Iva hayesiana is a rare species of flowering plant in the daisy family known by the common names San Diego marsh-elder and San Diego povertyweed. It is native to Baja California, and to California only in the vicinity of San Diego. This is a shrubby perennial herb approaching maximum heights near one meter. Its green oval-shaped leaves are fleshy, hairy, aromatic, and 3 to 6 centimeters long. The flowers are nearly invisible; male flowers have translucent corollas and simple yellow stamens and female flowers, if they occur, lacking corollas altogether. This is a plant of mineral-rich waterways such as intermittent streams and alkali flats.

Iva hayesiana is a fast spreading, aromatic evergreen plant that is a great choice for ground cover or bank stabilization. In nature, it's usually found in wetland flats or moister areas, but it's still fairly drought tolerant, and very tolerant to garden conditions. If used for bank stabilization on dry slopes, it needs occasional water, but in flats and sites that retain slightly more moisture, it needs no supplementary irrigation. Plant in sun or part shade.