[Covillea tridentata (Sessé & Moc. ex DC.) Vail, more]
Larrea tridentata is a resinous woody shrub and one of the most abundant components of North American deserts including the Chihuahuan Desert, and ranges into some of the lowest elevations of the Gila Region. The small paired leaflets, fused at their bases, are not symmetrical. The stipules, at first green, soon become reddish, and secrete copious resin. Stipules at the growing stem enclose and protect the young meristems (growing tip.) After a rain the aroma of terpenes from the wet foliage imparts a magical quality to the crisp desert air. The complex aromatic quality of the foliage has long been appreciated by local people for significant medicinal purposes, including inhalants and poultices, but should not be taken internally due to toxicity. The fruit is densely hairy and is the result of a five carpellate ovary that results in five indehiscent hairy nutlets.