guayule Asteraceae Parthenium
argentatum A. Gray symbol: PAAR5
Leaf: Alternate, simple, evergreen, lanceolate to ovate, 1 to 3 inches long, entire or with a few scatterd teeth or shallow lobes, gray-green with abundant silvery hairs above and below.
Flower: Small, pale yellow to white flower which occurs in dense flat topped, many branched, terminal clusters, appearing nearly year round whenever just a small amount of rain occurs.
Fruit: A small achene in tight, terminal clusters.
Twig: Slender gray-green, covered with silvery hairs.
Bark: Light gray-brown with shallow fissures and darker ridges.
Form: A shrub with a rounded, dense crown reaching up to 3 feet in height.
Additional Range Information: Parthenium argentatum is native to North America. Range may be expanded by planting. See the full-size PDF map.
External Links: USDA Plants Database
All material © 2019 Virginia Tech Dept. of Forest Resources and Environmental Conservation; Photos and text by: John Seiler, Edward Jensen, Alex Niemiera, and John Peterson; Silvics reprinted from Ag Handbook 654; range map source information