CAHNRS > Hortsense > Weeds > Weed Photo Gallery > Weed Photo Gallery (I-Po) Weed Photo Gallery (I-Po) Select a photo below to view associated weed fact sheet. Knapweeds – Pokeweed Weeds: Knapweeds – Centaurea spp. Weeds: Knotweeds (Bohemian, Giant, Japanese, Himalayan) – Polygonum spp. Weeds: Kochia – Kochia scoparia Weeds: Lambsquarters, common – Chenopodium album Weeds: Lesser celandine – Ficaria verna Weeds: Liverworts – Several species Weeds: Mallow, common (Cheeseweed, Buttonweed) – Malva neglecta Weeds: Nightshades – Solanum spp. Weeds: Oxalis (Creeping woodsorrel) – Oxalis corniculata Weeds: Parrotfeather and Eurasian watermilfoil – Myriophyllum spp. Weeds: Pineappleweed – Matricaria discoidea Weeds: Plantain (Broadleaf, Buckhorn) – Plantago spp. Weeds: Poison hemlock – Conium maculatum Weeds: Poison ivy and Poison oak – Toxicodendron spp. (Rhus spp.) Weeds: Pokeweed: Phytolacca americana Weed Gallery A to B C to E F to H I to Po Pr to Sc Sh to Z