Weeds: Knapweeds – Centaurea spp. Categories: Broadleaf I-Po Weeds Last review date: 2026-06-05 04:59 Family: Asteraceae (Compositae) Cycle: Biennial/perennial Plant type: Broadleaf Spotted knapweed flowerheads Photo by: B.F. Roche Biology Knapweeds are short-lived perennials with stout taproots. They can have one or more stems, reaching one to three feet in height. Depending on species, leaves […]
Weeds: Knotweeds (Bohemian, Giant, Japanese, Himalayan) – Polygonum spp. Categories: Broadleaf I-Po Weeds Last review date: 2026-06-05 05:00 Family: Polygonaceae Cycle: Perennial Plant type: Broadleaf Japanese knotweed leaves Photo by: J.A. Kropf Biology The giant knotweeds are aggressive plants that spread via long rhizomes and also by seeds. They are deciduous plants, with the woody, […]
Weeds: Kochia – Kochia scoparia Categories: Broadleaf I-Po Weeds Last review date: 2026-06-05 05:01 Family: Chenopodiaceae Cycle: Annual Plant type: Broadleaf Kochia showing fall color Photo by: J.A. Kropf Biology Kochia has a single stem reaching one to six feet high. The main stem is branched above, but typically unbranched at the base. Leaves are […]
Weeds: Lambsquarters, common – Chenopodium album Categories: Broadleaf I-Po Weeds Last review date: 2026-06-05 05:01 Family: Chenopodiaceae Cycle: Annual Plant type: Broadleaf Common lambsquarters Photo by: T.W. Miller Biology Common lambsquarters is typically an upright, branching plant growing one to four feet high from a taproot. The stems are ridged or angular in cross-section and […]
Weeds: Lesser celandine – Ficaria verna Categories: Broadleaf I-Po Weeds Last review date: 2026-06-05 05:03 Family: Ranunculaceae Cycle: Perennial Plant type: Broadleaf Lesser celandine close-up Photo by: S. Campbell Biology Lesser celandine is a noxious weed. It is highly variable and has club-shaped, tuberous roots. The weed grows as a mounded rosette with basal and […]
Weeds: Liverworts – Several species Categories: Bryophyte (mosses & liverworts) I-Po Weeds Last review date: 2026-06-05 08:30 Family: Various Cycle: Plant type: Bryophyte (mosses & liverworts) Liverworts in pot Photo by: J. Altland Biology Liverworts are low-growing, non-flowering relatives of mosses. They are typically small plants that grow prostrate on the ground. Lacking true roots, […]
Weeds: Mallow, common (Cheeseweed, Buttonweed) – Malva neglecta Categories: Broadleaf I-Po Weeds Last review date: 2026-06-05 05:05 Family: Malvaceae Cycle: Various Plant type: Broadleaf Mallow flower Photo by: T.W. Miller Biology Common mallow can be an annual, winter annual, or biennial plant. The plants are spreading from a deep root, with branches reaching from a […]
Weeds: Nightshades – Solanum spp. Categories: Broadleaf I-Po Weeds Last review date: 2026-06-05 05:06 Family: Solanaceae Cycle: Annual/Perennial Plant type: Broadleaf Cutleaf nightshade with fruit Photo by: D.G. Swan Biology Nightshades are annual or perennial taprooted plants that spread by seeds. They usually have spreading, branched stems to three feet tall. The alternate leaves are […]
Weeds: Oxalis (Creeping woodsorrel) – Oxalis corniculata Categories: Broadleaf I-Po Weeds Last review date: 2026-06-05 05:07 Family: Oxalidaceae Cycle: Perennial Plant type: Broadleaf Woodsorrel leaves and flower Photo by: J.A. Kropf Biology Creeping woodsorrel is a prostrate plant, initially growing from a slender taproot. Branches lie flat on the ground, rooting at the nodes to […]
Weeds: Parrotfeather and Eurasian watermilfoil – Myriophyllum spp. Categories: Broadleaf aquatic I-Po Weeds Last review date: 2026-06-05 05:09 Family: Haloragaceae Cycle: Perennial Plant type: Broadleaf aquatic Partotfeather fronds Photo by: T.W. Miller Biology These rhizomatous perennials exhibit an annual pattern of growth. In the spring, shoots begin to grow rapidly from overwintering rhizomes as water […]
