Brassicaceae

Lake Cress

Rorippa aquatica

A rosette of soft leaves that change shape with conditions — from whole and rounded to deeply cut, sometimes on the same plant. It comes from cool North American backwaters and grows very slowly.
Light
medium–high
Difficulty
easy
Temperature
4 – 27 °C (39 – 81 °F)
Native rangeRange on the map
  • Alabama
  • Arkansas
  • District of Columbia
  • Florida
  • Georgia
  • Illinois
  • Indiana
  • Iowa
  • Kentucky
  • Louisiana
  • Maryland
  • Massachusetts
  • Michigan
  • Minnesota
  • Mississippi
  • Missouri
  • New Jersey
  • New York
  • Ohio
  • Oklahoma
  • Ontario
  • Québec
  • Tennessee
  • Texas
  • Virginia
  • Wisconsin

Tank conditions

Leaf colour
green
Plant type
stem plant
Growth rate
very slow
Tolerates light
medium – high
pH
6 – 7
Carbonate hardness
2 – 14 °dKH
General hardness
0 – 30 °dGH
Placement
foreground
Propagation
plantlets on leaves, cuttings
Grows emersed
yes

Care and keeping

Appearance

Light green leaves in a low rosette; their outline varies from a simple oval to a feather cut almost to the midrib, depending on light, temperature and how the plant was grown.

Keeping

Easy but very slow, which is exactly what makes it useful at the front of a tank: it stays where it is put for months. It wants a nutritious substrate, moderate light and cool water — warm tanks suit it least. Carbon dioxide is not needed.

Placement

The front of the tank, singly or in a small group, in an unheated or cool aquarium.

Propagation

It does most of it itself: young plants form on the leaves, drop off and root. Cuttings also take.

Fish and this plant

Matching water does not mean the fish will leave the plant alone.

Cultivars

The same plant with a different look: light, water and care are shared with the species.

Other varieties: Rorippa aquatica Topf

Scientific and other names, conservation status

Other scientific names
Cochlearia armoracia var. aquatica Eaton, Armoracia aquatica (Eaton) Wiegand, Neobeckia aquatica (Eaton) Greene, Armoracia americana, Armoracia aquatica, Armoracia aquatica capillifolia, Armoracia lacustris, Cochlearia aquatica, Cochlearia armoracia aquatica, Nasturtium lacustre, Nasturtium natans americanum, Nasturtium natans brevistylum, Neobeckia aquatica, Radicula aquatica, Rorippa americana
Rorippa aquatica
(Eaton) E.J. Palmer & Steyerm.