New Zealand, leaf of Telopea sp., M. Abdelshife, 11 Sept. 1996, PREM 55350 (holotype); New Zealand, leaf of Telopea sp., M. Abdelshife, 5 Aug. 1996, BPI 806263; New Zealand, leaf of Telopea sp., M. Abdelshife, 6 Aug. 1996, BPI 806264.

Leaf spots circular, amphigenous, 1-4 mm diam., grey in centre, surrounded by a raised, dark brown border and a narrow chlorotic margin. Pseudothecia amphigenous, sparsely distributed, single, black, erumpent, globosa, up to 120µm diam.; apical papillate ostiole 5-10 µm in diam.; wall consisting of 3-4 layers of medium brown textura angularis. Asci aparaphysate, fasciculate, bitunicate, subsessile, obovoid to broadly ellipsoid or cylindrical, straight or slightly curved, 8-spored, 20-28 x 8-10 µm. Ascospores multiseriate, overlapping, hyaline, guttulate, thin-walled straight to slightly curved, fusoid-ellipsoidal with obtuse ends, widest in the middle of the apical cell, medianly 1-septate, generally not constricted at septum, with some ascospores on the leaf surface appearing slightly constricted; ascospores tapering more prominently towards the lower end (9-)10-11(-12) x (2-)2.5(-3) µm.

Pseudothecia amphigena, sparse distributa, unica, nigra, erumpentia globosa ad 120 µm diam. Asci aparaphysati fasciculati bitunicati subsessiles obovoidei ad late ellipsoidei vel cylindracei, recti vel parum curvati, 8 sporis, 20-28 x 8-10 µm. Ascosporae multiseriatae, imbricatae, hyalinae, guttulatae, parietibus tenuibus, rectae ad parum curvatae, fusoideo-ellipsoideae apicibus obtusis, latissimae in medio cellulae apicalis, mediano 1-septatae, magis prominanter ad basim contractae (9-)10-11(-12) x (2-)2.5(-3) µm.

Although no species of Mycosphaerella has been described from Telopea (Corlett 1991, 1995), three species are presently known from leaves of Protea (Proteaceae), namely M. proteae (Syd.) Arx, M. jonkershoekensis Van Wyk et al. and M. bellulus Crous and M.J Wingf. (Figures 7-9) (Crous & Wingfield 1993). Ascospores of M. telopeae are much smaller than those of the large-spored M. proteae, which measure 20-33 x 6-8 (mean = 26 x 7) µm. Morphologically ascospores of M. telopeae resemble those of M. jonkershoekensis which measure 11-23 x 4-6 (mean =18 x 4.5)µm, but ascospores of the former differ in being much smaller and less prominently constricted at the septum. Ascospores of M. telopea are slightly larger than those of M. bellulus, 7-11 x 2-3 (mean = 9 x 2.5) µm, and are not as prominently constricted as in the latter species. The erumpent black pseudothecia of M. telopea are also distinct from those of M. jonkershoekensis and M. bellulus, which are subepidermal and generally not visible to the naked eye.
When Crous and Wingfield (1993) treated the species of Mycosphaerella occurring on Protea, little was known about their behaviour in culture. Subsequent to that study, fresh collections were obtained of all three of those species. As observed in the type collection of M. jonkershoekensis (PREM 44830), ascospores from fresh collections were frequently slightly olivaceous in their asci. When ascospores are shot out for germination on MEA (Crous et al. 1991), ascospores become verruculose, brown, and constricted at the septum. Ascospores germinate initially with germ tubes growing parallel to the long axis of the spore (Figure 8). After 48 h, however, ascospores have usually formed several germ tubes, and the germination is irregular. A peculiarity about M. jonkershoekensis is that ascospores germinate at 25°C, but die soon after germination if the plates are not incubated at 15°C for one to two weeks. After this initial phase the fungus will grow at most temperatures, and it is hypothesised that this low temperature requirement is a prerequisite for successful germination and infection of leaf tissue. The same phenomenon has also recently been reported for M. juvenis Crous and M.J. Wingf. on Eucalyptus (Crous & Wingfield 1996).
Ascospores of M. bellulus germinate with one to several germ tubes which grow irregularly to the long axis of the spore. As with M. jonkershoekensis, spores darken and become verruculose at germination (Figure 7). In the present study, M. bellulus was also isolated from leaf lesions of Leucospermum spp. (STE-U 1321-1323), and it appears to be a very common species of Mycosphaerella on Protea spp., frequently also occurring in association with Leptosphaeria protearum Syd.
After several unsuccessful attempts, ascospores of M. proteae were finally induced to germinate in culture. Unlike M. jonkershoekensis and M. proteae, ascospores could never be induced to shoot out onto the agar surface, and the epidermis had to be cut open to expose the pseudothecia. This difference, as well as the distinct lesions and red-purple discolouration of the leaf tissue suggest that M. proteae is a fungus quite unrelated to the other species dealt with above. In culture, germinating ascospores become constricted at their septum, brown in colour, and germinate with one germ tube generally parallel to the long axis of the spore (Figure 9). Ascospores did not become as verruculose as those of M. bellulus and M. jonkershoekensis. Colonies were extremely slow growing, and after about 6 months at 25°C on MEA had hardly reached 5 mm in diam., suggesting that this fungus is more of an obligate pathogen than the other species of Mycosphaerella treated here.

New Zealand, leaf of Telopea sp., M. Abdelshife, 11 Sept. 1996, PREM 55350 (holotype)