Centaurea
nigra
PNW
BC
ID
MT
OR
WA
58 specimens from 12 herbaria:
British Columbia (13)
Idaho (5)
Montana (11)
Oregon (18)
Washington (11)
35 images from 10 herbaria:
HPSU (2)
IDE (5)
MONT (3)
MONTU (8)
OSC (5)
PSM (1)
SOC (1)
UBC (2)
WTU (6)
WWB (2)