Flora of New Zealand Series

Holotype: Campbell I., tributary Garden Stream, 120 m, damp mossy bank in open gully surrounded by dwarf forest and 'lanes' [with Bryum treuncorum, Lepidozia laevifolia, Lophocolea lenta, L. leucophylla], 5.i.1981, C.D. Meurk – CHR 381041. Isotype – BM.

Description : Thallus 2–5(–8) cm diam., ±loosely attached at base, thin, papery, rather brittle when dry, irregularly spreading or straggling among grasses at base of shrubs, often ±upright. Lobes 2–8(–10) mm wide, 15–30 mm long, ±discrete at margins, contiguous to overlapping centrally, often ±convolute. Margins entire, undulate, wavy to crenulate in parts, or rounded or irregularly lobulate and ragged to ±subimbricate, sinuses prominent, acute to smoothly rounded. Upper surface lettuce-green to olivaceous, tinged brownish at margins when wet, paler when dry, matt or somewhat glossy at apices, or occasionally with small patches of glistening white pruina, smooth, ±papillate in parts (internal cephalodia) without isidia, maculae or soredia. Phyllidia rare to occasional, marginal, 1–2 mm tall, simple to coralloid-branched, 0.2–0.5 mm wide, ±flattened, pubescent and cyphellate below. Photobiont green. Medulla white. Lower surface glossy, pale-whitish or cream, glabrous in a thin, marginal zone, or ±uniformly tomentose from margins to centre; tomentum even, velvety, most conspicuous at margins, often lacking in older parts, white to pale-fawn or occasionally dark-brown in patches; pale-buff to blackened anchoring tufts of rhizines 2–4 mm long may develop on lower surface and at margins. Cyphellae rather widely scattered, minute, not apparent near margins, large and obvious centrally, 0.1–0.8(–1.2) mm diam., round, deeply urceolate, pinprick-like at margins, flatter centrally, margins thin, very slightly raised, usually well-defined above tomentum; pit membrane minutely granular, brilliant-white. Apothecia not seen.

S: Southland (Takahe Valley Fiordland). C: A: Ant: (N of Mt Waterhouse). In open scrub–tussock–bryophyte turf; Coprosma-Myrsine scrub flush; on blanket peat; modified Poa littorosa – Carex appressa – Bulbinella rossii – Pleurophyllum speciosum – Anisotome antipoda tall turf megaherbfield; supralittoral cushion; s.l. to 400m.

Endemic

Illustration : Galloway (1997: 130, fig. 20).

Sticta colinii is characterised by: the terricolous/graminicolous habit; a green photobiont; a white medulla; irregularly laciniate, ±convolute rather straggling lobes with entire to crenulate or irregularly lobulate margins without isidia; a smooth to papillate upper surface, glossy at apices and margins; a pale lower surface with velvety tomentum, sometimes with prominent tufts of brown-black anchoring rhizines (up to 4 mm long) developed at margins and centre; and conspicuous, large, white, widely scattered cyphellae. It is distinct from S. martinii, which has more fragile, lacerate-phyllidiate lobes that are occasionally white-pruinose or pubescent at the margins, and thalli with a distinctive pulvinate or caespitose growth form. The southern South American endemic S. santessonii D.J.Galloway (Galloway 1994c: 268–271) differs in having marginal and laminal isidia and a cyanobacterial photobiont. S. colinii is named for the distinguished ecologist Dr Colin Meurk, who has made extensive collections of plants and lichens from the subantarctic islands of New Zealand.