Rosaceae - rose family

Gerald A. Mulligan
Research Scientist and Research Institute Director (retired) and presently Honorary Research Associate, Agriculture and Agri-Food Canada,
Ottawa, Ontario K1A 0C6, Canada

Awarded the George Lawson Medal by the Canadian Botanical Association in 2006.
Awarded the Faculty of Macdonald, McGill University, Most Distinguished Alumni Award on October 18, 2014.
Read his biography "The Real Weed Man" available in print and ebook.

Click here to go to Weed Photos for this family

Potentilla argentea L., silvery cinquefoil, potentille argentée
Perennial, spreading by seeds; apomictic; prostrate to semi-erect; flowers yellow; throughout, but most common in western Quebec, Ontario, and southward; pastures, lawns, roadsides, and waste places; introduced from Europe.

Potentilla norvegica L., rough cinquefoil, potentille de Norvège
Biennial or short-lived perennial, spreading by seeds; stems 6 inches to 2 feet (15 cm. to 6 dm.) high; flowers yellow; throughout; grain fields, pastures, gardens, open woods, and waste places; native of North America.

Potentilla recta L., sulfur cinquefoil, potentille dressée
Perennial, spreading by seeds; flowering stems 6 to 18 inches (15 to 45 cm.) high; petals sulfer yellow; throughout, but most abundant in western Quebec, Ontario, and southward; pastures, hayfields, roadsides, and waste places; introduced from Europe.

Spiraea alba Du Roi, narrow-leaved meadowsweet, spirée blanche
Perennial shrub, up to 4 feet (12 dm.) high; flowers white; in the eastern half of our area; old fields, roadsides, and waste places; native to North America.

Spiraea tomentosa L., hardhack, spirée tomenteuse
A small erect native shrub from 2 to 4 feet (6 to 12 dm.) high. Petals pink to rose; lower surfaces of leaves covered with dense, wooly, often tan-colored, hairs. Moist locations in meadows, old fields, and pastures in the eastern half of our area.

Click on a photo to view an enlarged image.
Weed Name Photo Weed Name Photo
silvery cinquefoil, potentille argentée
(close up)
silvery cinquefoil, potentille argentée
silvery cinquefoil, potentille argentée silvery cinquefoil, potentille argentée
(close up)
silvery cinquefoil, potentille argentée
(seedling)
rough cinquefoil, potentille de Norvège
rough cinquefoil, potentille de Norvège
(seedling)
rough cinquefoil, potentille de Norvège (NC)
rough cinquefoil, potentille de Norvège and sulfur cinquefoil, potentille dressée
(F&M)
sulfur cinquefoil, potentille dressée
sulfur cinquefoil, potentille dressée
(in field)
sulfur cinquefoil, potentille dressée
sulfur cinquefoil, potentille dressée sulfur cinquefoil, potentille dressée
(seedling)
narrow-leaved meadowsweet, spirée blanche hardhack, spirée tomenteuse
(NC)
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