On unknown, host, Auckland, Waitakere Dam, 9.II.l966, R .F. R. McNabb, 24999.

Fructifications waxy-gelatinous, resupinate, thin, effused, indeterminate, forming areas many cm in extent, pruinose, pallid brownish-cream when fresh, drying to an almost invisible, vernicose film; margins concolorous, adnate. In section 200-300 µm thick, consisting of basal layer and hymenium, occasionally two or more growth layers present. Basal layer to 15 µm thick, composed of indistinct, agglutinated, hyaline hyphae lying parallel with substratum, clamp connections present. Hymenium composed of dikaryophyses, gloeocystidia and basidia; dikaryophyses abundant, nodulose, finely and irregularly branched apically, projecting beyond basidia; gloeocystidia cylindrical to subclavate, arising from basal hyphae or base of fertile hyphae, often extending through several growth layers, hyaline at first, contents becoming yellow, granular, 59-112-(220) x 4.2-6.8 µm; probasidia clavate, long-stalked, proliferating through basal clamp connections, 26-38 x 8.4-11.3 µm becoming longitudinally cruciate-septate, longitudinal septa diverging basally to delimit inflated apical portion from stalk, stalk about one half total length of basidium; sterigmata cylindrical, to 38 x 3.5 µm. Basidiospores broadly cylindrical, slightly curved-cylindrical, or ovate and flattened on one side, hyaline, apiculate, 9.7-13 x 4.9-6.5-(7.2) µm. Germination by repetition.

Dead angiosperm wood.

Rogers, Pacif. Sci. 1: 98, fig. 2. 1947; Wells, Lloydia 20: 55, fig. 7. 1957.

The distinctive gloeocystidia indicate that this species belongs in sect. Bourdotia. Although not specifically mentioned, Sebacina petiolata appears to be one of the species that Luck-Alien (1963) would transfer to Exidiopsis subg. Bourdotia. Both Rogers (1947) and Wells (1957) remarked on the similarities between Sebacina petiolata and S. galzinii, the type species of Bourdotia. Luck-Alien considered that waxy-gelatinous species included in Bourdotia by Wells (1961) were related to species such as Exidiopsis laccata (Bourd. & Galz.) Luck-Alien, through their mode of basidium formation and presence of branching dikaryophyses forming a layer above the basidia.
The distinctive characters of Sebacina petiolata are the waxy-gelatinous fructifications, clavate basidia with elongate stalks, finely and irregularly branched dikaryophyses, and long slender gloeocystidia. It is a species of mainly tropical distribution and has not previously been recorded from New Zealand.

Likiep Atoll, Marshall Islands.