Appendix: Fungi Parasitic Upon the Uredinales. In the past numerous fungi belonging to the following genera have been recorded as parasitizing the various spore-forms of the Uredinales :— Phycomycetes: Olpidium (= Olipidiella). Ascomycetes: Mycosphaerella (= Sphaerella). Fungi Imperfecti: Sphaeropsidales—Phyllosticta; Ascochyta; Darluca. Hyphomycetes—Cladosporium; Fusarium; Fusoma; Macrosporium; Oospora; Ramularia; Tuberculina. Doubtless many of these will later prove to be merely saprophytic, their contiguity with a rust upon the same host-plant leading to the belief that they were parasitic upon the rust. So far only the two species described below have been collected in New Zealand; Darluca is exceedingly common, especially on the uredosori of many of our rusts, but Tuberculina has been collected once only. Both species are included under the Fungi Imperfecti, the former belonging to the Sphaeropsidales (Sphaerioidaceae-Hyalodidymae), the latter to the Hyphomycetes (Tuberculariaceae-Amerosporae). Darluca Castagne. Cast., Cat. Pl. Mus. Suppl., p. 53, 1851. Pycnidia free, superficial, depressed, or conico-globose, obsoletely papillate, ostiolate, black; context of closely-woven thick-walled coloured hyphae. Spores (conidia) 1-septate, hyaline, elliptic-oblong or fusoid, muticate; borne singly on simple unbranched pedicels.

Habitat: Parasitic upon the spermogones, aecidia, uredosori, and teleutosori of numerous Uredinales; saprophytic upon the leaves of deciduous plants. Distribution: Europe; North and South America; Africa; Ceylon; Japan; Australia. Although eight species have been described, only one has been collected here. It is probable that many of these so-called species are but variable forms of D. Filum, as in many instances they appear to have been erected on slight differences in the size of the spores, a character too variable to be considered specific; for, as is shown below, in D. Filum alone the spores on different hosts range in length from 10 to 18 mmm.; furthermore, this variation may be seen in the spores from a single pycnidium. 1. Darluca Filum Castagne. (Text-fig. 126, and Plate 2 fig. 5.)  Uredinales. Cast., l.c. Sphaeria Filum Biv.-Bern., Bernh. Stirp. rar Sic. Manip., vol. 3, p. 12, 1815. Phoma Filum Fr., Syst. Myc., vol. 2, p. 547, 1823. Pycnidia superficial or immersed, scattered or gregarious, conicoglobose, elliptical, obovate, or depressed-globose, 90–120 × 60–100 mmm. diam., ostiolate, smooth, black. Conidia 1-septate, hyaline, fusoid, smooth, 10–18 × 3–6 mmm., slightly or not constricted at the septum, muticate. Habitat: Parasitic upon the spores of the following species: Uromyces otakou G. H. Cunn. (II); U. Polygoni Fcl. (II); Uromycladium alpinum McAlp. (II); Urom. notabile McAlp. (II); Urom. Tepperianum (Sacc.) McAlp. (III); Puccinia Caricis Schroet. (II, III); P. Chrysanthemi Roze (II); P. Coprosmae Cke. (III); P. Elymi Westnd. (II); P. Hoheriae Wakef. (III); P. Hydrocotyles Cke. (II); P. juncophila Cke. et Mass. (II); P. Morrisoni McAlp. (II); P. Plagianthi McAlp. (III); P. Poarum Niels. (II); P. pulverulenta Grev. (II); P. punctata Link. (II); P. whakatipu G. H. Cunn. (II); P. Unciniarum Diet. et Neg. (II, III); Phragmidium novae-zelandiae G. H. Cunn. (I); Phr. Potentillae P. Karst. (I, II); Fig. 1.—Phragmidium Acaenae G. H. Cunn. Caeomata and teleutosori from Acaena microphylla Hook. f. Arrows point to the minute teleutosori. Fig. 2.—Phragmidium norae-zelandiae G. H. Conn. Teleutosori from Acaena novae-zelandiae T. Kirk. Fig. 3.—Phragmidium Potentillae P. Karst. Teleutosori on Acaena Sanguisorbae Vahl. Fig. 4.—Hamaspora acutissima Syd. Teleutosori on Rubus australis Forst. f. Note the long and much-entwined fibrils. Arrow points to sori from which the fibrils have disappeared. Fig. 5.