Identify An Aquatic Weed

• Free-floating perennial, sometimes rooted in mud
• Shiny leaves and spongy stalks
• Lavender to white flowers with a yellow “eye-spot”
• When non-flowering and intermediate-aged, can be confused with South American spongeplant
• Native to South America

Spring - late fall; flowers June - October

Habitat
Ponds, sloughs, channels, canals, streams, rivers, lakes

Control Methods Currently
Used By DBW:
Herbicide, Mechanical Removal, Hand Removal

• Floating to emergent perennial
• Leaves and stems creep onto land, float on the water surface, or grow upright; upright stems are slightly hairy
• Oval-shaped (younger) to willow-like (more mature) leaves
• Bright, showy yellow flowers
• Native to South America

Spring - late fall; flowers May - December

Habitat
Slow-flowing rivers, lake and reservoir margins, and in the shallow waters of canals and floodplains

Control Methods Currently
Used By DBW:
Herbicide, Mechanical Removal

• Floating to rooted perennial
• Thick, spongy, floating ovate to spatula-shaped leaves; honeycomb-like spongy tissue on lower surfaces
• Juveniles develop into mature clumps up to 50 cm (~20 in) tall
• Small white flowers
• More mature plants can be confused with water hyacinth
• Native to Central and South America

Spring - late fall; flowers June - September

Habitat
Ponds, sloughs, channels, canals, streams, lakes

Control Methods Currently
Used By DBW:
Herbicide, Mechanical Removal, Hand Removal

• Aquatic to terrestrial perennial
• Aquatic form has hollow stems above and below the water, while terrestrial form has solid stems
• Lance-like to oval-like leaves that narrow at the base
• Leaves have distinctive midrib
• Pleasantly fragrant pearly white flowers
• Can be confused with water primrose when not in bloom
• Native to South America

Rapid growth in summer, survives cold winters without long periods of frost; flowers June - October

Habitat
Shallow water in ditches, marshes, pond margins, and slow-moving waterways. May also be found terrestrially in wet soils

• Completely submersed with rooths anchored in the soil
• 3-6 leaves in a whorled arrangement
• Middle and upper leaves are between 15-40 mm (~0.50-1.50 in) long and 2-5 mm (~0.10-0.25 in) wide
• Small white flowers that extend up to 3 cm (~1.25 in) above the water surface
• Native to South America

Spring - late fall; flowers June - October

Habitat
Slow-flowing or still water in sloughs, canals, river, ponds, lakes, reservoirs; often in nutrient-rich substrates

Control Methods Currently
Used By DBW:
Herbicide

• Leaves are floating and/or submersed
• Wavy, stiff, crinkled leaves between 50-76 mm (~2-3 in)
• Develop turions, or specialized stem buds that survive unfavorable conditions
• Turions resemble brown pinecones between 7-25 mm (~0.25- 1 in) long
• Native to Eurasia

Early spring - late summer; flowers May - September

Habitat
Ponds, lakes, streams, rivers, reservoirs, irrigation ditches, marsh area

Control Methods Currently
Used By DBW:
Herbicide

• Perennial with creeping underground stems; typically submersed, sometimes emergent leaves while flowering
• Finely divided, whorled leaves with more than 12 leaflet pairs
• Uniform, parallel, acutely-angled leaf segments
• Stems and growing tips often red-tinged
• Does not develop turions, or specialized stem buds that survive unfavorable conditions
• Small, pinkish, whorled emergent flowers
• Native to Eurasia and northern Africa

Spring - fall; flowers June - September; plants can die back in winter or remain green

Habitat
Ponds, lakes, rivers, streams, canals, ditches

Control Methods Currently
Used By DBW:
Herbicide

• Submersed annual to perennial with firm, forked, toothed,
  olive-green to dark green bottlebrush-like leaves
• Stems up to 2.5 m (~8.2 feet) long
• Plants lack roots, and are free-floating or anchored by
  specialized buried stems
• Turions that consist of clusters of scale-like leaves at stem tips
• Small, inconspicuous, water-pollinated flowers
• Native to California

Germinates in spring, slow growth through winter; flowers June - October

Habitat
Ponds, slow-flowing streams, ditches

Control Methods Currently
Used By DBW:
Herbicide

• Submersed, rooted to free-floating perennial, but can have floating leaves while flowering
• Opposite leaves on short stalks without toothed margins
• Finely divided, red to green fan-shaped leaves
• Floating leaves are 1-3 cm (~0.40-1.25 in) long
• Small white to pink to purplish flowers extend above the water surface
• Introduced from the Eastern United States

Spring - early fall, flowers May - September

Habitat
Ponds, slow-flowing streams, ditches

Control Methods Currently
Used By DBW:
Herbicide

• Floating to terrestrial perennial with branched, creeping stems
• Bare, fleshy, round to kidney-shaped leaves with 3-7 lobes
• Stalk attaches to the base of the leaf at the margin, unlike other native pennywort species with stalks that attach to the center of the leaf’s underside
• Shorter flower clusters of 5-10 flowers with greenish- to yellowish-white to purplish petals
• Native to North America

Habitat
Pond and lake margins, marshes, low swamps, slow streams, irrigation and drainage ditches