The following is a partial list of weeds that may cause allergic reactions:

Amaranth, pigweedAmaranthus spp.
Annual bluegrassPoa annua L.
BarnyardgrassEchinochloa crus-galli (L.) Beauv.
BermudagrassCynodon dactylon (L.) Pers.
BromeBromus spp.
BuffalograssBuchloe dactyloidos (Nutt.) Engelm.
CanarygrassPhalaris spp.
CheatBromus secalinus L.
CockleburXanthium spp.
DallisgrassPaspalum dilatatum Poir.
DandelionTaraxacum spp.
DockRumax spp.
FoxtailSetaria spp.
CoatgrassAegilops spp.
HempCannabis sativa L.
JohnsongrassSorghum halepense (L.) Pers.
KochiaKochia scoparia (L.) Schrad.
LambsquartersChenopodium spp.
MarsheIderIva xanthifolia Nutt.
NettleUrtica spp.
OrchardgrassDactylis glomerata L.
PlantainPlantago spp.
QuackgrassAgropyron ripens (L.) Beauv.
Red sorrelRumex acetosella L.
RedtopAgrostis albaL.
Russian thistleSalsoli kali L.
RyegrassLolium multiflorum Lam.
SagebrushArtemisia spp.
SaltbrushAtriplex spp.
SaltgrassDistichlis spicata (L.) Greene
SudangrassSorghum sudanense (Piper) Stapf
Velvetgrass, commonHolcus lanatus L.
WormwoodArtemisia spp.