Cardamine flexuosa
(wavy bittercress)

Preferred Common Name

• wavy bittercress

Other Scientific Names

• Barbarea arisanensis (Hayata) S.S.Ying
• Cardamine arisanensis Hayata
• Cardamine decurrens Zoll. & Moritzi
• Cardamine drymeja Schur
• Cardamine duraniensis Revel ex Des Moul.
• Cardamine hamiltonii G.Don
• Cardamine konaensis H.St.John
• Cardamine muscosa Vahl ex DC.
• Cardamine nasturtioides D.Don
• Cardamine occulta Hornem.
• Cardamine setigera Tausch
• Cardamine sylvatica Link
• Cardamine zollingeri Turcz.
• Nasturtium obliquum Zoll.
• Pteroneurum decurrens Blume

International Common Names

• English: wavy-leaved bittercress; wood bittercress; woodland bittercress
• Chinese: wan qu sui mi ji

Local Common Names

• Japan: tanetsuke-bana

• Domain: Eukaryota
•     Kingdom: Plantae
•         Phylum: Spermatophyta
•             Subphylum: Angiospermae
•                 Class: Dicotyledonae
•                     Order: Capparidales
•                         Family: Brassicaceae
•                             Genus: Cardamine
•                                 Species: Cardamine flexuosa

The genus Cardamine comprises between 230 and 250 species of herbs distributed worldwide. The species Cardamine flexuosa was originally described from Great Britain and there are no doubts about its circumscription within Europe, except for occasional misidentifications as C. hirsuta. C. flexuosa is considered one of the most variable species within the family Brassicaceae, especially with respect to stem direction, plant height, density of indumentum, flower size, degree of zigzagging of the raceme rachis, orientation of fruiting pedicels and, most dramatically, number, shape, size, base (sessile vs. petiolulate) and margin of lateral leaf lobes (Lihová et al., 2006; Flora of China Editorial Committee, 2019; Flora of North America Editorial Committee, 2019).

The following is adapted from Flora of China (Flora of China Editorial Committee, 2019). Herbs annual or biennial, (6-) 10-50 cm tall, sparsely to densely hirsute basally or throughout, or glabrous. Stems erect, ascending, or decumbent, simple or branched, flexuous or straight. Basal leaves not rosulate, often withered by anthesis, petiolate; leaf blade (2-)4-10(-14) cm, lyrate; terminal lobe reniform, broadly ovate, or suborbicular, repand or 3-5-lobed; lateral lobes, (1 or) 2-6(or 7) on each side of midvein, petiolulate or subsessile, oblong, ovate, or elliptic, smaller than terminal lobe, entire, repand, crenate, or 3(-5)-lobed. Cauline leaves 3-15, including petiole (2-) 3.5-5.5(-7) cm; petiole base not auriculate; terminal lobe 3-5-lobed; lateral lobes 2-7 on each side of midvein, suborbicular, ovate, oblong, oblanceolate, or linear, similar to or slightly smaller than terminal lobe, sessile or shortly petiolulate, entire, repand, dentate, or 3(-5)-lobed. Fruiting pedicels divaricate or ascending, (5-)6-14(-17) mm, slender. Sepals oblong, 1.5-2.5 × 0.7-1 mm. Petals white, spatulate, 2.5-4(-5) × 1-1.7 mm. Stamens 6, rarely 4 and lateral pair absent; filaments 2-3 mm; anthers ovate, 0.3-0.5 mm. Ovules 18-40 per ovary. Fruit linear, (0.8-) 1.2-2.8 cm × 1-1.5 mm; valves glabrous, torulose; style 0.3-1(-1.5) mm. Seeds brown, oblong or subquadrate, 0.9-1.5 × 0.6-1 mm, narrowly margined or not.

Soil reaction

• acid
• neutral

Soil texture

• heavy
• light
• medium

Natural Dispersal

Cardamine flexuosa spreads by seeds; seed pods explode when ripe. Seeds can remain viable in the ground for up to 7 years (Varnham, 2006; ISSG, 2019).

Accidental Introduction

Cardamine flexuosa has been possibly transported as a contaminant in stores or footwear. Seeds are sticky when wet and can be easily spread adhered to clothing or animals (ISSG, 2019). On South Georgia, this species was accidentally introduced in 2000, probably by vehicles brought in during building works at King Edward Point, and has since been invading native vegetation as well as disturbed areas around the settlement. It flowers and fruits prolifically, producing viable seeds easily dispersed by humans and wildlife. It has a high invasive potential on South Georgia (Osborne et al., 2009).

In Japan, C. flexuosa is often found as an agricultural weed in paddy fields, crop fields and orchards (Kudoh et al., 1993). C. flexuosa is one of of the most prolific and costly weeds of the container nursery industry of the United States (Post et al., 2011). 

• Proved invasive outside its native range
• Has a broad native range
• Abundant in its native range
• Highly adaptable to different environments
• Is a habitat generalist
• Tolerates, or benefits from, cultivation, browsing pressure, mutilation, fire etc
• Pioneering in disturbed areas
• Tolerant of shade
• Highly mobile locally
• Benefits from human association (i.e. it is a human commensal)
• Fast growing
• Has high reproductive potential
• Gregarious
• Has propagules that can remain viable for more than one year
• Has high genetic variability

• Modification of successional patterns
• Monoculture formation
• Negatively impacts agriculture
• Reduced native biodiversity
• Threat to/ loss of native species

• Competition - monopolizing resources
• Rapid growth

• Highly likely to be transported internationally accidentally
• Difficult to identify/detect as a commodity contaminant
• Difficult to identify/detect in the field
• Difficult/costly to control

Cardamine flexuosa is grown as a medicinal plant. Leaves and roots are consumed raw or cooked (Useful Tropical Plants, 2019; Flora of China Editorial Committee, 2019).