Vesper is a genus of flowering plants belonging to the family Apiaceae.

[1] Its native range is western and central USA to north-western Mexico.

It is found in the states of Arizona, California, Colorado, Idaho, Kansas, Nebraska, Nevada, New Mexico, Oklahoma, Oregon, South Dakota, Texas, Utah and Wyoming.

[1] The genus was circumscribed by Ronald Lee Hartmann and Guy L. Nesom in Phytoneuron 2012-94 on page 2 in 2012.

Their surnames combined are (Sun-down) and Vespers are prayers at sundown.