Hosts: Pratia macrodon Hook. f. . Kirkliston Range, Otago, 1,200 m., 1/28. G.H.C. Craigieburn Range, Canterbury, 1,800 m., 1/28. G.H.C. Mt. Trovatore, Westland, 1,300 m., 2/28. G.H.C. Pratia angulata (Forst. f.) Hook. f. Raikaia Gorge, Canterbury, 400 m., 1/28. G.H.C.

0. Pyenia in, small groups, amphigenous, flask-shaped, semierumpent.
I. Aecidia amphigenous, crowded on leaves and petioles, etiolating, orange; peridia bullate, elliptical or subglobose, 0.5-2 mm. long, at first covered by the host tissue, and opening by a narrow pore, later becoming bullate and rupturing longitudinally; composed of a few scattered cells without definite cohesion, oval, flattened, to 40 mmm. long, verruculose. Spores subglobose, 22-24 mmm: ; epispore hyaline, 2 mmm. thick, finely and densely tuberculate-areolate.

The latter host is endemic and fairly widely distributed; the former is confined to the South Island (Cheesem. 1925, p. 885). The mycelium of this species is systemic, tending to etiolate and distort infected plants, rendering them conspicuous on this account. The very imperfect peridium is absent entirely from numerous sori, so that the plant is on the border line between an aecidium and a caeoma. When present the peridium consists of a few scattered dissociated cells, imperfectly cohering, and held in, place by the epidermis; consequently this structure is seen as a rule only in young sori, before the epidermis has fissured.
McAlpine (1906, p. 149) has also commented on this fact; he records this stage on Pratia erecta Gaudich., P. pedunculata Benth., and P., platycalyx Benth., as well as on Lobelia anceps L., L. pratioides Benth., and L. purpurascens- R. Br. He places the form under Puccinia aucta Berk. et F. v. M., because Lobelia anceps is a host for both; he has not succeeded in finding both stages on the same host at the same time, however. I believe them to be distinct because in the numerous collections of the aecidium recorded above and of-Puccinia aucta, aecidia are confined to Pratia spp., teleutospores to Lobelia anceps. Further, collections of Lobelia anceps taken at all times of the year from a locality near Seatoun, have yielded only teleutospores.

Although the rust occurs in both Australia and New Zealand these host species are endemic to New Zealand; the rust is recorded only from alpine herb fields in the South Island, but the host, Pratia angulata, is widely distributed throughout New Zealand.