—Milesina Histiopteridis G. H. Cunn. Uredosori on Histiopteris incisa (Thunb.) J. Sm. The white spots consist of numerous uredospores which have exuded from the immersed peridia. Fig. 6.—Melampsora Lini Desmaz. Teleutosori on Linum monogynum Forst. Fig. 7.—Aecidium Milleri G. H. Cunn. on Aristotelia serrata (Forst.) Oliver. Fig. 8.—Aecidium Ranunculacearum DC. on Ranunculus Lyallii Hook. f. Fig. 9.—Aecidium hupiro G. H. Cunn. on Coprosma foetidissima Forst. Fig. 10.—Aecidium kowhai G. H. Cunn. on Edwardsia tetraptera (J. Mill.) Oliver. Photo by E. Bruce Levy. Fig. 11.—Aecidium Myopori G. H. Cunn. on Myoporum laetum Forst. f. Natural size. All photographs, with the exception of fig. 10, by the writer.

Aecidium otagense Linds.; A. Ranunculacearum DC.; Uredo Dianellae Diet.; U. karetu G. H. Cunn.; U. Phormii G. H. Cunn.; U. Scirpi-nodosi McAlp.; U. toetoe G. H. Cunn. Distribution: Europe; North and South America; Ceylon; Japan; Africa; Australia. From the foregoing it will be seen that in New Zealand this species has been collected on aecidia, caeomata, uredosori, and teleutosori. The mycelium ramifies through the sori and appears to plasmolyze and disintegrate those spores with which the hyphae come in contact; in certain sori, indeed, it is difficult to obtain any unaffected spores. Generally the pycnidia are superficial and easily seen, but in certain cases, particularly when they are parasitic upon aecidia, they are almost competely immersed, and their presence noted only when sections of the aecidia are examined. Saccardo (Syll. Fung., vol. 3, p. 410, 1884) states that the spores have on either end a few fine bristles; I have failed to observe these, although I have examined numerous microtome sections of pycnidia of all ages. So common are the pycnidia on certain species that they have frequently been mistaken for spermogones, and described as such. Tuberculina Saccardo. Sacc., Mich., vol. 2, p. 34, 1880. Uredinula Speg., Anal. Soc. Cientif. Argent., p. 213, 1880. Cordalia Gobi, Mem. Acad. Imp. Sci. St. Petersburg, vol. 32, p. 13, 1885. Sporodochia plane or flattened-discoid, pulverulent, formed of closely compacted upright conidiophores, which are simple and unbranched. Spores (conidia) innate, unicellular, hyaline, smooth, subglobose. Habitat: Parasitic upon the aecidia, uredosori, and teleutosori of Uredinales. Fig. 1.—Aecidium Macrodontae G. H. Cunn. on Olearia macerodonta Baker. Fig. 2.—Aecidium Clemisiae-discoloris G. H. Cunn. on Celmisia discolor Hook. f. Fig. 3.—Aecidium Celmisiae-petiolatae G. H. Cunn. on Celmisia petiolata Hook. f. The aecidia are covered by the tomentum of the leaf, and in the photograph appear as slightly-raised linear blisters, principally to the right of the midrib. Fig. 4.—Aecidium Celmisiae-Petriei G. H. Cunn. on Celmisia Petriei Cheesem. On the right of the midrib the groups of aecidia are covered by the tomentum, on the left the tomentum has been stripped off and the distorted peridia and spore-masses exposed. Fig. 5.—Darluca Filum Cast. on Uredo Scirpi-nodosi McAlp. Uredosori on the left, parasitized sori on the right. Fig. 6.—Uredo southlandicus G. H. Cunn. on Olearia angustifolia Hook. f. Note the characteristic epiphyllous, bullate, scattered sori. Fig. 7.—Puccinia namua G. H. Cunn. Aecidia on Anisotome filifolia (Hook. f.) Cockayne and Laing. Fig. 8.—Tuberculina persicina Sacc. on Aecidium otagense Linds. Note the flattened sporodochia surrounded by the ruptured epidermis. Fig. 9.—Coleosporium Fuchsiae Cke. Uredosori on leaves of seedlings of Fuchsia excorticata (Forst. f.) L. f. Natural size. Photographs by the writer. All photographs are taken from dried herbarium material.

