Weeds: Prickly lettuce (China lettuce) – Lactuca serriola Categories: Broadleaf Pr-Sc Weeds Last review date: 2026-06-07 04:41 Scientific name: Lactuca serriola Family: Asteraceae (Compositae) Cycle: Annual/Biennial Plant type: Broadleaf Prickly lettuce leaves Photo by: R. Parker Biology Prickly lettuce grows from one to five feet tall from a large taproot. The sap is milky. Seedling […]
Weeds: Prostrate knotweed – Polygonum aviculare Categories: Broadleaf Pr-Sc Weeds Last review date: 2026-06-07 06:56 Scientific name: Polygonum aviculare Family: Polygonaceae Cycle: Annual Plant type: Broadleaf Prostrate knotweed leaves Photo by: R. Parker Biology Prostrate knotweed is a low-growing plant with wiry stems and a thin taproot. Plants branch extensively at the base, with branches […]
Weeds: Puncturevine (Tackweed, Goathead) – Tribulus terrestris Categories: Broadleaf Pr-Sc Weeds Last review date: 2026-06-07 09:09 Scientific name: Tribulus terrestris Family: Zygophyllaceae Cycle: Annual Plant type: Broadleaf Puncturevine Photo by: R. Parker Biology Puncturevine is a prostrate plant growing from a taproot. Above ground, the branching, trailing stems grow one to six feet and are […]
Weeds: Purple deadnettle (Red deadnettle) – Lamium purpureum Categories: Broadleaf Pr-Sc Weeds Last review date: 2026-06-07 06:14 Scientific name: Lamium purpureum Family: Lamiaceae (Labiatae) Cycle: Annual Plant type: Broadleaf Purple deadnettle flowers Photo by: C.R. Foss Biology Purple deadnettle has the square stems and opposite leaves characteristic of most plants in the mint family. Plants […]
Weeds: Purple loosestrife (Purple lythrum) – Lythrum salicaria Categories: Broadleaf Pr-Sc Weeds Last review date: 2026-06-07 06:20 Scientific name: Lythrum salicaria Family: Lythraceae Cycle: Perennial Plant type: Broadleaf Purple loosestrife in bloom Photo by: N.R. Ness Biology Purple loosestrife is an erect plant growing six to eight feet tall from a woody, rhizomatous root system. […]
Weeds: Purslane, common – Portulaca oleracea Categories: Broadleaf Pr-Sc Weeds Last review date: 2026-06-07 07:05 Scientific name: Portulaca oleracea Family: Portulacaceae Cycle: Annual Plant type: Broadleaf Common purslane succulent leaves and flower Photo by: D.G. Swan Biology Common purslane reproduces by seeds, but it can also root from the stems or stem fragments which contact […]
Weeds: Quackgrass – Elymus repens (Elytrigia repens, Agropyron repens) Categories: Grasses Pr-Sc Weeds Last review date: 2026-06-07 10:15 Scientific name: Elymus repens (Elytrigia repens, Agropyron repens) Family: Poaceae (Graminae) Cycle: Perennial Plant type: Grass Quackgrass Photo by: D.G. Swan Biology Quackgrass is a perennial grass which spreads by both seeds and rhizomes, forming dense clumps […]
Weeds: Red sorrel (Sheep sorrel) – Rumex acetosella Categories: Broadleaf Pr-Sc Weeds Last review date: 2026-06-07 07:13 Scientific name: Rumex acetosella Family: Polygonaceae Cycle: Perennial Plant type: Broadleaf Red sorrel leaves Photo by: T.W. Miller Biology Red sorrel has a creeping root system and spreads aggressively by underground roots and rhizomes. The upright, somewhat woody […]
Weeds: Redroot pigweed (Rough pigweed) – Amaranthus retroflexus Categories: Broadleaf Pr-Sc Weeds Last review date: 2026-06-07 02:34 Scientific name: Amaranthus retroflexus Family: Amaranthaceae Cycle: Annual Plant type: Broadleaf Redroot pigweed Photo by: D.G. Swan Biology Redroot pigweed is a course, erect plant, growing two to three feet tall. The lower stems and branches and the […]
Weeds: Redstem filaree (Stork’s bill, Crane’s bill) – Erodium cicutarium Categories: Broadleaf Pr-Sc Weeds Last review date: 2026-06-07 04:15 Scientific name: Erodium cicutarium Family: Geraniaceae Cycle: Annual Plant type: Broadleaf Redstem filaree fruit and flowers Photo by: R. Parker Biology Redstem filaree is typically a winter annual (sometimes a biennial) growing from a rosette. The […]
Weeds: Reed canarygrass – Phalaris arundinacea Categories: Grasses Pr-Sc Weeds Last review date: 2026-06-07 10:15 Scientific name: Phalaris arundinacea Family: Poaceae (Graminae) Cycle: Perennial Plant type: Grass Reed canarygrass emerging in spring Photo by: B.M. Johnson Biology An aggressive plant, reed canarygrass grows from a large root system. It spreads rapidly by seeds and rhizomes […]
Weeds: Russian thistle (Tumbleweed) – Salsola tragus (S. iberica, S. kali) Categories: Broadleaf Pr-Sc Weeds Last review date: 2026-06-07 07:47 Scientific name: Salsola tragus (S. iberica, S. kali) Family: Chenopodiaceae Cycle: Annual Plant type: Broadleaf Russian thistle seedling Photo by: J.A. Kropf Biology Russian thistle is a densely branched plant from an extensive root system. […]
Weeds: Ryegrass, annual (Italian ryegrass) – Lolium perenne ssp. multiflorum Categories: Grasses Pr-Sc Weeds Last review date: 2026-06-07 10:17 Scientific name: Lolium perenne ssp. multiflorum Family: Poaceae (Graminae) Cycle: Annual Plant type: Grass Ryegrass spikelets Photo by: T.W. Miller Biology Annual ryegrass is upright, growing in clumps often reaching four feet tall. The flat leaf […]
Weeds: Salsify (Goatsbeard) – Tragopogon spp. Categories: Broadleaf Pr-Sc Weeds Last review date: 2026-06-07 09:05 Scientific name: Tragopogon spp. Family: Asteraceae (Compositae) Cycle: Biennial Plant type: Broadleaf Salsify flower Photo by: R. Parker Biology Salsify plants are somewhat grass-like in appearance, with slender, pointed leaves which may be as long as twelve inches. The juice […]
Weeds: Scotch broom – Cytisus scoparius Categories: Broadleaf Pr-Sc Weeds Last review date: 2026-06-07 04:09 Scientific name: Cytisus scoparius Family: Fabaceae (Leguminosae) Cycle: Perennial Plant type: Broadleaf Scotch broom flowers Photo by: T.W. Miller Biology Scotch broom is an aggressive, woody shrub reaching up to ten feet in height. The slim, angular, green branches are […]
