GROUP 7 ID

Potamogetonaceae FAMILY

Potamogetonaceae - pondweed family
Only in freshwater and rarely in marshy areas

-- Perennial
*****Leaves Alternate or opposite and are basally sheathed Blades are floating or submerged

**Floral characteristics Small axillary spikes
Floral parts in sets of 4
Fruit and Seeds 1-4 drupelets or achenes

---- Cotyledon Can looked coiled
Stems Herbaceous Often jointed
Roots Fibrous roots with rhizomes

Potamogeton crispus

Potamogeton crispus (Potamogetonaceae)→ curlyleaf pondweed

• Perennial, submerged aquatic

• Oblong 2 –3 inch brown-green leaves are wavy along the edges, like lasagna noodles

• Leaves attach to the stem in an alternate pattern

• Secondary veins branch from a midvein in perpendicular pattern (native pondweeds have parallel leaf veins)

Potamogeton crispus: Identification

Potamogeton crispus (Potamogetonaceae)→ curlyleaf pondweed

• Flower stalks stick above the water’s surface and appear reddish-brown in color

• Plant produces small greenish brown pine cone look-a-likes called turions which sprout new plants

• Extensive root system can tolerate extreme conditions (has even been found growing under inches of snow and ice!)

Stuckenia pectinata (Potamogetonaceae)

Stuckenia pectinata (Potamogetonaceae)→ sago pondweed
• Native to North America

• Perennial, submerged aquatic

• Stems are thin, long and highly branched

• Leaves very thin and filament-like, about 1/16 in. wide and 2-12 in. long tapering to a point

• Leaves grow in thick layers, originating from a sheat

Stuckenia pectinata: Identification

Stuckenia pectinata (Potamogetonaceae)→ sago pondweed

• Fruit is nut-like 1/8 to ¼ in. long and approximately 1/8 in. wide

• Plant regrows each year from thickly matted rhizomes

• Flowering reproductive stalk is the only part of plant above the water

Hydrilla verticillata (Hydrocharitaceae)

Hydrilla verticillata (Hydrocharitaceae)→ hydrilla, waterthyme

CO LIST A

• Dioecious, perennial, submerged aquatic species.

• Female flowers consist of 3 sepals and 3 petals, white to reddish brown.

• Male flowers are inconspicuous and green.

• Reproduction by tubers, turions, seeds and stem fragments.

• Stems near the top of the water column are highly branched, forming dense mats.

Myriophyllum spicatum (Haloragaceae): 

Myriophyllum spicatum (Haloragaceae) → Eurasian watermilfoil

CO LIST B

• Rooted, submersed perennial.

• Stems are reddish brown to light pink.

• Leaves are deeply divided (feather like).

• Leaves arranged in whorls of 3-6.

• Native milfoils have <14 leaflet pairs per leaf while the non-native milfoil generally has 14 or more pairs of leaflets per leaf

Hydrilla verticillata (Hydrocharitaceae)): Identification

Hydrilla verticillata (Hydrocharitaceae)→ hydrilla, waterthyme

CO LIST A

• Dioecious, perennial, submerged aquatic species.

• Female flowers consist of 3 sepals and 3 petals, white to reddish brown.

• Male flowers are inconspicuous and green.

• Reproduction by tubers, turions, seeds and stem fragments.

• Stems near the top of the water column are highly branched, forming dense mats.

Myriophyllum spicatum (Haloragaceae): Identification

Myriophyllum spicatum (Haloragaceae) → Eurasian watermilfoil

CO LIST B

• Produces by seed, but most reproduction is accomplished through plant fragmentation and stolons.

• Flowers are produced on a spike protruding out of the water.

• Prefers lakes, ponds and other slow moving water bodies.

• Tolerates a wide range of water conditions, including high salinity levels

Ambrosia artemisiifolia (Asteraceae)

Ambrosia artemisiifolia (Asteraceae)→ common ragweed

• Native to all of mainland US and many areas of Canada

• Annual Ambrosia artemisiifolia: Identification

• Leaves deeply lobed, with hairy leaf surface

• Stems erect, branching above, with coarse hairs

• Plant can grow 1-3 ft. tall

Ambrosia artemisiifolia (Asteraceae): identification

Ambrosia artemisiifolia (Asteraceae)→ common ragweed

• Flowers greenish yellow and found on the ends of branches

• Fruits are yellowish to reddish brown, woody, spined, and ridged

• Alternate name: annual ragweed

Scorzonera laciniata (Asteraceae) → cutleaf vipergrass

Scorzonera laciniata (Asteraceae) → cutleaf vipergrass

- Biennial.- Basal leaves are deeply cut and oblanceolate

– up to 8 in. long.

- Stem leaves are smaller, entire.

- Multiple erect stems, hollow, and sparsely hairy.

Scorzonera laciniata (Asteraceae: identification)

Scorzonera laciniata (Asteraceae) → cutleaf vipergrass
- Biennial.
Reproduces by seed.
- Bright, yellow flowers, about 1-2 inches wide.
- Resemble western salsify or dandelion flower.
- Each stem has one flower.
- Basal leaves are deeply cut and oblanceolate
– up to 8 in. long.
-Stem leaves are smaller, entire.
- Multiple erect stems, hollow, and sparsely hairy

WHO IS SHE?

Scorzonera laciniata (Asteraceae) → cutleaf vipergrass

WHO IS SHE?

Potamogeton crispus (Potamogetonaceae)→ curlyleaf pondweed

WHO IS SHE?

Stuckenia pectinata (Potamogetonaceae)→ sago pondweed

WHO IS SHE?

