Dwarf Bur Ragweed

The San Diego ambrosia is found in southern California from western Riverside County, south through western San Diego County, to central Baja California, Mexico. It inhabits coarse substrates near drainages and in upland areas on clay slopes, sparse grasslands, river terraces, pools, and alkali playas. It was listed as endangered in 2002, and ongoing threats to the species include development, non-native invasive plants, trampling, and mowing or discing associated with fuel modification and weed abatement activities. 

The San Diego ambrosia is a clonal herbaceous perennial plant in the family Asteraceae (sunflower). It spreads vegetatively by means of slender, branched, underground root-like rhizomes from which new above ground stems sprout each year after the winter rains. These stems generally grow 2 to 12 inches high, often forming mats characterized by pinnately divided gray-white leaves that are covered in short hairs. Stems may produce yellowish to greenish-colored flowers that appear from April to October. It produces separate male and female flowers on the same plant and is believed to be wind pollinated.?? The plant produces very few viable seeds, diminishing its ability to spread and colonize unoccupied areas.  

The San Diego ambrosia is a clonal herbaceous perennial plant in the family Asteraceae, which includes sunflowers. It spreads vegetatively by means of slender, branched, underground root-like rhizomes from which new above ground stems sprout each year after the winter rains. These stems generally grow 2 to 12 inches high, often forming mats characterized by pinnately divided gray-white leaves that are covered in short hairs. Stems may produce yellowish to greenish-colored flowers that appear from April to October.

It produces separate male and female flowers on the same plant and is believed to be wind pollinated.? The plant produces very few viable seeds, diminishing its ability to spread and colonize unoccupied areas.