New Zealand: NORTHLAND: Puketi S.F., Picnic Area, Bush Walk, on Knightia excelsa, P. R. Johnston, G. J. Samuels, 16.IV. 1982 (PDD 44664); Mangamuka Summit, on undetermined leaf, P. R. Johnston, G. J. Samuels, 15.IV.1982 (PDD 44665). AUCKLAND: Waitakere Ra., Centennial Track, on Astelia solandri, P. R. Johnston, 12.X. 1982 (PDD 43317); Waitakere Ra., Cowan Track, on Knightia excelsa, P. R. Johnston, G. J. Samuels, R. H. Petersen, 27.IV.1983 (PDD 44670); Clevedon, Morehau Reserve, on Knightia excelsa, P. R. Johnston, G. J. Samuels, R. H. Petersen, 5.V.1983 (PDD 44672); ibid., on Metrosideros fulgens, P. R. Johnston, E. M. Gibellini, 22.V. 1984 (PDD 45196); Waitakere Ra., Sharp's Bush, on Knightia excelsa, P. R. Johnston, 28.XI.1983 (PDD 44673). COROMANDEL: Papa Aroha, Rautawhake Stream, on Metrosideros fulgens, P. R. Johnston, E. M. Gibellini, 12.VIII.1984 (PDD 45362). TARANAKI: Mt. Egmont, Puniho Track, on Knightia excelsa, P. R. Johnston, G. J. Samuels, R. H. Petersen, 25.IV.1983 (PDD 44669); Mt. Egmont, Waiweranui Track, on Weinmannia racemosa, P. R. Johnston, G. J. Samuels, R. H. Petersen, 25.IV.1983 (PDD 44671). NELSON: Karamea, Umere Rd., on Pseudopanax sp., P. R. Johnston, G. J. Samuels, R. E. Beever, R. H. Petersen, 14.IV. 1983 (PDD 44668). WESTLAND: Fox Glacier, Lake Gault, on Pseudopanax sp., P. R. Johnston, 10.IV.1983 (PDD 44667); Fox Glacier, Mt. Fox Track, on Pseudopanax colensoi (Hook. f.) Philipson, P. R. Johnston, G. J. Samuels, R. E. Beever, R. H. Petersen, 8.IV.1983 (PDD 44666).

South America: COLOMBIA: Dpto. Valle del Cauca, Buga-Buenaventura Rd, on unidentified leaves, Dumont, Molina, 30.VIII.1976 (NYC07552). VENEZUELA: Edo. Aragua, Parq. Nac. Henry Pettier, Maracay, on unidentified leaves, Dumont, Haines, Samuels, 13.VI.1971 (NY-VE2112). Central America: CUBA: Cuba Fungi 442, C. Wright (Phacidium limitatum - K - holotype).

Ascocarp intraepidermal. In vertical section upper stromatal layer 20-40 µm wide, not extending as far as the lower wall. Small cap of dense, black tissue around opening, otherwise of brown to dark brown, pseudoparenchymatous cells, 4-7 µm diam. Lower stromatal layer 8-15 µm wide, of 1-2 layers of thick walled, brown to dark brown, more or less globose cells, 5-10 µm diam. Subhymenium 10-20 µm wide, of thin walled, hyaline, globose cells, 7- 10 µm diam., a layer, up to 50 µm wide, of loose hyphae and crystals present between subhymenium and lower wall. Excipulum becoming well developed, up to 50 µm wide, arising from inner layers of upper wall, comprising several rows of hyaline, closely septate hyphae, becoming slightly swollen and covered by a dark brown substance at apices. Excipulum formed after the ascocarps have opened, and may not be apparent in young, recently opened ascocarps. In young ascocarps has the appearance of a well developed layer of short, hyaline, cylindric periphyses. These become longer and develop septa to form the excipulum.

Paraphyses 2-3 µm diam., gradually increasing in width to 3.5-4.5 µm diam. at apices, extending 15-20 µm beyond asci. Asci cylindric, tapering slightly to a rounded apex, 95-125 x 4-5(-5.2) µm, either uniformly thin walled, or sometimes with an apical thickening, with a short, broad pore, non-amyloid, 8-spored. Ascospores filiform, 44-75 x 0.8-1.0 µm, straight or irregularly curving when released, not tapering, 0-1 septate, gelatinous sheath poorly developed.

Pycnidia intraepidermal, lenticular. Lower wall 8- 10 µm wide, of 2-3 layers of thick walled, dark brown, flattened cells, 2-4 µm diam. Upper wall almost obsolete, consisting of a few hyaline, thin walled cells beneath the cuticle, and a small group of dark walled cells around the ostiole. Conidiogenous layer not seen (see notes below).

HABITAT: Found on fallen leaves of Knightia excelsa, Pseudopanax species, Astelia solandri A. Cunn., Clematis paniculata Gmel., Elaeocarpus dentatus J. R. et G. Forst.) Vahl., Metrosideros fulgens, and Weinmannia racemosa. Although found on a wide range of host plants, most collections were found on either Knightia excelsa (12) or Pseudopanax species (4).

Has previously been reported on various hosts from Central and South America, and Java (Sherwood 1980).

The pycnidia assumed to be those of the C. limitatus anamorph were found in association with the teleomorph in all collections. The pycnidia are typical in structure of Leptostroma, but all those examined were sterile. Many Rhytismataceous taxa form an anamorph and teleomorph within the same lesion, but at different times. It is not possible to identify C. limitatus unless the teleomorph state is present, as its most common host species also provide a substrate for a number of other Rhytismataceous taxa with similar anamorphs.

C. limitatus is the only species of Coccomyces found in New Zealand with ascospores less than 1.0 µm wide. It is similar to a number of the species included in the "C. leptosporus complex" described by Sherwood (1980). Species in this group which have 3-4 sided, angular ascocarps are C. tesselatus Sherwood (Thaxter 2612, on unidentified leaves, Grand Etang, Grenada, Thaxter 1912-13 - FH; Pfister 844, on unidentified leaves, Guadeloupe, Pfister, Carpenter, Sherwood, 4.1.1974 paratype - FH), C. antillarum (see specimens cited under C globosus), C philippinus (Schmidt & Kunze) Karsten (Baker, Fungi Malayana, on Neolitsea, Mt. Maquiling, Prov. Laguna, Philippines, June 1914 - type - S), and C. limitatus. C. limitatus can be separated from these other species by its very narrow asci (4-5.5 µm wide) and by its paraphyses which are broad along their entire length, rather than being swollen near the apex.

The type specimen of C limitatus has ascocarps lacking an excipulum, and asci slightly wider (5-6 µm) than those found in New Zealand collections. However the type specimen is quite small, and in all other respects, both macroscopic and microscopic, is identical to the New Zealand fungus. Other collections from South America cited by Sherwood as C. limitatus (e.g., NY-VE2112) did have narrower asci, and an excipulum developing in the same way as that described above for the New Zealand collections.