Native Range

Some of the largest infestations of invasive saltcedars in North America consist of hybrids of Tamarix chinensis and T. ramosissima, while T. parviflora is primarily invasive in California. The classical weed biocontrol agents thus far established on Tamarix in North America primarily attack T. chinensis, T. ramosissima, and to a lesser extent, T. parviflora. Only these species are described in this resource. Tamarix parviflora is native to the eastern Mediterranean Basin. Tamarix chinensis and T. ramosissima are native to Asia.

Appearance

Saltcedars are perennial shrubs or small trees which develop long taproots with extensive creeping lateral roots. Tamarix chinensis and T. ramosissima are similar in appearance, differing only slightly in the shape of their floral parts so that the more common hybrid forms are indistinguishable except by molecular genetic testing. Tamarix ramosissima x chinensis is typically 13–20 ft (4–6 m) tall while T. parviflora is similar in size but tends to be more spreading in its growth form. Saltcedar stems are green and flexible when young, becoming reddish-brown to brown and woody with age. Leaves are tiny, gray-green, and scale-like, and salt-secreting. The foliage is deciduous in cold climates. Saltcedar flowers are produced in tight clusters on branch tips. Flowers of T. ramosissima x chinensis appear after the foliage, and each has five pink petals. Flowers of T. parviflora appear before foliage, and each has only four pink petals. Fruits of all saltcedars are capsules that contain many tiny brown seeds, each topped by a tuft of hairs.

Impact

Saltcedars can reduce stream flow and groundwater by their high evapotranspiration rates. Studies by the US Bureau of Reclamation and others indicate large amounts of water taken up by saltcedars, particularly from the Rio Grande and Colorado River basins. This can be explained by the high leaf or photosynthetic surface area of saltcedar as compared to native plants. These weeds also reduce water quality by increasing the salinity of streams and groundwater. They often increase soil salinity to levels that inhibit germination or growth of other plants. Dense thickets of saltcedar displace native riparian communities, drastically degrading wildlife habit. Saltcedar thickets are highly flammable and have led to larger and more frequent wildfires in desert riparian areas otherwise not prone to burning, which negatively impacts wildlife as well as the ranching sector.

Reference

Bean, D.W. and T.L. Dudley. 2023. Saltcedars (Tamarix spp.): History and Ecology in North America. In: R.L. Winston, Ed. Biological Control of Weeds in North America. North American Invasive Species Management Association, Milwaukee, WI. NAISMA-BCW-2023-33-SALTCEDARS-P. https://bugwoodcloud.org/resource/files/28115.pdf

Resources

• Element Stewardship Abstract - The Nature Conservancy
• Weed Field Guide - USDA Forest Service

Selected Images

Maps

Invasive Listing Sources

• Idaho Noxious Weeds
• Illinois Exotic Weed Act
• Montana Noxious Weeds
• Nebraska Noxious Weeds
• Nevada Noxious Weeds
• New Mexico Noxious Weeds
• North Dakota Noxious Weeds
• Texas Noxious Weeds
• Wyoming Noxious Weeds

References