Spermogonia 15-30 µm diam., chiefly on stems, irregularly scattered, often in groups, inconspicuous, honey-coloured. Aecia on branches, petioles and veins of the leaves and fruits, confluent in large pustules up to 10 cm long, orange-yellow when fresh, surrounded by cylindric-clavate paraphyses 30-50 µm long and 10-15 µm diam. that are sometimes abundant but usually few or none. Aeciospores 18-27 x 15-20 µm, ellipsoidal to subglobose, the wall nearly or quite hyaline, 2-2.5 µm thick, finely echinulate with 6-8 indistinct pores. Uredinia hypophyllous, scattered, minute, ca 0.1 mm diam., orange, surrounded by numerous strongly incurved cylindrical paraphyses 30-50 µm long and 8-12 µm diam., sometimes slightly dilated above. Urediniospores 18-25 x I6-20 µm, obovoid to subglobose, the wall nearly or quite hyaline, 2-2.5 µm thick, closely echinulate, pores scattered, indistinct. Telia hypophyllous, scattered, very small, ca 0.1 mm diam., chestnut-brown. Teliospores 70-115 x 25-34 µm, cylindrical to obovoid-cylindrical, 6- to 8-celled, the uppermost cell rather longer, not constricted, rounded above, the apical appendage prominent, 14-16 µm long, coloured and roughened except at the apex, rounded below, chestnut-brown, the wall opaque, 3-5 µm thick, finely verrucose especially in the upper part, usually nearly or quite smooth below; pedicel 1.5 times the length of spore, colourless except near the spore, swelling in water in the lower part to 25 µm diam.
Description adapted from Wilson & Henderson (1966).