Spirodela polyrhiza
PNW
BC
ID
MT
OR
WA
185 specimens from 20 herbaria:
British Columbia (25)
Idaho (25)
Montana (32)
Oregon (37)
Washington (66)
75 images from 17 herbaria:
CIC (3)
EWU (1)
HPSU (2)
ID (18)
IDS (1)
MONT (2)
MONTU (17)
NOCA (2)
PLU (2)
PSM (3)
RM (1)
SOC (2)
SRP (2)
UBC (3)
WCW (1)
WTU (11)
WWB (4)