Distribution: Europe; South America. Although twenty species have been described, I doubt whether more than a third of this number are valid, as, judging from the published descriptions, most appear to have been separated on host-distinctions alone. 1. Tuberculina persicina Saccardo. (Text-fig. 127, and Plate 2 fig. 8.) Sacc., Fung. Ital., tab. 964, 1881. Tubercularia persicina Ditm., Sturm. Deutsch. Fl., vol. 1, p. 99, 1817. Caeoma fallax Cda., Icon., vol. 5, p. 49, 1842. Uredo lilicina Rob., in Desm., Ann. Sci. Nat., ser. 8, vol. 3, p. 11, 1847. Cordalia persicina Gobi, Mem. Acad. Sci. Imp. St. Petersburg, vol. 32, p. 18, 1885. Sporodochia discoid. 0.1–1.25 mm. diam., immersed, surface alone showing, pulverulent, consisting of closely compacted tinted hyphae, 25–80 mmm. long, 2–5 mmm. thick. Conidia unicellular, globose, or shortly elliptical, 7–14 mmm. diam., epispore smooth, tinted dingy-violet or violet-brown, 1 mmm. thick. Habitat: Parasitic upon Aecidium otagense Linds. on Clematis Colensoi Hook. f. Miramar (Wellington), 20 m., J. W. Bird! 5 Nov., 1920. Distribution: Europe. This fungus is conspicuous owing to the powdery nature of the sporemasses, and the purple colour of the spores and sporodochia. These are plano-discoid in shape, and are surrounded by the ruptured epidermis and partly disintegrated peridia of the aecidia; the conidiophores are closely packed together, and somewhat resemble the hymenium of Stereum or some similar Basidiomycete. On their apices are borne the spores, which, owing to the method of production, frequently occur in chains. In the specimens at hand the parasite is seen frequently to infect the aecidia before they appear on the surface—i.e., before they dehisce—as when sections are examined aecidia in different stages of development may be seen in all stages of infection. But by far the greater number of parasitized aecidia appear to have been infected after they have expanded, since the sporidochia of the parasite are frequently seen to be partially surrounded by portions of the revolute margins, which give a very ragged appearance to the shoots of Clematis upon which the aecidia are located. Considerable confusion has arisen in the past as to the systematic position of Tuberculina, and in many systematic papers it has been placed under the Ustilaginaceae; in fact, certain authors state that on germination the spores give rise to promycelia [basidia] bearing sickle-shaped conidia [basidiospores]. This is not the case, however, for I have germinated the spores and find they produce long and slender hyphae. I have little doubt but that the so-called aecidium described and figured by Plowright (1899, p. 161) as occurring in the cycle of Puccinia Vincae Berk. is this species. He states that the spores are finely echinulate; but Grove (1913, p. 177), in a discussion of this so-called aecidium, states that they are smooth. Grove states that the organism in question is not an aecidum, and suggests that it may be a parasite; his description agrees closely with T. persicina, differing only in colour, which is stated to be dark-brown with a greyish bloom. Grove also mentions that both Sydow (1904, p. 338) and Fischer (1904, p. 167) considered the sporidochia on Puccinia Vincae to be primary uredosori.

It is worthy of mention that the larva of a dipterous insect, Cecidomyia uredinicola, also parasitizes the spores of many of our species of Uromyces, Puccinia, &c. The larva is about 3 mm. in length, and is conspicuous on account of its bright reddish-orange colour. It feeds only on the spores.