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Annual Broadleaf
Herbaceous Plants
· 25 ·
Annual Herbaceous Broadleaf Plants
n
Annual ragweed
Ambrosia artemisiifolia
Asteraceae
B
A
D
C
E
F
A. Plant on a bog. B. Cluster of male flowers. C. Female flowers in leaf axil.
D. Compound leaf. E. Stem. F. Base of plant and root system.
Both native and introduced in U.S. states; native for Canada. Annual
plant. Blooms in summer-fall.
Botanical description: leaves are simple, opposite (usually towards the
base) or alternate, irregularly toothed and deeply lobed. Leaves can also be
pinnately compound. Older leaves tend to be hairless; younger leaves usually
have hairy undersides. Upright, hairy, branching stems are 8 to 40” (20 to
100 cm) tall. Male flowers (parts indistinguishable) are yellow and grouped in
clusters (racemes) at the top of the stem and the tips of the branches; female
flowers (parts indistinguishable) are greenish, inconspicuous and located in
the leaf axils. Distinctive features: seed have extended longevity in the soil.
Note: ragweed pollen is a significant allergen in late summer.
Favorable growing conditions: grows well in moist and clay-type soils
where the pH is between 6 and 7. It grows well in locations with direct sunlight.
Prevention and suppression: hand-weed plants prior to seed formation.
Clean bog edges. Maintain a healthy canopy of cranberry vines. Keep soil pH
low.
Annual Broadleaf Herbaceous Plants
· 27 ·
H
I
G
J
K
L
G. Mature plant. H. Young plant. I. Seedling with 4 leaves, opposite.
J. Seedling with 2 leaves, with first leaves rounded. K. Plants, top view. L. Infestation.
· 28 ·
Annual Broadleaf Herbaceous Plants

Nodding beggartick
Bidens cernua
Asteraceae
A
D
B
C
E
A. Plants in the field. B. Hairs on stem and base of leaves. C. Leaf.
D. Flowers. E. Opposite leaves.
Native to all regions; not reported in NL. Annual plant. Blooms in
summer.
Botanical description: opposite, simple, long leaves (1.5 to 7.8”; 4 to
20 cm) have toothed margins; leaves are sessile (no petiole). Upright stems
are 12 to 30” (30 to 80 cm) tall, often reddish, and covered with long rigid
hairs. Yellow flowers (parts indistinguishable) with a brownish yellow center, are 1.5 to 2” (4 to 5 cm) in diameter, usually with 8 petals (sometimes
without petals); green narrow leaf-like bracts are beneath flowers. First leaves
(cotyledons) are long. Distinctive features: at maturity, flower clusters are
droopy or nodding.
Favorable growing conditions: well-adapted to moist environments.
They are often found in ditches along fields. This plant will colonize different
soil types including organic soil.
Prevention and suppression: prevent seed formation and hand-weed
young plants. Keep bog edges and irrigation canals clean.
Annual Broadleaf Herbaceous Plants
· 29 ·
F
G
H
I
J
F-G. Seedlings. H. Older seedling with root. I. Plants at edge of field. J. Infestation.
· 30 ·
Annual Broadleaf Herbaceous Plants

Devil’s beggartick
Bidens frondosa
Asteraceae
B
C
A
D
E
A. Plant at the onset of flowering. B. Flower. C. Leaf. D. Young plant.
E. Whole plant with roots.
Native to all U.S. states; introduced to all Canadian provinces. Annual
plant. Blooms in summer-fall.
Botanical description: opposite, pinnately compound leaves, with 3 to
5 toothed, lanced-shaped leaflets. Erect, smooth stems are 24 to 40”
(60 to 100 cm) tall. Flowers (parts indistinguishable) are surrounded by
5 to 10 green bracts that are longer than the petals. Petals are yellow-orange.
Seed are flat with 2 barbed spines (hooks).
Favorable growing conditions: well adapted to moist environments and
tolerates dry areas as well. It will easily colonize different types of soil including organic soils.
Prevention and suppression: hand-weed before seed formation and
clear bog edges and irrigation ditches.
Annual Broadleaf Herbaceous Plants
· 31 ·
nn
American burnweed
Other common names: fireweed, pilewort — Erechtites hieraciifolius
(=E. hieraciifolia) — Asteraceae
B
A
C
D
E
F
A. Mature plant. B. Flower buds. C. Unopened buds and open flower with fine hairs.
D. Plant in the field. E-F. Underside and top of leaf.
Native to all growing regions; not reported in BC, NL. Annual plant.
Blooms in summer-fall.
