dandelion
(Taraxacum officinale G.H. Weber ex Wiggers)

Overview

Appearance

Taraxacum officinale is a perennial that grows best in moist areas in full sun. Its strong taproot is capable of penetrating the soil to a depth of 10-15 ft. (3-4.6 m), but it is most commonly 6-18 in. (15.2-45.7 cm) deep.

Foliage

Leaves are clustered in a rosette at the base of the plant. Leaves vary in length from 2-14 in. (5.1-35.6 cm) and from 0.5-3 in. (1.3-7.6 cm) wide. Margins of the leaves are deeply serrated.

Flowers

Flowering stalks are 6-24 in. (15.2-61 cm) in length and terminate in a compound inflorescence or head that contains 100 to 300 ray flowers and looks like a characteristic puffball. Each ray flower has a strap-shaped yellow petal with five notches at the tip. Taraxacum officinale flowers are not normally pollinated but develop asexually. The seeds are achenes and are about 0.13 in. (0.32 cm) in length with five to eight ribs.

Ecological Threat

Taraxacum officinale can be a major weed problem for turf and ornamental managers. In turf, it forms clumps that cause poor footing for athletic fields and golf courses. When this plant infests turfgrass and ornamental plantings, it forms dense circular mats of leaves that crowd out desirable species and reduce the vigor of those plants that survive.

Selected Images

Maps

Invasive Listing Sources

• City of Ann Arbor Michigan Parks and Recreation
• Jil M. Swearingen, Survey of invasive plants occurring on National Park Service lands, 2000-2007
• John Randall, The Nature Conservancy, Survey of TNC Preserves, 1995.
• National Park Service, Mid-Atlantic Exotic Plant Management Team Invasive Plant List
• Native Plant Society of Oregon, 2008
• Nonnative Invasive Species in Southern Forest and Grassland Ecosystems
• WeedUS - Database of Plants Invading Natural Areas in the United States

References