Flora of New Zealand Series

S. leptaleum Nyl., Syn. Meth. Lich. 2: 251 (1860).

S. detergens Nyl., Lich. N.Z.: 16 (1888).

S. humile Müll. Arg., Bull. Herb. Boissier 4: 88 (1896).

S. wadei Lamb, J. Hattori bot. Lab. 43: 305 (1977).

Holotype: New Zealand. Wellington "... on rocks Mt Tarahi and Cape Palliser". W. Colenso 5144, H-NYL 40026.

Thallus rather small, to 2-3 cm tall, robust specimens to 6 cm tall, spreading, without a defined holdfast and often forming dense compact colonies amongst mosses or on small boulders and stones in damp places. Pseudopodetia smooth, rarely slightly furrowed, mostly ± terete or slightly flattened, becoming branched in upper parts, ± extensively corticate, cortex continuous or in flaky patches. Phyllocladia sparse and often poorly developed, ± indistinguishable from finer corticate pseudopodetial branches, or granular-papillate, spherical, rather variable in shape, sorediate. Soredia granular, white, present on most parts of the thallus, in part derived from the breakdown of phyllocladia. Cephalodia attached to main stems, sessile or shortly stalked, pale brownish- grey, rounded-globose at first, becoming scrobiculate-impressed, cortex smooth or slightly maculate. Apothecia rare, terminal, occasionally also lateral, to 1.5 mm diam., disc convex, brown or blackish-brown, immarginate. Hypothecium colourless. Ascospores acicular-fusiform, 3-septate, 35-50 × 2-3 µm. Chemistry: Atranorin, rangiformic and norrangiformic acids. Some specimens contain also perlatolic, glomelliferic and glomellic acids in place of rangiformic and norrangiformic acids.

N: Three Kings Is, to Wellington. S: NW Nelson to Fiordland. St: Mt Anglem to Port Pegasus. Widely distributed although not a common species, from s.l. to 2100 m.

Austral

S. corticatulum is characterised by the presence of soredia and is the only species of Stereocaulon in New Zealand to have these structures consistently present, although the degree of production of soredia is variable, ranging from a few erose phyllocladia, to a dense, granular covering of the whole thallus. S. corticatulum is very variable, depending on microhabitat and microclimate, ranging from small, appressed almost crustose forms in dry, exposed situations, to ± robust forms in damp, shaded situations. Boekhout [ J. Hattori bot. Lab. 53: 483-511 (1982)] records that part of the FH holotype of S. wadei is referable to S. delisei Bory. This last species is also moderately common on lava on Rangitoto I.