Botanical description: oval, elongated, alternate, simple leaves with toothed margins and undersides that are gray/green. Upright stems have few
branches, 8 to 32” (20 to 80 cm) tall, and are usually covered with hairs.
Flowers (parts indistinguishable) are whitish or greenish, clustered as cylindrical buds at the top of the stem and in leaf axils. Fruit are brown seed with
tufts of bright white hairs, produced in large numbers (many thousands), and
easily dispersed by the wind. Cotyledons are oblong.
Favorable growing conditions: grows well in dry sandy soils. It grows in
disturbed and open, sunny locations.
Prevention and suppression: prevent seed formation and hand-weed
young plants. Keep edges and ditches clean. Maintain a healthy canopy of
cranberry vines.
· 32 ·
Annual Broadleaf Herbaceous Plants
G
H
I
J
K
L
G. Young plant in the bog. H-I-J. Young plants, seedlings. K. Infestation close-up.
L. Infestation (note the presence of other woody plants).
Annual Broadleaf Herbaceous Plants
· 33 ·
n
Marsh cudweed
Other common names: Low cudweed, catfoot, everlasting —
Gnaphalium uliginosum — Asteraceae
B
A
C
D
E
F
A. Plant on a bog. B. Flowers. C. Stem and petiole covered in hairs. D. Young plant
on a bog. E. Seedling. F. Infestation.
Introduced species to all regions. Annual or short-lived perennial
plant. Blooms in summer.
Botanical description: branches come out of the plant base, looking like
a basket. Alternate leaves with entire margins are simple, without petioles,
small, elongated (a bit enlarged on top), and densely covered with white hairs.
Stems are generally less than 8” (20 cm) tall. Flowers (parts indistinguishable)
are small, whitish or brownish and grouped in clusters at the tops of stems
and in the leaf axils. Seedlings are rosettes; stems do not elongate in the early
stages of growth. This plant propagates exclusively by seed.
Favorable growing conditions: grows well in dry areas but can be found in
moist locations. Often present in disturbed locations.
Prevention and suppression: hand-weed plants at the start of summer. Maintain a healthy cranberry canopy.
· 34 ·
Annual Broadleaf Herbaceous Plants
n
Jewelweed
Impatiens capensis
Balsaminaceae
B
A
C
D
E
A. Plant in field. B. Flower. C. Seed pod. D. Young plant on a bog. E. Stem crosssection and swollen node.
Native to all growing regions. Annual plant. Blooms in summer.
Botanical description: plant is entirely hairless. Leaves are alternate,
simple, elliptical to oval, with coarsely toothed margins. Translucent stems
are hollow, 20 to 40” (50 to 100 cm) tall. Orange flowers (irregular) are extensively speckled with red-brown, have a short inward-curved spur at the back,
and dangle from a long stalk. Fruit is a plump, green pod containing 4 to
6 seeds. Seedlings appear only in the spring; cotyledons are approximately
circular (orbicular), indented on their ends. Distinctive features: at maturity,
fruit pods rupture at the slightest touch.
Favorable growing conditions: grows well in moist, rich soil and shade.
Prevention and suppression: hand-weed plants prior to seed formation.
Annual Broadleaf Herbaceous Plants
· 35 ·
F
G
H
I
F. Stem, note red-orange tint. G. Plants on a bog. H. Seedling at the 2-leaf stage.
I. Colony.
· 36 ·
Annual Broadleaf Herbaceous Plants
n
Corn spurry
Spergula arvensis
Caryophyllaceae
A
C
B
D
A. Plant on the bog. B. Mature plant. C. Open seed pod . D. Seedling with linear first
leaves.
Introduced to all regions. Annual plant. Blooms in summer and fall.
Botanical description: usually hairless but may be slightly hairy. Leaves
are whorled in groups of 6 or more, simple, entire margins, mostly hairless,
very narrow, up to 1.4” (3.5 cm) long. Upright branching stems, or occasionally without branches, are 4 to 16” (10 to 40 cm) tall. Small, white flowers
(5 petals) and are at the ends of stems and in leaf axils. Fruit have 5 valves that
contain a large number of very small seeds. Cotyledons are linear. Distinctive
features: Corn spurry produces many seeds that will germinate the following
spring; the new plants often produce a dense carpet of weeds.
Favorable growing conditions: grows well in sandy, acidic soils, and
sunny locations.
Prevention and suppression: hand-weed bogs prior to seed formation.
Maintain a healthy cranberry canopy. Use clean cuttings at planting time.
