia occasional to rare, often absent, sessile, laminal, rounded to 1.5 mm diam., often obscured by and/or sunk within dense isidiate crust; disc red-brown, matt, proper exciple obscured by persistent, densely isidiate thalline exciple. Ascospores 10–15 × 5–8 μm, with wrinkled perispore.

Chemistry : Pd+ yellow-orange; containing vicanicin, norvicanicin and rarely leprolomin and terpenoids; occasionally Pd− (no compounds).

K: (Raoul I.). N: Northland (Three Kings Is, Radar Bush, Te Paki, Spirits Bay, Mangonui, Waipoua Forest, Ngaiotonga, Hen & Chickens Is, Whangarei Heads, Tapu Bush N. Kaipara, Great Barrier I., Little Barrier I., Cuvier I.), Auckland (Waitakere Ra., Piha, Rangitoto I.), South Auckland (Whitianga Coromandel Peninsula, Motuwai I., Great Mercury I., Red Mercury I., Slipper I., Whale I.). Wellington (Kaitoke). S: Marlborough (d'Urville I.), Westland (Lake Kaniere), Otago (Lake Wilkie Catlins). Mainly coastal and northern on trees (especially Metrosideros excelsa) shrubs and rocks, s.l. to 300 m. Known also from Australia (Jørgensen & Galloway (1992b: 266; McCarthy 2003c, 2006).

Australasian

Exsiccati : Moberg (1994a: No. 134).

Illustration : Jørgensen & Galloway (1992b: 265, fig. 93C).

Pannaria elixii is a variable species. When growing on smooth bark as it frequently does in coastal vegetation of northern New Zealand, it forms ±regular rosettes of radiating, ±imbricate rather thin lobes. When growing on rocks, over mosses or on rough bark it forms more irregular and thicker thalli. Development of isidia is also highly variable, from rather sparse and scattered, to densely covering the whole centre of the thallus.