Hosts: Acaena Sanguisorbae Vahl. var. pilosa T. Kirk. On leaves. Herb. Nos. 443, 767, 768. I, III. Macraes (Otago) 600m., W. D. Reid! 28 Nov., 1921. Queenstown (Otago), 650 m., W. D. Reid! 18 Dec., 1921. (Type.) Acaena Sanguisorbae Vahl. Herb. No. 769. I, III. Table Bay, Wakatipu (Otago), 850 m., W. D. Reid ! 23 May, 1922.

0. Spermogones hypophyllous, sparse, scattered, pallid yellow.
I. Caeomata hypophyllous, sparse, scattered, orbicular, 0.5-3 mm. diam., pulverulent, orange; encircled by a dense layer of hyaline, clavate, incurved, persistent paraphyses. Spores subglobose, 18-22 mmm.; epispore hyaline, densely and closely verrucose, 1.5-2 mmm. thick, cell-contents vacuolate, orange.
III. Teleutosori hypophyllous, scattered, elliptical, up to 2 mm. long, pulverulent, greyish-black, containing very many spores in each sorus. Spores 5-7-celled, commonly 6, oblong-terete, 57-70 X 22-30 mmm.; apex rounded, not thickened, often crowned with a prominent, tinted, smooth papilla, not continuous with the upper cell-wall, up to 10 mmm. long, base rounded, spore markedly narrowed above and below; not constricted at the septa; wall chestnut-brown, 3-5 mmm. thick, sparsely and coarsely warted, warts hyaline, unequally distributed; pedicel persistent, continuous with the spore, tinted above, hyaline below, stout, up to 100 mmm. long, 6-10 mmm. thick, hollow, swollen to 18 mmm. at base, lower half closely and minutely verruculose; germ-pores 2-3 in each cell, obscure.

0. Spermagoniis hypophyllis, sparsis, raris, flavidulis. I. Caeomatiis hypophyllis, sparsis, raris, rotundis, ad 0.5-3 mm. latis, pulverulentibus, flavis; paraphysibus hyalinis incurvatis clavatis cinctis. Caeomatosporis subglobosis, 18-22 mmm. latis; episporio hyalino, solide tenuiter verrucoso, 1.5-2 mmm. crasso, contentu vacuolato, luteo. III. Sons teleutosporiferis hypophyllis, raris, ellipticis, ad 2 mm. longis, pulverulentibus, glauco-nigris, in soris sporis numerosis. Teleutosporis 5-7-cellulo, communiter 6, oblongo-teretis, 57-70 X 22-30 mmm.; apice rotundato, non incrassato, saepe prominente tincto papilloso coronato, ad 10 mmm. longis, basi rotundato, basi vel apice fortiter attenuato; ad septa non constrictis; episporio castaneo, 3-5 mmm. crasso, sparse rusticeque verrucoso; pedicello persistente, hyalino, apice tincto, crasso, ad 100 mmm. longis, 6-10 mmm. crasso; fistuloso, basi 18 mmm. inflato, verruculoso; foramine germinis ad cellulo 2-3, obscuro.

The host species A. Sanguisorbae is indigenous and widespread; it occurs also in Australia, Tasmania, and Tristan d'Acunha; the variety pilosa is endemic, and is not uncommon. (Cheeseman, 1906, p. 131.)
This species somewhat resembles Phr. Sanguisorbae Schroet. (fig. 91), but differs in the differently-shaped, broader teleutospores, in there being 5-7 cells in the spore instead of 2-5, and in the much longer pedicels. The teleutosorus characters, too, are quite different.
This species serves as a connecting-link between Phr. Acaenae and Phr. Sanguisorbae; and, of the New Zealand species, one would imagine the ancestral form to have been of the Phr. Sanguisorbae type, from which arose in succession Phr. subsimile, Phr. Acaenae, and finally Phr. novae-zelandiae. Phr. Potentillae, on the other hand, would appear to have arisen from a different form, as it has not the same general resemblance to the three species discussed above. Dr. Cockayne informs me that the hosts readily hybridize; and that the so-called species A. Sanguisorbae is in reality a composite species. This would partly account for the fact that on this species as many as three species of Phragmidium occur, whereas on other well-defined host species, and even varieties, one rust only is found.
I am indebted to Dr. Grove for specimens of Phr.Sanguisorbae, from which fig. 91 has been drawn.

Hab.: In foliis vivis Acaenae Sanguisorbae Vahl. et A. Sanguisorbae Vahl. var. pilosae T. Kirk. Queenstown, Otago, New Zealand, 650 m. W. D. Reid.

Records show this rust to occur only in Wellington Province in the North Island but to be common throughout the South Island. It is an indigenous rust species occurring only on indigenous host species [Acaena spp.].