Annual Broadleaf Herbaceous Plants
· 37 ·
E
F
G
H
E. Young plant on a bog. F. Whole young plant. G. Plants on a bog. H. Flowering
colony around an irrigation head.
· 38 ·
Annual Broadleaf Herbaceous Plants

Lambsquarters
Other common names: goosefoot — Chenopodium album
Chenopodiaceae
B
A
C
D
A. Plant in field. B. Flowering cluster. C. Leaf. D. Young plants.
Both native and introduced for US and Canada. Annual plant. Blooms
in summer.
Botanical description: hairless plant. Leaves are alternate, simple, toothed,
often rhombic to egg-shaped to lanceolate; new leaves often have a whitish coating. Upright stems are 8 to 40” (20 to 100 cm) tall and often with maroon stripes.
Numerous small, green, sessile flowers (parts indistinguishable) are produced in
spikes grouped into a panicle at the end of the stems and in the leaf axils. Seed are
very small, smooth, and black. Seed are produced in large quantities (many tens of
thousands). Cotyledons are elongated.
Favorable growing conditions: this plant easily adapts to all types of soil
at most pH levels, growing best in high-nutrient soils (or compost) that are well
drained.
Prevention and suppression: prevent seed formation and hand-weed young
plants. Maintain a healthy canopy of cranberry vines.
Annual Broadleaf Herbaceous Plants
· 39 ·

Oakleaf goosefoot
Chenopodium glaucum
Chenopodiaceae
A
B
C
E
F
D
A. Plant in field. B. Mature plant. C. Flowers. D. Leaf. E. Seedling. F. Plant colony.
Introduced species for all northeastern U.S. states, MI, WI; native
in QC, ATL; not reported in BC, OR, WA. Annual plant. Blooms in
summer.
Botanical description: leaves are simple, alternate, elongated, 1 to 2”
(1.5 to 5 cm) long, oval, with bluntly toothed margins (like an oak leaf), dark
green often tinted with red. Smooth stems are sprawling and about 20”
(50 cm) tall. Flowers (parts indistinguishable) are very small, greenish, grouped in compact clusters in the leaf axils or terminal cluster. Cotyledons are
elongated.
Favorable growing conditions: adapted to different types of soil, including organic soils. It also tolerates poorly drained soils.
Prevention and suppression: prevent seed formation and hand-weed
young plants. Maintain a healthy canopy of cranberry vines.
· 40 ·
Annual Broadleaf Herbaceous Plants

Orangegrass
Other common names: pineweed, orangegrass St. Johnswort —
Hypericum gentianoides — Clusiaceae
A
B
C
E
F
D
A. Emerging plants. B. Flowering plants. C. Whole plant. D. Stems.
E. Flower. F. Fruit.
Native species in MA, ME, NJ, NS, NY, MI, RI, WI; not reported in BC,
NB, NL, OR, PEI, QC, WA. Annual plant. Blooms in summer-early fall.
Botanical description: leaves are simple, opposite, scale-like, pressed to the
stem and up to 5 mm long. Round or mostly round stems can be 4 to 20” (10 to
50 cm) tall, but are usually in the shorter range in cranberry beds. Small, yellow,
nearly stemless flowers (5 petals) are on wiry, ascending branches. Flowers are
3 to 6 mm wide. Fruit are small, smooth, lance-shaped red capsules and are much
longer than the sepals.
Favorable growing conditions: sandy, rocky, sunny areas.
Prevention and suppression: common in new plantings and can be overlooked
due to similarity in appearance to cranberry. It can be easily hand-pulled but may
not be practical if infestation is widespread.
Similar species: Nits-and-Lice (H. drummondii) has fewer branches, a broad oval
fruit capsule, and longer leaves, 0.5 to 1” (12 to 25 mm) in length. See other Hypericum spp. , p.xxx-xx.
Annual Broadleaf Herbaceous Plants
· 41 ·

Garden vetch
Other common names: common vetch — Vicia sativa ssp. nigra
(= V. angustifolia) — Fabaceae
A
B
C
E
F
D
A. Whole plant. B. Stem. C. Leaf. D. Tendril on end of stem. E. Flower. F. Fruit.
Introduced species in all regions. Annual plant or vine. Blooms in
spring-fall.
Botanical description: leaves are alternate, pinnately compound with a
terminal leaflet modified into a twining tendril. Leaflets have entire margins,
linear to narrowly elliptical 0.6 to 1.2” (1.5 to 3 cm) long with 3 to 5 pairs per
leaf. Plant height is 6 to 40” (15 to 100 cm). Flowers (irregular) are typically
arranged in a spiral around an axis, blue to violet, occasionally white, 0.75
to 1” (1.8 to 2.5 cm) long. Fruit are pods that are 1.5” (4 cm) long and light
brown at maturity.
