common spikeweed

<em>Centromadia pungens</em>, commonly known as the common spikeweed, is an annual herb in the family Asteraceae, native to California and Baja California in the western United States and northwestern Mexico. This species typically inhabits alkaline flats, vernal pool margins, grasslands, roadsides, and disturbed clay soils in the Central Valley and surrounding foothills of California. It is adapted to seasonally dry, often saline or alkaline conditions where competition from other plants is reduced. The species has not been evaluated under IUCN Red List criteria. <em>Centromadia pungens</em> is a highly spiny plant, with rigid, needle-tipped bracts surrounding its small yellow composite flower heads — an adaptation that deters herbivory. It grows to approximately 10–100 cm in height depending on conditions, often forming dense spiny mats in suitable habitat. While considered a native species of conservation interest in California due to habitat loss in the Central Valley, it is also regarded as a nuisance weed in some agricultural contexts. Biological traits such as average lifespan, body dimensions, and dietary specifics remain poorly documented in the scientific literature for this annual plant, though it typically completes its life cycle within a single growing season following winter rains.