Flora of New Zealand Series

Glabrous perennial taprooted herb. Stems erect, to 1 m tall. Lf margins shallowly dentate. Lower lvs petiolate; petiole winged and expanded into deflexed amplexicaul lobes at base; lamina pinnatifid, (6)-10-16 × (2)-3-7 cm. Upper lvs smaller, linear to lanceolate, simple, cuneately narrowed to expanded amplexicaul base. Pedicels erecto-patent at flowering, spreading at fruiting, 5-12 mm long. Sepals 2-3 mm long. Petals white, c. = sepals. Siliques patent, linear, ± terete, 15-30 × 1-1.5 mm; valves with a weak median vein, or veins 0; style c. 2 mm long. Seeds reddish brown, c. 1 mm long, coarsely reticulate, in 1 row per locule.

N.: Northland, Auckland, Waikato, Bay of Plenty, Taranaki; S.: Marlborough; K.

Endemic

Rare and local, commonest on some northern offshore islands; open sites, apparently a pioneer on newly exposed ground (e.g., slips, burnt forest).

FL (Oct)-Dec-Jan-(Feb) (Oct)-Jan-Feb-(May).

R. divaricata was treated by Allan (1961) as R. stylosa and was referred to the Australian sp. R. gigantea by Garnock-Jones, P. J., New Zealand J. Bot. 16 : 119-122 (1978).