1.26.97
The Virtual WeedPatch
id.html
seedlingID.html
emergence.html

Weed Identification: Emergence in the Spring*

Emergence Group 0:
Winter Annuals, & Biennials, from the Previous Autumn

~bull thistle (Circium vulgare), a biennial broadleaf
~musk thistle (Carduus nutans), a biennial broadleaf
~downy brome (Bromus tectorum), a winter annual grass
~field pennycress (Thlaspi arvense), a winter annual broadleaf
~horseweed (Conyza canadensis), a winter annual broadleaf
~shepard's purse (Capsella bursa-pastoris), an annual/winter annual broadleaf

[Notice the predominance of biennial thistles, winter annuals, and broadleaf weeds

Group 1: Early Early

~dandelion (Taraxacum officinale), a perennial broadleaf
~foxtail barley (Hordeum jubatum), a perennial grass
~prostrate knotweed (Polygonum aviculare), an annual broadleaf
~wild mustard (Sinapis arvensis), a winter annual/annual broadleaf

[Notice the predominance of perennial and broadleaf weeds]

Group 2: Early

~common lambsquarters (Chenopodium album), an annual broadleaf
~giant ragweed (Ambrosia trifida), an annual broadleaf
~Pennsylvania smartweed (Polygonum pensylvanicum), an annual broadleaf
~quackgrass (Elytrigia repens), a perennial grass
~wild buckwheat (Polygonum convolvulvus), an annual broadleaf

[Notice the predominance of annual broadleaf weeds]

Group 3: Late Early

~common ragweed (Ambrosia artemisiifolia), an annual broadleaf
~multiflora rose (Rosa multiflora), a perennial broadleaf
~smooth brome (Bromus inermis), a perennial grass
~velvetleaf (Abutilon theophrasti), an annual broadleaf
~woolly cupgrass (Eriochloa villosa), an annual grass

---

Group 4: Early Mid

~Canada thistle (Circium arvense), a perennial broadleaf
~erect knotweed (Polygonum erectum), an annual broadleaf
~green foxtail (Setaria viridis), an annual grass

---

Group 5: Mid

~barnyardgrass (Echinochloa crus-galli), an annual grass
~common cocklebur (Xanthium strumarium), an annual broadleaf
~common milkweed (Asclepias syriaca), a perennial broadleaf
~giant foxtail (Setaria faberi), an annual grass
~hemp dogbane (Apocynum cannabinum), a perennial broadleaf
~redroot pigweed (Amaranthus retroflexus), an annual broadleaf

---

Group 6: Late Mid

~common sunflower (Helianthus annuus), an annual broadleaf
~common waterhemp (Amaranthus rudis), an annual broadleaf
~knotroot foxtail (Setaria geniculata), an annual grass
~yellow foxtail (Setaria glauca), an annual grass
~eastern black nightshade (Solanum ptycanthum), an annual broadleaf
~shattercane (Sorghum bicolor), an annual grass
~yellow nutsedge (Cyperus esculentus), a perennial sedge
~wild proso millet (Panicum miliaceum), an annual grass
~wirestem muhly (Muhlenbergia frondosa), a perennial grass

---

Group 7: Late

~large crabgrass (Digitaria sanguinalis), an annual grass
~smooth crabgrass (Digitaria ischaemum), an annual grass
~fall panicum (Panicum dichotomiflorum), an annual grass
~jimsonweed (Datura stramonium), an annual broadleaf
~field bindweed (Convolvulvus arvensis), a perennial broadleaf
~hedge bindweed (Calystegia sepium), a perennial broadleaf

---

*Based on Buhler, Hartzler, Forcella, and Gunsolus, 1996

---

©jdekker-1996