Flora of New Zealand Series

Tall-growing, loosely tufted or forming patches, stems occasionally in lines; rhizomes stout, far-extending. Stems 50-120 cm high, with 1-2 cauline leaves, internal transverse septa not present. Leaves hollow with longitudinal and transverse septa (in the recent N.Z. collections the longitudinal septa were not evident); cauline leaves with 35-60 evident transverse septa. Inflorescence to 15cm long, open, spreading and diffuse, with many small, 3-12-flowered clusters, secondary branches diverging at a wide angle (i.e. greater than 90º) or curved. Tepals c.2 mm long, blunt and incurved, hooded. Stamens 6. Capsule 2-2.5 mm long, scarcely > tepals, ovoid, trigonous, acuminate, short-beaked.

S. Canterbury - Lake Ellesmere (1868), New Brighton (1893); Otago - Lake Waihola (1891), Cromwell (undated); refound in Canterbury by R. Mason at Waiau River (1962) and New Brighton (1970). (Europe, N. Africa, N. America)

First record: Petrie 1894: 273, as J. obtusiflorus Ehrhart.

First collection: Lake Ellesmere, J. B. Armstrong, 1868 (CHBG).

J. subnodulosus resembles J. acutiflorus in the tall stems and stout, far-extending rhizomes, but is recognised by the widely diverging, often down-turned secondary branches of the large open heads, the blunt hooded tepals, and the flowering stems below the heads lacking transverse septa.