Watercress

Nasturtium officinale

Non-Native

USDA, NRCS. 2018. The PLANTS Database (http://plants.usda.gov, 28 March 2018). National Plant Data Team, Greensboro, NC 27401-4901 USA.
Illustration: USDA-NRCS PLANTS Database / Britton, N.L., and A. Brown. 1913. An illustrated flora of the northern United States, Canada and the British Possessions. 3 vols. Charles Scribner’s Sons, New York. Vol. 2: 162.

What is Watercress?

Physical Characteristics

Leaves:

• Older leaves compound
• Young leaves simple
• 1.57- 1.72 inches long

Leaflets:

• 3-11 leaflets
• Oval or sword shaped

Flowers:

• 4 white petals
• Above water
• Clustered on end of stems
• 0.12-0.2 inches long

Fruit:

• Thin
• Cylinder shaped
• Slightly curving
• 0.4-1.0 inches long

Seeds:

• About 0.04 inches long
• Round
• Found in seed pods
• Arranged in rows

Stem:

• Fleshy
• 3.9-23.62 inches long
• Easily breakable

Roots:

• Stringy
• Thin
• Rooting at nodes

Where Does it Grow?

Non-Native

Watercress can be found in streams and shallow water.

Is it Invasive?

Watercress is non-native to North America. It is an aggressive invader that out-competes the native vegetation for vital resources.

Pros and Cons of Watercress

Although, watercress is non-native, it is a food source for ducks, muskrats, and deer. Many people often use watercress as a peppery seasoning in their food.

This plant is not native to North America, but has naturalized in much of the United States. While it is not illegal to possess this plant in Texas, it should not be introduced into new water bodies and should be treated with herbicide when present.