Habitat: Parasitic upon Aecidium otagense Linds. on Clematis Colensoi Hook. f. Miramar (Wellington), 20 m., J. W. Bird! 5 Nov., 1920.

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.

Distribution : Europe.

This fungus is conspicuous owing to the powdery nature of the spore-masses, 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 - 4.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.

Parasitic on stems and roots of (1) Beta vulgaris, Canterbury, Ladbrooks, Jul 1956, H. C. Smith, 19069; (2) Daucus caroita. Otago, Dunedin, Jun 1954, A, G. Kenelley, 13239: (3) D. carota, Waitati, Jul 1958, A.G. K., 18501; (4) Solanum tuberosum, Auckland, Pukekohe, Oct 1961, J. M. Dingley, 21857.

Fructifications arid, encrusting, indeterminate, purplish, violet or reddish brown when fresh, often pruinose at maturity, frequently losing violet tints when dry; margins pallid, byssoid. Internal hyphae dark red-or purple-brown, septate, 5-7-(9.5) µm. diam., clamp connections absent. Probasidia subclavate to clavate, straight or tortuous, 18-26 x 6-8 µm., soon collapsing. Metabasidia cylindrical, at first straight, becoming recurved apically, typically transversely 3-septate, 52-69 x 6-8 µm; sterigmata 2-4 per basidium, subulate, to 40 x 3-4 µm Basidiospores ovate, oblong-elliptical, or occasionally curved-cylindrical, hyaline, bluntly apiculate, 9.9-13-(14.5) x 5-6.5-(7.5) µm. Germination not observed.

Plant debris or encrusting living plants.

Buddin & Wakefield, Trans. Br. mycol. Soc. 12: pi. II, f. 1-8. pl. 12, f. 13-30. 1927.

Present information suggests that violet root rot, caused by Helicobasidium brebissonii, is not an important disease of field crops in New Zealand. The species was first recorded in the country by Kirk (1907) as Rhizoctonia violacea.

TYPE LOCALITY: Northern France.