orchardgrass
(Dactylis glomerata L.)

Overview

Appearance

Dactylis glomerata is a cool-season perennial that grows 1.4-4 ft. (0.43-1.2 m) tall. Under dry conditions it usually develops in clumps.

Foliage

Leaves have a bluish hue and grow up to 0.5 in. (1.3 cm) wide, folded when immature but later flat, with prominent white midrib on the under side.

Flowers

The flowers are yellow and occur in a panicle with spikelets in a compact cluster on one side of the rachilla. Flowers bloom from May to August.

Fruit

Panicle, 2-8 in. (5.1-20.3 cm) long, with spikelets grouped together in dense, one-sided clusters at the end of panicle branches; spikelets contain 2 to 5 florets; lemmas pointed to short-awned.

Ecological Threat

Dactylis glomerata is native to Europe and was first introduced to the United States in the late 1700s. It prefers areas that are well-drained with moderately fertile to rich soils.

Selected Images

Maps

Invasive Listing Sources

• California Invasive Plant Council
• 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.
• Maryland Code and Regulations Noxious Weed & Seed Law
• 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