Flora of New Zealand Series

≡Degelia rosulata P.M.Jørg. & D.J.Galloway, Fl. Australia 52: 314 (1992).

Holotype: New Zealand. Auckland Is, Crozier Point. i.1963, P.W. James 780D – BM.

Description : Thallus rosette-forming, rosettes of coalescing to ±imbricate squamules, to 3 cm wide. Squamules round to irregular (0.1–) 0.3–1 (–3) mm wide, developed on a prominent black or blue-black prothallus with slightly enlarged marginal lobes. Upper surface becoming lobulate centrally, matt, slatey blue-grey when wet, pale-grey to fawn when dry. Apothecia common, ±central on squamules, 0.1–1.5 mm wide; disc flat, red-brown, with prominent paler proper exciple; thalline exciple variously developed, of secondary lobules arising from base of apothecia, forming a coronate structure; hymenium I+ red-brown. Ascospores simple, ellipsoidal, colourless, 10–15 × 5–8 μm.

Chemistry : TLC−, all reactions negative.

N: Northland (Ngaiotonga, Little Barrier I.), Auckland (Waitakere Ra.), South Auckland Te Morehu Reserve). S: Nelson (Kerr Bay, Lake Rotoiti, Denniston Plateau). St: (Ulva I., Port Pegasus, track from Disappointment Cove to Broad Bay). A: On bark of coastal forest trees and shrubs, Agathis australis, Dracophyllum longifolium, Metrosideros umbellata, Myrsine australis etc. also on Halocarpus bidwillii. Known also from Tasmania from cool, humid rainforest (Jørgensen & Galloway 1992b: 252; Kantvilas & Jarman 1999: 64).

Australasian

Illustrations : Jørgensen & Galloway (1992b: 254, fig. 91A – as Degelia rosulata); Kantvilas & Jarman (1999: 64 – as Degelia rosulata); Jørgensen (2004a: 236, fig. 5).

Degeliella rosulata is characterised by: the corticolous habit; the conspicuous black prothallus extending beyond the edges of the neat, grey-blue to grey, rosette-shaped, tightly attached thallus; and the centrally clustered, reddish to red-brown, conspicuously marginate apothecia with smooth-walled ascospores.