Spanish broom
Spartium junceum L.

Overview

Appearance

Spartium junceum is a perennial shrub, that can grow up to 9.8 ft. (3 m) high. It has thick waxy stems.

Foliage

Spanish broom has long, slender, leafless or few-leaved, green branches. The shrub is virgately branched and contains no spines, unlike gorse (Ulex europaeus). The alternate leaves are simple, entire and more or less strigose, having short petioles. The narrower leaves are 0.4-1.2 in. (1-3 cm) long.

Flowers

The fragrant yellow flowers are borne in loose terminal racemes, unlike those of Cytisus scoparius which are usually solitary in the axils. Individual flowers are 0.8-1 in. (2-2.5 cm) long.

Fruit

Seeds can remain viable in soil for more than 80 years.

Ecological Threat

S. junceum is adapted to dryer sites where its lack of leaves and thick waxy stems resist dessication. Like other broom species, it offers strong competition to other plants and contributes to increased maintenance costs on lands where it becomes established. Dry summer plants create a severe fire hazard.

General Description:The following description of Spartium junceum is adapted from Munz and Keck (1973).

Spartium junceum is a perennial shrub, up to 3 m high, with long, slender, leafless or few-leaved, green, rushlike branchlets. The shrub is virgately branched and contains no spines, unlike gorse (Ulex europaeus). The alternate leaves are simple, entire and more or less strigose, having short petioles. The oblance-oblong or narrower leaves are 1-3 cm long.

The fragrant yellow flowers are borne in loose terminal racemes, unlike those of Cytisus scoparius which are usually solitary in the axils. Individual flowers are 2-2.5 cm long. The banner and keel are longer than the wings, and the keel is pubescent along its lower edge. The calyx is split above, hence one-lipped, with 5 minute teeth. This may be contrasted with the two-lipped calyx of Cytisus monspessulanus. The stamens are monadelphous (united by their filaments forming a tube around the gynoecium).

Resources

• Element Stewardship Abstract - The Nature Conservancy

Selected Images

Maps

Invasive Listing Sources

• California Invasive Plant Council
• California Noxious Weeds
• 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.
• Native Plant Society of Oregon, 2008
• New Invaders of the Northwest
• Oregon Noxious Weeds
• Pacific Northwest Exotic Pest Plant Council, 1998
• Reichard, Sarah. 1994.  Assessing the potential of invasiveness in woody plants introduced in North America. University of Washington Ph.D. dissertation.
• Washington Noxious Weeds
• WeedUS - Database of Plants Invading Natural Areas in the United States

References