Hydrilla verticillata (Hydrocharitaceae) → hydrilla, waterthyme

CO NOXIOUS WEED LIST A

WHO IS SHE?

Myriophyllum spicatum (Haloragaceae) → Eurasian watermilfoil
CO NOXIOUS WEED LIST B

WHO IS SHE?

Ambrosia artemisiifolia (Asteraceae)→ common ragweed 

What weeds (Group 7) are CO List A?

Hydrilla verticillata (Hydrocharitaceae) → hydrilla, waterthyme

What weeds (Group 7) are CO List B?

Myriophyllum spicatum (Haloragaceae) → Eurasian watermilfoil

What weeds (Group 7) are Native to North America?

Stuckenia pectinata (Potamogetonaceae)→ sago pondweed

Ambrosia artemisiifolia (Asteraceae) → common ragweed

WHO IS SHE?

Myriophyllum spicatum (Haloragaceae) → Eurasian watermilfoil

WHO IS SHE?

Ambrosia artemisiifolia (Asteraceae) → common ragweed

WHO IS SHE?

Scorzonera laciniata (Asteraceae) → cutleaf vipergrass 

WHO IS SHE?

Potamogeton crispus (Potamogetonaceae) → curlyleaf pondweed

WHO IS SHE? 

Stuckenia pectinata (Potamogetonaceae) → sago pondweed

WHO IS SHE? 

Hydrilla verticillata (Hydrocharitaceae) - hydrilla, waterthyme
CO NOXIOUS WEED LIST A

WHO AM I?
• Native to Eurasia
• Forms dense mats in the water, which can seriously impact water quality when they die off
• Can alter the nutritional dynamics of a fertile lake causing heavy summer algae blooms
• Highly adaptable to different locations and sediment types; can tolerate extreme conditions

• Flower stalks stick above the water’s surface and appear reddish-brown in color

• Plant produces small greenish brown pine cone look-a-likes called turions which sprout new plants

• Extensive root system can tolerate extreme conditions (has even been found growing under inches of snow and ice!)

Potamogeton crispus (Potamogetonaceae)→ curlyleaf pondweed

WHO AM I?

• Native to North America
• Submerged portions of the plant provides habitat for many micro and macro invertebrates; those invertebrates are then used as food for fish and many waterfowl
•Can become problematic when dense stands form in recreational waters and irrigation canal

• Perennial, submerged aquatic

• Stems are thin, long and highly branched

• Leaves very thin and filament-like, about 1/16 in. wide and 2-12 in. long tapering to a point

• Leaves grow in thick layers, originating from a sheat

Stuckenia pectinata (Potamogetonaceae) → sago pondweed

WHO AM I?

• Native to Eurasia, but found in Africa, Australia, North America and South America.
• Commonly introduced as an aquarium spp.
• No populations known to exist in CO

• There is only one _______ sp. worldwide.
• Commonly confused with Brazilian waterweed (Egeria densa), another invasive aquatic spp

Hydrilla verticillata (Hydrocharitacea) → hydrilla, waterthyme

CO NOXIOUS WEED LIST A

• Dioecious, perennial, submerged aquatic species.

• Female flowers consist of 3 sepals and 3 petals, white to reddish brown.

• Male flowers are inconspicuous and green.

• Reproduction by tubers, turions, seeds and stem fragments.

• Stems near the top of the water column are highly branched, forming dense mats.

WHO AM I?
• Native to Europe, Asia and Africa.
• Introduced several times as an aquarium plant, as early as 1940.
• Transported around the U.S. on contaminated boats and other recreation equipment

Myriophyllum spicatum (Haloragacea) → Eurasian watermilfoil

CO NOXIOUS WEED LIST B

WHO AM I?
• Native to all of mainland US and many areas of Canada
• Found along roadsides, ditches, waste places, rangeland, and crops
• Not highly competitive in crops but resistance to multiple herbicide MOA’s has been reported

Ambrosia artemisiifolia (Asteraceae)→ common ragweed

WHO AM I?
-Native to Europe
-Grows in disturbed areas such as roadsides, pastures, and lawns.
- Not widely reported across the western US.
Biennial.
- Basal leaves are deeply cut and oblanceolate
– up to 8 in. long.- Stem leaves are smaller, entire.
- Multiple erect stems, hollow, and sparsely hairy.

Scorzonera laciniata (Asteraceae) → cutleaf vipergrass

What weeds (Group 7) are in the Potamogetonaceae Family?

Potamogeton crispus → curlyleaf pondweed
Stuckenia pectinata → sago pondweed

What weeds (Group 7) are in the Hydrocharitaceae Family?

Hydrilla verticillata → hydrilla
CO NOXIOUS WEED LIST A

What weeds (Group 7) are in the Haloragaceae Family?

Myriophyllum spicatum → Eurasian watermilfoil
CO NOXIOUS WEED LIST B

What weeds (Group 7) are in the Asteracea Family?

Ambrosia artemisiifolia → common ragweed
Scorzonera laciniata →  cutleaf vipergrass

Potamogeton -

Potamogeton crispus
curlyleaf pondweed (Potamogetonaceae)

Stuckenia -

Stuckenia pectinata

sago pondweed (Potamogetonaceae)

Hydrilla -

Hydrilla verticillata
hydrilla (Hydrocharitaceae)
CO NOXIOUS WEED LIST A

Myriophyllum -

Myriophyllum spicatum

Eurasian watermilfoil (Haloragaceae)
CO NOXIOUS WEED LIST B

Ambrosia -

Ambrosia artemisiifolia
common ragweed (Asteraceae)

Scorzonera -

Scorzonera laciniata
cutleaf vipergrass (Asteraceae)