Enneapogon cenchroides -- Arizona

Enneapogon cenchroides (soft feather pappusgrass) is an annual grass in the Poaceae family, native to arid and semi-arid regions of southern and western Africa and western Asia. This species has become naturalized in the United States, primarily in southern Arizona (the Ajo, Santa Catalina, Tucson, and Galiuro mountains), and is also expanding its invasive range in South America, with documented populations in Brazil. Enneapogon cenchroides is a relatively small annual, typically reaching up to a meter in height, that reproduces exclusively by seed rather than vegetatively, and its small, bristly propagules are capable of attaching to fur, clothing, and equipment, as well as dispersing by wind and water over long distances. This species is generally found in disturbed, arid, and semi-arid habitats, and there is evidence it can form dense stands and contribute to altered fire regimes alongside other invasive annuals and perennial species in the Sonoran Desert, such as Cenchrus ciliaris. There is a notable lack of peer-reviewed literature on the biology, phenology, and community-level ecological impacts of this species, and several evaluation answers relied on limited or indirect evidence; continued monitoring and further study are recommended given the species' apparent capacity for range expansion in climates similar to its native range.