Flora of New Zealand Series

=Leptogium cyanescens, sensu Nyl., Syn. meth. lich. 1 (1): 131 (1858) non (Rabenh.) Körb.

Description : Thallus orbicular to irregularly spreading, 1–2.5(–4) cm diam., closely attached to bark substratum or loosely attached to mosses. Lobes variable, broadly rounded, ±flat, 5–10(–15) mm diam, to folded, crowded–congested and ±imbricate, rather thin and papery, pliable when wet, brittle when dry. Margins entire, sinuous to ragged–incised, often ascending, isidiate. Upper surface dark lead-grey or bluish black when wet (±translucent at margins), dull lead-grey when dry, undulate or shallowly crumpled, minutely wrinkled–striate (×10 lens), the wrinkles ±longitudinally aligned from margins to centre, but often unorientated, the surface appearing velvety to ±scurfy, isidiate. Isidia marginal and laminal in often ±diffract patches, granular at first then terete, styliform, the apices slightly swollen, at length becoming ±coralloid, to 0.2 mm tall, concolorous with thallus or slightly darker. Lower surface concolorous with upper surface at margins, paler to ±creamish or brownish centrally, naked, or rarely with scattered granular isidia developing on upturned margins of lower surface, distinctively minutely wrinkled–papillate, ridges of wrinkles pale, forming an irregular, marbled pattern (x10 lens), attached to substratum by scattered tufts of minute, white hairs. Apothecia not seen.

N: Northland (Three Kings Is). An epiphyte of Kunzea ericoides and Litsaea calicaris, and on mosses on the floor of open Kunzea forest. It associates with other species of Leptogium (L. austroamericanum, L. cyanescens, L. denticulatum) and species of Pseudocyphellaria (P. aurata, P.chloroleuca, P. crocata, P. pickeringii, P. poculifera and P. wilkinsii) in these habitats. It is distinguished from L. cyanescens by the smaller, granular isidia and the delicately wrinkled, scurfy surface of the lobes. L. austroamericanum is very similar but has larger, more flattened phyllidia and an often more densely wrinkled surface. Known also from Sri Lanka (Nylander 1900), Nuku Hiva, Marquesas Archipelago (Nylander 1858) Tongatapu (Crombie 1877) and New Caledonia (Nylander 1867b).

Palaeotropical

Leptogium cyanizum is characterised by: the corticolous habit; broad lobes that are minutely longitudinally wrinkled–ridged, and scattered here and there with minute, granular to terete or subcoralloid isidia, giving the surface of the lobes a rather scurfy texture as noted for the species by Nylander (1900: 4).