Flora of New Zealand Series

Type sp.: M. grandiflorum (Linn. f.) Hook. f. of S. America.

Fls hermaphrodite, solitary, terminal; subtending bracts 1–2, much < tepals. Tepals much > capsule, the inner shorter. Stamens 6, much < tepals. Ovary unilocular. Capsule subtrigonous. Seeds ∞, tailed at one end. Densely tufted, glab., rhizomatous perennial herbs. Stems erect, terete. Lvs few, terete. A genus of 4 spp., 3 confined to the south of S. America and 1 from N.Z.

Desvaux (J. Bot. (société de botanistes) 1, 1808, 325) stressed the importance of the ind. capsule in Rostkovia as a diagnostic character distinguishing it from Marsippospermum. Desvaux was in fact mistaken, for the Rostkovia capsule dehisces longitudinally towards the tip in the same manner as the capsule of Marsippospermum (see Hooker in Fl. Antarct. 1, 1844, 82). Bentham and Hooker (Gen. Pl. 3, 1883, 867) united Rostkovia and Marsippospermum within the one genus Rostkovia since they considered that the same degree of differences in habit, and in tailed and non-tailed seeds were to be found within the genus Juncus which has never been subdivided. Cheeseman in Man. N.Z. Fl. 1906, 721 and 1925, 290, followed Bentham and Hooker, however, Buchenau in Pflanzenr. 25, 1906, 38, Barros in Darwiniana 10, 1953, 307, and Hutchinson in Fam. Flow. Pl. 1959, 697 upheld Desvaux's two genera.