on Dichelachne crinita (Linne f.) Hook.f. Nelson, Ruby Bay, May 1974, D. Kelly (PDD 39790-CHR 250251) 11.
Dichelachne rara (R.Br.) Vickery Northland, Whangaruru North Head, 25.1.1972, A. E. Esler (PDD 39795-CHR 227529) II. Auckland, Waikumete, 9.X1.1976, E. H. C. McKenzie, W. S. M. Versluys & S. Bowman (PDD 35538) 11, 111 [Holotypul; same details (PDD 35537) 11; Waitakere Ranges, 12.1.1972, A. E. Esler (PDD 39675) II. Nelson, Croisilles Harbour, Dec. 1972, D. & G. C. Kelly (PDD 39793-CHR 235680) 11.
on Dichelachne sciurea (R.Br.) Hook.f. var. inaequiglumis Hack. Auckland, Mercer Bay, Waitakere Ranges, 29.XII.1977, A. E. Esler & M. L. Scott (PDD 39785-CHR 321680) 11; Waikumete, 4.X1.1976, S. Bowman & A. E. Esler (PDD 39786-CHR 310078) 11; Western Park, Auckland City, Dec. 1904, D. Petrie (PDD 39783-CHR 11033) 11. Bay of Plenty-Gisborne, Maungapohatu (PDD 39784-CHR 6243) 11, 111. Wellington, Taita, Nov. 1967, A. P. Druce (PDD 39787-CHR 179588) 11. Nelson, Whangamoa Saddle, 4.111.1947, A. J. Healy (PDD 39789-CHR 51523) 11.
on Dichelachne sp. Marlborough Sounds, Pelorus Bridge, 8.11.1961, R. F. R. McNabb (PDD 19613) II.

Aecia not known. Uredinia µmphigenous, mainly on abaxial surface, orange-yellow, pulverulent, with colourless thin-walled cylindrical paraphyses. Urediniospores (16-) 21-27 (-28) x (15-) 18-23 (-25) µm, globose or broadly ellipsoid, wall 1.25-1.75 µm thick, pale yellow, finely and closely echinulate, germ pores 8-10 (-13), scattered. Telia on abaxial surface, cinnamon-brown. Teliospores (45-) 50-65 (-80) x (15-) 17-20 (-22) µm, constricted at septum, wall 1-1.5 µm thick at sides, (5.5-) 7.5-10 (-12) µm at apex, smooth, pale chestnut-brown apically, paler basally, upper cell ellipsoidal or subglobose, lower cell obovoid; pedicles up to 20 x 6-9 µm, persistent, pale brown.

Aecia ignota. Uredinia plerumque epiphylla, lutea, pulve rulentia, paraphysibus hyalinis cylindraceis. Urediniosporae (16-) 21-27 (-28) x (15-) 18-23 (-25) µm, globosae vel late ellipsoideae, membrana 1.25-1.75 µm crassa, pallide flavida, echinulata, poris germinationis 8-10 (-13), sparsis. Telia epiphylla, cinnamomeo-brunna. Teliosporae (45-) 50-65 (-80) x (15-) 17-20 (-22) µm, ad septum constrictae, membrana ad latera 1-1.5 µm crassa, ad apicem (5.5-) 7.5-10 (-12) µm, apicaliter pallide castaneo-brunneae, basaliter pallidae, cellula apicali ellipsoidea vel sub globosa, cellula basali obovoidea; pedicello usque ad 20 x 6-9 µm, persistente, pallide brunneo. In foliis graminis speciei Dichelachne crinita (Linne f.) Hook.f., D. rara (R.Br.) Vickery, D. sciurea (R.Br.) Hook.f. var. inaequiglumis Hack. Holotypus PDD 35538.

Puccinia rara resembles P. crinitae McNabb described on Dichelachne crinita by McNabb (1962). The urediniospores of the two rusts are similar in shape, but those of P. crinitae are larger (av. 31 x 27 µm) and usually have more germ pores (10-14). The large capitate paraphyses of P. crinitae (Fig. lb) are very obvious, whereas P. rara has only small cylindrical paraphyses. The teliospores of both rusts are similar in shape and size, although the apical wall of the teliospores of P. crinitae is much narrower (up to 4 µm). Cummins (1971), who examined the type of P. crinitae, gives larger measurements for the teliospores than are given by McNabb (1962). The discrepancy is apparently due to the scarcity of teliospores on the type.
The two rusts show a difference in host range. Records to date show that P. crinitae is restricted to D. crinita (30 collections), and P. rara mainly to D. rara (5 collections) and D. sciurea var. inaeyuiglumis (6 collections), with the one exception (PDD 39790) on D. crinita.