mariposa lily
noun
mar·i·po·sa lily ˌmer-ə-ˈpō-zə- 
ˌma-rə-,
-sə-
: any of a genus (Calochortus) of western North American plants of the lily family with showy flowers having three petals and three sepals
called also mariposa tulip
compare sego lily
Example Sentences
Recent Examples on the Web Naturalist Ann Sarg suggests visiting the park to catch blooms in May, when natives like Nelson’s larkspur, nuttall violet, sand lilies, and mariposa lily bloom along paths like the Willow Creek trail. 
Sunset, 22 Jan. 2018
Sunset, 22 Jan. 2018 Word History
Etymology
probably from American Spanish mariposa, from Spanish, butterfly
First Known Use
1882, in the meaning defined above