Host: Sonchus oleraceus L. On leaves and stems. Herb. No 281. II, III. Palmerston North (Wellington), 300 m., G. H. C. 14 June, 1919.

0. Spermogones amphigenous, scattered, sparse, associated with the uredosori.
II. Uredosori amphigenous and caulicolous, scattered, or more commonly in small orbicular or elliptical groups of 3-5 sori, 1-3 mm. long, seated on discoloured spots, orbicular, 0.25-1 mm. diam., on stems elliptical, confluent, and up to 5 mm. long, bullate, immersed, partly covered by the epidermis, yellow, opening by an irregular apical pore, encircled by a single layer of thick-walled chestnut-brown paraphyses. Spores elliptical or obovate, 30-42 X 20-24 mmm.; epispore hyaline, densely and finely verrucose, 3-4 mmm. thick, cell-contents yellowish, oily; germ-pores indistinct.
III. Teleutosori hypophyllous, scattered or confluent; seated on discoloured spots, bullate, dark chestnut-brown, orbicular or irregular, up to 2 mm. diam., compact, long covered by the epidermis; encircled by a single layer of chestnut-brown clavate paraphyses. Spores elliptical or subclavate, 50-60 X 24-31 mmm.; apex rounded or bluntly acuminate, thickened up to 6 mmm., base attenuate, frequently rounded, lower cell slightly narrower; not or slightly constricted at the septum: epispore smooth, pallid chestnut-brown, 1.5-2 mmm. thick, cell-contents granular; pedicel persistent, tinted brown, up to 38 X 8 mmm.; germ-pore of the upper cell apical or slightly oblique, conspicuous, basal pore immediately beneath the septum, conspicuous.
X. Mesospores not uncommon, subclavate or obovate, up to 53 mmm. long.

Distribution: Western Europe; Algeria; Canaries; Japan; Ceylon.

The host is introduced.
Grove (1913, p. 156) states that the paraphyses of the uredosori are in reality the upper part of an imperfect peridium; at the top these cells become elongated and parallel, they are at first hyaline, but finally become dark brown and irregular in shape. This peculiar feature, and the immersed character, has led systematists to confuse it with an aecidium, but, as the uredospores are borne singly on pedicels, no such confusion should arise. In the specimens at hand a few teleutospores are present in the uredosori.