Invasive ‘Stinknet’ Weed Poses Wildfire Threat in Sonoran Desert

The Sonoran Desert, renowned for its biodiversity, faces a growing threat from an invasive plant species known as stinknet.

Historically, wildfires have been rare in this region, primarily due to its unique ecological characteristics. However, stinknet, an aggressive invader, poses a serious risk to native plant life.

Also known as Oncosiphon pilulifer, stinknet is a low-growing weed that emits an unmistakable odor. Its flowering period typically occurs in March and April, with small spherical blooms ranging in color from yellow to gold. The leaves, resembling carrot tops, contribute to its pungent scent, often compared to dirty socks. As the plant matures and dries, it becomes highly flammable, further amplifying its threat.

Native to South Africa, stinknet was accidentally introduced to California in the 1980s and was first documented in Phoenix in 1997. By 2015, it had reached Tucson and is now classified as a Class B noxious weed in Arizona. Its rapid proliferation has gone largely unnoticed until recently.

Currently widespread in Maricopa County, stinknet is advancing into Pinal County, outcompeting local flora and disrupting ecosystems crucial for native wildlife.

In addition to its ecological impact, the dry, dead foliage of stinknet presents a significant fire hazard, threatening both human safety and local habitats. Moreover, the plant poses health risks including allergy aggravation and skin irritations.

The public can play a role in controlling the spread of stinknet. By inspecting outdoor gear and pets after hiking, individuals can help prevent the further dissemination of seeds. It is crucial to refrain from moving soil or plants from affected areas.

Identification is key. Stinknet is characterized by its spherical, petal-less flowers and distinctive odor. Similar-looking plants, such as pineapple weed and dogweed, have different scents and flower structures. When removing stinknet, wear gloves and ensure the plants are bagged to contain seeds.

While the persistence of stinknet is concerning, conservation efforts remain strong to protect the precious ecosystems of the Sonoran Desert.