O. batistae has been collected mixed with as many as four other sooty moulds and rarely as a more or less pure growth. These resultant spongy subicula (Fig. 5) are flattened and restricted, about 4 mm thick, or extensive and very variable in size and configuration, with a very irregular lumpy surface with the rounded lumps up to 20 mm thick. In such a mixture of moulds a concentration of O. batistae can be identified by its rusty-brown colour, although this may darken with age. O. batistae was found to be a common component of the sooty mould flora which often enveloped trunks of Nothofagus fusca and N. solandri var. cliffortioides in Westland and Canterbury.

The mycelium (Fig. 5, 6) is brown to very dark brown, composed of copiously branched, septate, strongly constricted moniliform hyphae which taper characteristically toward their distal ends; only occasional anastomoses have been seen. Hyphae are straight or curved, for the most part smooth or sparsely roughened; the distal ends of hyphae are very coarsely roughened. The older basal cells are darkest, up to 45 µm wide, up to 30 µm long, very thick-walled, and the outer layer of the cell wall may crack, to give a reticulate appearance; the end cells of hyphae may be as narrow as 7.5 µm. The vast majority of cells are broader than they are long in the ratio of 1.3-1.5 to 1. The mycelium possesses the remarkable capacity of being able to break up, by a natural separation at the septa, into fragments (Fig. 5) which at first may bear lateral branches and which by further separation may fall apart into unbranched portions of hyphae of varying length. These may be 20 to 30 cells long, but usually they are shorter and composed of fewer cells; one-celled fragments are not uncommon and these are subglobose. The detached ends bulge out to become rounded and each scar is a smooth circular area limited by a ridge, with a small central septal pore (Fig. 5, 6). The scars left by the detachment of lateral branches are similar to these. In mixed subicula of various sooty moulds the mycelium of O. batistae can usually be identified not only by its colour but more readily by the irregular heaps of separated hyphae. When portions of such aggregations are placed in water there is often complete disintegration into fragments. These hyphal fragments very probably function as propagative units.

Capnophialophora phialides (Fig. 6, 7) have been observed on entire and on fragmented mycelial hyphae, and on ascospores. They develop singly, in pairs, or in groups of three directly from cells of hyphae or on one- to many-celled, narrower, simple or compound lateral branches; when numerous and crowded they appear in botryose clusters. They are also produced singly, less frequently in pairs, from cells of ascospores or on short, one-celled branches arising from these; occasionally an ascospore cell becomes modified into a phialide and develops a collarette. Phialides are more or less barrel-shaped, pale brown to brown, rough-walled, and bear a single, rarely two, terminal collarettes. Collarettes are more or less cylindrical or wider at the base than at the apex, which is rounded and closed at first, finally with an irregular open end. Phialide cells are 7.0-7.5 µm long, 7 µm wide and the collarettes 3.5-5.0 µm long and 3.5 µm wide. Very few phialospores have been seen; they are broadly ellipsoidal, hyaline and about 1.5 µm long. Phialides occasionally proliferate to produce a second phialide. Proliferation starts deep within the collarette to form a relatively thick-walled, obovoid cell, 4.0-5.0 µm long and 3.2-3.6 µm wide; at this stage the cell is included within the confines of the collarette, but this is torn as the cell expands and develops into a phialide similar to the one that bears it.

Perithecia are basally immersed, dark brown to black, scattered or in groups, subglobose, 220-400 µm in diameter and ostiolate at maturity. From an early stage they bear simple moniliform hyphal appendages (Fig. 6) up to 140 µm long and up to 8-septate; these are tapering, smooth or slightly roughened, occasionally anastomosing, and merge with the subiculoid hyphae attached to the lower part of the perithecium. The perithecial wall is 30-40 µm thick, being cemposed of an inner layer of compressed cells which merge gradually with the outer layer of more deeply coloured pseudoparenchymatous cells. Asci are fasciculate, ellipsoidal to obclavate, b tunicate, 120-200 x 30-63 µm, with 2 to 8 mature ascospores. At maturity, ascospores (Fig. 7) are in a parallel fascicle or overlapping series within the ascus; they are subcylindncal with tapering ends to broadly ellipsoidal, straight or curved, generally widest just above the middle, brown to very dark brown, rounded at the ends, thick-walled, and not or slightly constricted at the septa. They are very variable in size and septation, being transversely 6-20-septate and 47-167 X 16-24 µm with one, seldom two, longitudinal septa in as few as one or two cells or in all the cells except the terminal ones. The longer and narrower ascospores generally have fewer longitudinal septa than the shorter and broader ones, and when such septa are few in number they are usually found in the broader part of the ascospore. Ascospore initials are ellipsoidal with hyaline walls and are irregularly crowded or loosely arranged; there are usually eight in each ascus but sometimes less, and one or more may fail to develop further. The initials elongate to become narrowly ellipsoidal and septa are laid down in an intercalary manner and not in centrifugal succession as in Ophiocapnocoma phloiophilia. Septation is accompanied by pigmentation, the developing ascospores becoming yellowish, then somewhat olivaceous, and at maturity a dark brown.

Subiculum irregulare, planum vel rotundatum, spongiosum, plerumque aliis speciebus mixtum, ferrugineo-brunneum vel strum.

Mycelium superficiale, ex hyphis ramosis, subulatis, septatis, moniliformibus, brunneis vel atro-brunneis, levibus vel asperis, interdum anastomosantibus, com¬positum. Hyphae ad 45 µm lat., ad 7.5 , µm subulatae, in fragments (1-30-cellulata) secendentes. Phialides (Capnophialophora) singulares vel botryosae, subsphaericae, pallide¬brunneae vel atro-brunneae, 7.0-7.5 µm long., 7 µm lat., paulum asperae, strophio singulo (raro duobus) terminali subcylindrico pallidiore 3.5-5.0 µm long., 3.5 µm lat., praeditae. Phialides frequenter in ascospons germinantibus productae. Phialospora late ellipsoidea, hyalina, ca. 1.5 µm longa.

Perithecia ad basim immersa, brunnea vel atra, subglobosa, 220-400 µm diam., ad maturitatem ostiolata, hyphis simplicibus, moniliformibus, subulatis, ornata. Asci fasciculati ellipsoidei vel obclavati, bitunicati, 2-8-spori, 120-200 x 30-63 µm. Ascosporae fasciculatae vel irregulariter multiseriatae, subcylindricae vel late ellipsoideae, rectae vel curvatae brunneae vel atro-brunneae, utrinque rotundatae, ad septas non vel paulo constrictas, pervariabiles, transverse 6-20-septatae, 47-167 x 16-24 µm; cellula unica vel cellulae omnes (terminalibus exceptis) septis longi¬tudinalibus singulis praeditae. Habitat: in truncis ramulisque arborum vivorum, verisimiliter cum liquore mellifluo (aliter dictum "Honey-dew") ab insectibus excreto consociatus. Typus: in truncis Nothofagi solandri var. cliffortioidis, New Zealand, Canterbury Province, Broken River, near Enys, Craigieburn Range, 16.V.1963, J. M. Dingley, PDD 25074 (DAOM 105925a).