Flora of New Zealand Series

Byssus candelaris L., Sp. Pl. 2: 1169 (1753).

Thallus crustose-leprose, diffuse (rarely delimited) forming scattered granules in places but chiefly converging to produce a fairly thin ± continuous non-areolate (rarely fortuitously areolate) crust, bright yellow, often with either a slightly orange or a greenish tinge, or rarely greenish-yellow, surface composed entirely of a mass of pulverulent, minutely convex to spherical granules, 0.01-0.1(-0.2) mm diam., cortex absent, thallus unstratified, uniformly yellow throughout, thalline margin absent, prothallus not apparent. Apothecia rare, minute, to 0.5 mm diam., scattered to ± clustered, superficial, orbicular, rarely angular-distorted, disc plane to subconvex, light orange often yellow-pruinose, margins poorly developed to 0.01 mm thick, entire, bright yellow, concolorous with thallus, often occluded in mature fruits, Paraphyses 1-1.5 µm thick, colourless, septate, rather few between asci, these being erect and branched but richly anastomosing above, not swollen apically. Asci clavate, small, 25-33 × 10-13 µm, two walled, the inner extending to form a nipple which may indicate the ascus is of arrested-bitunicate type. Ascospores narrowly obovoid to narrowly ellipsoid, straight or curved, mostly 3-septate (9-)13-14 × 3 µm. Chemistry: Thallus C-, K and KC- or + orange often darkening to red and finally black, Pd-, or + orange. Three chemodemes are present in the species. (i): Calycin, (ii): Pinastric acid. (iii): Calycin and pinastric acid.

N: North Auckland to Wellington. S: Nelson to Southland. St: Very widely distributed, photophobous and nitrophilous, on bark of both native (Dacrycarpus, Dacrydium, Podocarpus) and introduced trees (Acer, Juglans, Quercus, Prunus etc.) and on rocks from s.l. to 1370 m (Laundon loc. cit. p. 116). It is often frequently found on unpainted fenceposts and timbered buildings.

Cosmopolitan

C. candelaris was called Lepraria candelaris and L. flava in earlier accounts of New Zealand lichens. It is a very easily recognised, bright yellow leprose species, more common in ± coastal than inland habitats. In Europe it forms the species-poor association Leprarietum candelaris and in New Zealand too, it is often a dominant epiphyte of introduced trees supporting a poor lichen flora. On podocarps it is often associated with Lecidea ceroplasta and Thelotrema lepadinum. Chemodeme i is found in South I. populations and chemodeme ii in North I. populations.