Lepidium ruderale
Common names
roadside pepperweed, stink cress, narrow-leaved cress
Biostatus
Exotic
Category
Vascular
Structural class
Herbs - Dicotyledons other than Composites
Detailed description
Herbs annual or biennial, (50-)100-350(-550) mm tall, fetid, puberulent with terete papillate trichomes. Stems erect or ascending, branched above. Basal leaves with petioles 10-30 mm; leaf blade (1 or)2- or 3-pinnatisect, (15-)30-50(-60) × (5-)7-2(-25) mm, glabrous except for ciliate margin; ultimate lobes oblong, entire or rarely toothed, acute. Upper cauline leaves sessile; leaf blade linear, (4-)10-20(-30) × (0.3-)0.5-2.5(-3.5) mm, sparsely pubescent, base cuneate, not auriculate, margin usually entire, ciliate, apex obtuse to subacute. Fruiting pedicels slender, divaricate, straight or slightly curved, (1.5-)2.0-4.0(-5.0) mm, puberulent all around. Sepals oblong, 0.5-0.9(-1.0) × 0.2-0.4 mm, puberulent with papillate trichomes, margin and apex white. Petals absent, sometimes rudimentary and to 0.4 mm. Stamens 2; filaments 0.7-0.8 mm; anthers ovate, 0.1-0.2 mm. Fruit broadly elliptic, (1.5-)1.8-2.5(-3.0) × 1.5-2.0(-2.3) mm, narrowly winged apically; apical notch 0.1-0.2 mm; style to 0.1 mm, included in apical notch. Seeds brown, oblong or ovate-oblong, 1.0-1.5 × 0.6-0.7 mm, wingless, finely papillate.
Distribution
Exotic. Known in New Zealand from a few sites in Central Otago and from Invercargill, South Island
Habitat
A weedy plant of roadsides and urban wasteland
Conservation status
Not applicable
Detailed taxonomy
Family
Brassicaceae
Ecology
Flowering
May-July
Fruiting
May-July
Year naturalised
1969
Origin
Europe
Other information
Etymology
lepidium: Scale-shaped (pods)
ruderale: From the Latin ruderatum ‘rubble, waste’, meaning growing in wasteland or amongst debris
Chromosome number
2n = 16, 32
Referencing and citations
Attribution
The above description was modified from Flora of China, Vol. 8, www.eFloras.org. by P. J. de Lange 2 October 2010