Flora of New Zealand Series

≡Collema phyllocarpum Pers. in C. Gaudichaud-Beaupré, Voy. Uranie Bot.: 204 (1827).

Description : Thallus orbicular to irregular, 1–3(–6) cm diam., loosely to closely attached. Lobes laciniate to irregularly imbricate and convoluted, rather thin. Margins entire, sinuous, wavy to ragged, dentate–lacerate, phyllidiate. Upper surface lead-grey to bluish or olivaceous, matt or roughened, delicately wrinkled–striate (×10 lens) at margins, more deeply wrinkled centrally, sparsely to densely phyllidiate. Phyllidia, to 1.5 mm tall, flattened, branched–coralloid, often forming a thick, diffract crust centrally. Lower surface naked, concolorous with upper surface or paler, noticeably wrinkled. Apothecia rather sparse, laminal, sessile to subpedicellate, often sunk in phyllidiate crust, rounded, 1–2(–4) mm diam., disc matt, pale to dark red-brown, thalline margin pale-creamish, becoming densely phyllidate, the phyllidia obscuring margins of disc. Ascospores ellipsoidal, submuriform, 20–35 × 12–18 μm.

K: (Raoul I.). On bark of nikau (Rhopalostylis) and mahoe (Melicytus) and from maritime rocks. It is widely distributed in the tropics and subtropics (Sierk 1964: 297; Swinscow & Krog 1988: 140; Verdon1992a; Aptroot 2002e; McCarthy 2003c, 2006; Jørgensen & Nash 2004).

Pantropical

Illustration : Brodo et al. (2001: 407, pl. 460).

Leptogium phyllocarpum is characterised by: the corticolous habit; a wrinkled upper surface having sparse to copiously developed flattened phyllidia both on the upper surface and around the margins of the apothecia when they are present. Conservation of the name Leptogium phyllocarpum Pers., based on a Brazilian neotype, is discussed by Jørgensen (2002f: 568).