Guardiola diehlii

Guardiola diehlii is a very rare (quite possibly extinct) North American species of plants in the sunflower family, found only in the state of New Mexico in the southwestern United States.
"Guardiola diehlii" is (was) an annual herb up to tall. Leaves are long and narrow, up to long. One plant will produce several flower heads in a flat-topped array. Each head contains only one white ray flower and 4 disc flowers.