Gymnoderma melacarpum (F.Wilson) Yoshim.
Phyllis melacarpa F. Wilson., Vict. Nat. 6 (4): 68 (1889).
Primary thallus squamulose-laciniate, small, convex, sublinear, irregularly lobed-multifid, margins irregularly crenulate. Podetia short 1-3 mm tall, simple or coralloid, terete to laterally compressed, solid, often crowded forming a ± diffract spreading crust. Surface smooth, often shining, occasionally cracked, greenish-brown above, cream or yellowish-brown below. Medulla white. Apothecia sessile on the tips of fertile podetia, often sunk below the surface of clustered sterile podetia, convex, peltate black or brownish-black, shining 0.5-1 mm diam. Ascospores simple, colourless, ovoid-ellipsoid, 5-12 × 4-7 µm. Chemistry: Thallus and medulla K-, C-, KC-, Pd+ red or -. Melacarpic, congrayanic, grayanic and fumarprotocetraric acids [Chester and Elix Aust. J. Chem. 33: 1153-1156 (1980)].
N: Three Kings Is to Wellington. S: Nelson to Fiordland. St: Mt Anglem to Port Pegasus. Widely distributed in forested areas, on tree trunks, on decaying logs and on bare soil on the forest floor, coastal and inland, s.l. to 1200 m.
Australasian
In the past in several New Zealand collections specimens of G. melacarpum were misidentified as Sphaerophoropsis stereocauloides, a South American plant not occuring in New Zealand. In a letter to Charles Knight (preserved in WELT) written by the Rev. F. R. M. Wilson from his home at Kew, New South Wales, on 20 August 1888, Wilson observed " ... I suppose that you have not examined the specimens sent in May. But I cannot refrain from sending you some more. Perhaps the two most interesting of these are the Amphiloma and the plant which I propose to call "Phyllis melacarpa". I cannot find a place for it either in the genus Cladonia or in the subgenera Pycnothelia or Cladina or in Baeomycei. The spores are 8 in the ascus, colourless, simple, ovato-ellipsoid, 0.006-0.008 mm long and 0.004-0.005 mm broad, containing often one to three globules. Paraphyses indistinct, fuscescent, apices fuscous. Gelatinous hymenium blue with iodine. The thallue is composed of laxly interwoven filaments both simple and ramose, 0.002-0.005 mm thick; with gonidia light green, spherical or oblong, 0.005-0.007 mm diam., gathered into clusters close to the upper surface of the thallus..."
G. melacarpum is an epiphyte of the following trees Griselinia, Nothofagus, Metrosideros, and in subalpine habitats, particularly in southern New Zealand it forms clumps among mosses on peaty soil in exposed grassland heaths.
