Transcript Malvaceae Genus: Anoda Species: cristata summer annual

Agronomic Weeds – 1
CS 414
Note: weeds occur in a variety of sites,
management schemes, & niches. These
weeds are commonly (not exclusively) found
in agronomic systems.
Amaranthus hybridus
Amaranthaceae
Smooth pigweed
Summer annual, stems densely pubescent
Stems erect & slender
Upper stem is densely hairy
Amaranthus palmeri
Amaranthaceae
Palmer amaranth
Summer annual, alternate, glabrous leaves
Petioles generally longer than blade
White chevron visible on leaves
Becoming a problematic weed as resistance
develops
Amaranthus retroflexus
Amaranthaceae
Redroot pigweed
Summer annual, hairs along leaf
margins, especially on lower leaf
surfaces
Petioles ½”, wavy margins
Shallow taproot, usually reddish in
color
Dense, terminal seed head (not
many seed heads as on Palmer)
Amaranthus spinosus
Amaranthaceae
Spiny amaranth
Summer annual, similar to other pigweeds,
but has spines along stem
Stems below cotyledons are red
Long petioles, no hairs
Pairs of spines at base of most petioles
Ambrosia artemisiifolia
Asteraceae
Common ragweed
Summer annual
Round stem, smooth underside of leaf, sdlgs
look like marigolds, rounded lobes on leaves
Eclipta prostrata
Asteraceae
eclipta
Summer annual
Freely branching, reddish stem, opposite
leaves are hairy and toothed.
Eupatorium capillifolium
Dogfennel
Asteraceae
Perennial
Resembles asparagus-fern, sdlg
leaves highly dissected
Common cocklebur
Xanthium strumarium
Asteraceae
Summer annual
Rough leaf texture, black
spots on stem
Chenopodium album
Amaranthaceae
Common lambsquarters
Summer annual
Purple-tint on stems, mealy
texture on leaves, esp.
on top of plant
Common Name: tropic croton
Family: Euphorbiaceae
Genus: Croton
Species: glandulosus
summer annual
•serrated leaves and white, disc-like
glands that occur above and below the
petiole at the point of attachment to the
stem
•leaves of eclipta are much more linear
in outline and are arranged oppositely
along the stem unlike the alternate
leaves of tropic croton
•stems of tropic croton are hairy
Crotalaria spectabilis
Fabaceae
Showy crotalaria
Summer annual to 6 ft, stems waxy with age, taproot
Upper leaf blade glabrous, lower leaf blade with
appressed hairs
Yellow flowers, seedpod resembles pea pod when
ripe
Cassia obtusifolius
Fabaceae
Sicklepod
Summer annual, rounded cotyledons with
distinctive veining, late emergence (JuneJuly)
Stems erect, glabrous
Leaves opposite with 4 to 6 egg-shaped
leaflets
Seedpod is long & narrow, seed similar in
dimensions to soybean
Sesbania exaltata
Fabaceae
Hemp sesbania
Erect summer annual, becomes woody
with age
Pinnately compound (6-8 leaflets) arranged
oppositely
Legumes are long and narrow, many seeds
Vicia spp.
Fabaceae
Vetches
Herbaceous annuals & perennials, typically
trailing/vining stems
Typical legumes leaves – opposite & pinnately
compound
Fruit is a legume (pod)
Tendrils develop on older leaves
Often used as cover crops or in “natural”
plantings
Abutilon theophrasti
Malvaceae
Velvetleaf (buttonweed)
Summer annual, usually unbranched, covered
with soft hairs
Heart-shaped cotyledons
Taproot
Flowers yellow with 5 petals
Common Name: spurred anoda
Family: Malvaceae
Genus: Anoda
Species: cristata
summer annual
•Seedlings with 1 round
and 1 heart-shaped
cotyledon
•plants with triangularshaped, coarsely-toothed
leaves, pubescent on both
sides
Hibiscus trionum
Malvaceae
Venice mallow
Summer annual, leaves 3 or 5 lobed/deeply cut
Leaves alternate, coarse teeth
Shallow taproot
Flowers open only for a few hours in AM
Yellow petals with purple bases
Seeds pubescent
Sida rhombifolia
Arrowleaf sida
Malvaceae
Summer annual
First true leaf is toothed. Leaf widest at
middle, spines at base of leaves and
stems. Leaf shape is key!
Sida spinosa
prickly sida
Malvaceae
Summer annual
First true leaf not as toothed as S.
rhombifolia. Leaf shape is key! “Spinier”
than S. rhombifolia.
Oenothera laciniata
Onagraceae
Cutleaf eveningprimrose
Biennial or winter annual (rarely summer)
Leaves with deeply toothed margins, red &
yellow flowers
Cotyledons long & thin, plant begins as basal
rosette
Habit can be erect or prostrate