Larrea tridentata (DC.) Coville
Creosote bush, chaparral
Creosote bush is an abundant native of arid parts of North America. These long-lived plants gradually spread out, with central portions dying and outlying portions eventually separating, forming clonal colonies. Taken together, these colonies are extremely long-lived. At 11,700 years old, the “King Clone” creosote colony is the oldest living organism on Earth.
Creosote was once harvested for its resin, which was used to create the original version of pressure treated lumber. Railroad ties and telephone poles immersed in boiling creostoe resin resist termiates, fungi, mites, and similar causes of wood rot.
Plants: Plants form irregular bushes up to 10' (3 m) high, but usually closer to half that; the size is proportional to the amount of available water. Plants give off a characteristic odor when wet or broken. Extremely deep root systems allow them to thrive in the arid environment.
Leaves: Leaves are yellow-green or dark green, resinous, and shiny, each consisting of two teardrop-shaped leaflets ½" (1.3 cm) long and ¼" (6.3 mm) wide. The two-leaflet leaves grow in opposite pairs, so it looks as if there are four tiny leaves at each node along the branch. Leaves are lanceolate.
Flowers: Yellow flowers are ¾-1" (1.9-2.5 cm) around, with five twisted petals.
Fruits: Seed pods are oval, surrounded by a silvery white fuzz, about ¼" (6.3 mm), comprised of five connected, one-seeded carpels which may come apart at maturity. They resemble pussy willows.
Edibility: Creosote is not edible. The creosote gall midge, a member of a set of closely related flies in the Asphondylia auripila group, produces variously shaped galls on creosote bushes. At least some of the galls produced by this and related flies are said to have produced a pleasurable experience when pulverized and smoked, originally by the Seri people.
Medical: Indigenous peoples relied on creosote as a sort of cure-all, using it for colds, stomach discomfort, as a pain killer, diuretic, anti-diarrheal, and for treatment of arthrtis, anemia, and sinusitis. I cannot find any support for these uses, however, and creosote is not even listed in the Physician’s Desk Reference for Herbal Medicines, a publication that descibes a wide range of real and purported herbal cures. This may be due to lack of study or lack of efficacy. Creosote is, however, antimicrobial, hence useful for treatment of cuts and bacterial or (possibly) fungal infections.
Larrea tridentata at the Mindbird Maps and Books unofficial Mojave National Preserve site
Larrea tridentata at Southeastern Arizona Wildflowers and the Plants of the Sonoran Desert
Larrea tridentata on Wikipedia
Larrea tridentata on cals.arizona.edu
Larrea tridentata on Wikimedia Commons
Larrea tridentata at the United States National Parks Service
Larrea tridentata at the Lady Bird Johnson Wildflower Center
Larrea tridentata on the USDA Forest Service's Fire Effects Information Database
Larrea tridentata on Vascular Plants of the Gila Wilderness
Larrea tridentata description by Thomas H. Kent, last updated 25 May 2020.