Descriptions of New Species of Scirpus. By Varner J. Cook. [Read before the Auckland Institute, August 21, 1946; received by Editor, August 29, 1946; issued separately, September, 1947.] Scirpus maritimus L. was included by Raoul (Choix de Plantes de La Nouvelle-Zelande, 1846, p. 40) in his enumeration of the plants occurring in New Zealand. Hooker (Flora Novae-Zelandiae, 1853, p. 268) also records S. maritimus L. as being abundant in the North and South Islands, collected by Colenso and others. In his Handbook of the New Zealand Flora (1864, p. 300) Hooker states the species was collected by Banks and Solander. Cheeseman (Manual of the Flora of N.Z., 1906, p. 778) records the New Zealand forms he places under S. maritimus L. as belonging to the varieties fluviatilis Torr and macrostachya Michx. He states “according to Mr. C. B. Clarke, the typical form of the species has not yet been observed in Australia or New Zealand.” All the species labelled by Cheeseman in various herbaria bear one or other of the varietal names, but it is not clear whether he accepts C. B. Clarke's view or not. Subsequent revision of the Scirpus species, including the varieties above has resulted in the latter being elevated to the rank of species var. macrostachya being now Scirpus robustus Pursh (Fl. Am. Sept. 56, 1814) and var. fluviatilis is now Scirpus fluviatilis (Torr) A. Gray (Man. Bot. 527, 1848), and these names have accordingly been applied to the N.Z. plants. A study of the N.Z. specimens reveals, however, that three species are involved and further, a comparison of these species with N. American S. robustus Pursh and S. fluviatilis (Torr) A. Gray, and with allied species shows that they differ materially. The latter is a stouter plant with large spikelets and a much larger achene. S. robustus Pursh is also larger than the N.Z. plant bearing that name and has a very different achene. Our plant resembles Scirpus paludosus Nels. but again the achene is different. The species described below as a third N.Z. species, having hitherto been confused with the above species, resembles Scirpus robustus Pursh, but the fruits are quite different. A comparison of the achenes of the above species and also of Scirpus maritimus L. may be made from the drawings accompanying this paper. The N.Z. plants are distinct from Scirpus maritimus L., Scirpus fluviatilis (Torr) A. Gray, and Scirpus robustus Pursh, and their descriptions as new species are as follows:— Measurements of stems and leaves about mid-point. Measurements of spikelets when in fruit. Flowering spikelets are narrower and those of pressed specimens broader. It has to be noticed that in the above species the leaves become narrower as they ascend the stem, which also tapers. The measurements given are of leaves at about the mid-point of the stem.