Favorable growing conditions: found in many types of environments
including sandy and gravelly soils.
Prevention and suppression: a healthy cranberry canopy will suppress
the growth of vetches.
Similar species: winter vetch (V. villosa; not described) is a summer or winter annual or biennial, has hairy stems and leaves are narrowly oblong. It
has 5 to 10 pairs per leaf. Flowers are reddish-purple and pods are shorter
(2 to 3 cm).
· 42 ·
Annual Broadleaf Herbaceous Plants
n
Green carpetweed
Other common names: Indian chickweed, whorled chickweed,
devils-grip — Mollugo verticillata — Molluginaceae
A
B
C
D
E
A. Sprawling plant on a bog. B. Whorl of leaves . C. Flower. D. Young plant. E. Fruit.
Native to U.S. states; introduced species to Canadian provinces; not
reported in NL and PEI. Annual plant. Blooms in summer.
Botanical description: small, highly branched, prostrate, spreading plant
that forms circular mats. Leaves have entire margins, and are simple and
sessile. They are grouped in a whorl of 4 to 6 leaves at each node of the
stem, rounded above and narrow to the base (like a spatula) or widest above
the middle and tapering to the base. Stems are round and hairless. Flowers
(5 petals) are small, whitish, on short pedicels. The fruit, an egg-shaped pod
with three valves, contains many seeds.
Favorable growing conditions: grows in dry locations with sand and gravel, but can also tolerate extended periods of moisture.
Prevention and suppression: hand-weed plants before seed formation.
Maintain a healthy cranberry canopy. Use clean cuttings.
Similar species: chickweeds (Stellaria; see p.xx) and speedwells (Veronica;
not described) have alternate or opposite leaves and do not have forked branching. Bedstraws (Galium; see p.xx) have whorls of leaves but have square
stems.
Annual Broadleaf Herbaceous Plants
· 43 ·
F
G
H
F. Base of plant, with swollen nodes. G. Close-up of plants on a bog.
H. Colony on a bog .
· 44 ·
Annual Broadleaf Herbaceous Plants
nn
Marshpepper smartweed
Polygonum hydropiper
Polygonaceae
A
B
C
D
E
A. Plant on a bog. B. Flowers. C. Slender, arching flower spike D. Leaves. E. Ochrea at
base of petiole.
Introduced to all regions. Annual plant. Blooms in summer.
Botanical description: elongated, simple, alternate leaves with entire
or wavy margins; leaves, 3/16 to 1” (5 to 25 mm) wide, are often mottled.
Upright branching stems are 8 to 24” (20 to 60 cm) tall. A sheath (ochrea)
encircles the stem at the base of each node. Flowers (5 petals spotted with
numerous small glands) are small and reddish or whitish, are grouped in long
spikes that are slender and arched and located at the end of the stem and in
leaf axils. Cotyledons are oblong. Distinctive features: known for the pepper
flavor of its leaves.
Favorable growing conditions: grows well in moist soils and sunny locations.
Prevention and suppression: prevent seed formation and hand-weed
young plants. Clean bog edges and irrigation ditches.
Annual Broadleaf Herbaceous Plants
· 45 ·
F
G
H
F. Seedling. G. Group of seedlings. H. Infestation.
Similar species: swamp smartweed (P. hydropiperoides; not described) is a
perennial plant (has stolons) and its petals are not spotted with glands. Japanese
knotweed (P. cuspidatum = Fallopia japonica; not described) is one of the most invasive plants in the world; it can grow up to 8 ft (2.4 m) tall. Its leaf blades are
0.75 to 4” (2 to 10 cm) wide and without hairs on the underside; its flowers are
usually white. Its leaf shape is very different from other knotweeds; the leaf base
ends abruptly in a more or less straight line as though cut off. Water knotweed
(P. amphibium; not described) can grow under water, floating or emergent; it has a
dense cluster of many 5-lobed pink flowers
· 46 ·
Annual Broadleaf Herbaceous Plants

Curlytop knotweed
Other common names: Pale smartweed — Polygonum lapathifolium
Polygonaceae
A
B
C
D
A. Plant on a bog. B. Leaf. C. Long slender spike of flowers. D. Base of the petiole
with ochrea.
Native to U.S. states; introduced to Canadian provinces. Annual
plant. Blooms in summer.
