Centaurea: from the Latin and a reference to the Centaur Chiron who was supposed to have discovered the medicinal uses of a plant in Greece that came to be called Centaury (contributed by Cynthia Powell)
calcitrapa: from the Latin calcitro, "to kick," caltrop, a four-pointed weapon usually positioned on the ground to impede enemy movements (contributed by Cynthia Powell)
Calflora:
Information on California plants for education, research and conservation,
with data contributed by
public and private institutions and individuals,
including the
Consortium of California Herbaria.[web application]. 2021. Berkeley, California:The Calflora Database
[a non-profit organization].Available:
https://www.calflora.org/(Accessed: 05/10/2021).
one or more occurrences