creeping yellow cress
Tall herb, up to 70 cm tall, with various shaped leaves, lobed, with 2 to 5 pairs of leaflets, the uppermost with very narrow segments with coarsely toothed margins, flowers are yellow c. 5 mm across in large flower heads at the top of the stem.
Vascular – Exotic
Herbs - Dicotyledons other than Composites
The National Vegetation Survey (NVS) Databank is a physical archive and electronic databank containing records of over 94,000 vegetation survey plots - including data from over 19,000 permanent plots. NVS maintains a standard set of species code abbreviations that correspond to standard scientific plant names from the Ngä Tipu o Aotearoa - New Zealand Plants database.
Locally common in both islands.
Margins of water bodies and cultivation and wet pasture weed.
Glabrous perennial rhizomatous herb. Stems erect, often flexuous, 30-70 cm tall. Lvs variable in shape; margins toothed. Rosette lvs petiolate, auriculate at base, deeply pinnatifid, 4-10-(25) × 2-4 cm. Middle and upper lvs smaller, 1-2-pinnatifid, linear to ovate; lobes narrow-lanceolate to linear, entire or toothed; basal auricles present. Pedicels erecto-patent at flowering, spreading at fruiting, 5-15 mm long. Sepals 2-2.5 mm long. Petals yellow, (3)-4-5 mm long. Silique glabrous, linear, curved, 10-15 × 1-1.5 mm, but often not or poorly developed; valves with median vein weak or 0; style c. 0.5 mm long. Seeds brown, c. 0.6 mm long, finely colliculate, in 2 rows per locule.
Similar to the introduced tall yellow cress (R. amphibia) and the native ponui (R. palustris) but petals being > 2x length of the petals (unlike ponui) and fruit being sausage shaped rather than oval with peduncles < 2x the length of the fruit (unlike tall yellow cress).
October to March
November to March
Seed and rhizomes dispersed by water or contaminated machinery.
Reason for introduction
Unknown, seed or soil contaminant
Can be controlled manually, mechanically or herbicidally depending on situation.
rorippa: A latinized form of Rorippen, a Saxon vernacular name used by Euricius Cordus
Factsheet prepared by Paul Champion and Deborah Hofstra (NIWA). Features description from Webb et al. (1988).
References and further reading
Webb, C.J.; Sykes, W.R.; Garnock-Jones, P.J. (1988). Flora of New Zealand Volume 4: Naturalised pteridophytes, gymnosperms, dicotyledons. Botany Division, DSIR, Christchurch.
Popay et al (2010). An illustrated guide to common weeds of New Zealand, third edition. NZ Plant Protection Society Inc, 416pp.
Johnson PN, Brooke PA (1989). Wetland plants in New Zealand. DSIR Field Guide, DSIR Publishing, Wellington. 319pp.