Botanical description: elongated, simple, alternate leaves with entire
margins; leaf is often marked with dark spot on its center. Upright branching
stems have swollen nodes or joints, are 24 to 48” (60 to 120 cm) tall, often
reddish and marked with red flecks. A membranous sheath (ochrea) encircles
the stem at each petiole. Flowers (5 petals) are small, rose-like, grouped on
long spikes that are slim and arched at the top of the stem and branches.
Distinctive features: characterized by its distinctive and colorful ochreas.
Favorable growing conditions: grows well in moist soils.
Prevention and suppression: hand-weed plants prior to seed formation.
Clean the edges of bogs and irrigation ditches.
Similar species: see marshpepper smartweed, p.xx and spotted ladysthumb p.xx.
Annual Broadleaf Herbaceous Plants
· 47 ·
n
Spotted ladysthumb
Polygonum persicaria (= Persicaria maculosa)
Polygonaceae
A
B
C
D
A. Plants on a bog. B. Dense spike with rose-colored flowers. C. Leaf.
D. Ochrea at base of the petiole.
Introduced species to all regions. Annual/Perennial plant. Blooms in
summer.
Botanical description: elongated, simple, alternate leaves with entire
margins; leaves are 0.4 to 7” (1 to 18 cm) long and often marked with a dark
center spot. Upright branching stems are 8 to 32” (20 to 80 cm) tall and are
swollen at the nodes. A sheath (ochrea), the fringe topped with hairs, encircles
the stem at the base of the petiole. Small rose flowers (5 petals), grouped in
dense spikes at the top of the stem and in leaf axils.
Favorable growing conditions: well adapted to a variety of soil types, but
also grows in well-drained soils.
Prevention and suppression: hand-weed plants prior to seed formation.
Similar species: Pennsylvania smartweed (P. pensylvanicum; not described)
is an annual plant. Leaves do not have a dark center spot and can be longer
1.5 to 9” (4 to 23 cm). Flower stalks usually have red glands that are on short
stalks (stipes); the inflorescences of spotted ladysthumb are usually smooth
or barely hairy. See marshpepper smartweed, p.xx..
· 48 ·
Annual Broadleaf Herbaceous Plants
nn
Arrowleaf tearthumb
Polygonum sagittatum
Polygonaceae
B
A
D
C
E
F
A. Plant on a bog. B-C. Flowers: reddish and whitish. D. Arrow-shaped leaf. E. Foursided stem with downward-pointing spines. F. Ochrea at base of the petiole.
Native to all regions; not reported in BC and WA. Annual or Perennial plant or vine. Blooms in summer
Botanical description: often laying on top of or entwined with other
plants. Elongated, simple, alternate leaves with entire margins have two
arrow-like lobes near the base, which are characteristic of the plant. Slender
and weak stems are 16 to 32” (40 to 80 cm) long. A sheath (ochrea) at the
base of each petiole encircles the stem at each node. Flowers (parts indistinguishable) are small, reddish and whitish, grouped in small, slender spikes at
the end of the stem and in leaf axils. Distinctive features: square stem has
downward-facing spines.
Favorable growing conditions: grows well in very moist soils with ample
sun and some shade.
Prevention and suppression: hand-weed bogs prior to seed formation.
Clean bog edges and irrigation ditches.
Similar species: see marshpepper smartweed, p.xx and spotted ladysthumb p.xx.
Annual Broadleaf Herbaceous Plants
· 49 ·
H
G
I
J
K
G-H. Seedlings. I. Base of plant with roots. J. Colony of non-flowering plants.
K. Infestation of flowering plants.
· 50 ·
Annual Broadleaf Herbaceous Plants
n
Green smartweed
Polygonum scabrum
Polygonaceae
A
B
C
D
E
A. Plants in field. B. Dense spike of white/greenish flowers. C-D. top side (c) and
under side (d) of leaf. E. Ochrea at base of petiole.
Native to US. Introduced to Canada. Annual plant. Blooms in summer.
Botanical description: elongated, alternate, simple leaves with entire
margins, often with a dark spot in the center; young leaves have soft hairs.
Upright branching stems are 8 to 32” (20 to 80 cm) tall. A sheath (ochrea)
at the base of the petiole encircles the stem at each node. Small flowers
(5 petals) are greenish/whitish, grouped in dense spikes at the top of the
stem and leaf axils. Note: considered synonymous for P. lapathifolim according
to USDA Plant Database.
Favorable growing conditions: adapted to different types of soil, but
grows well in well-drained soils.
Prevention and suppression: hand-weed plants before seed formation.
Similar species: see marshpepper smartweed, p.xx and spotted ladysthumb p.xx.
Annual Broadleaf Herbaceous Plants
· 51 ·