Wolffia columbiana H.Karst.

PLANTS OF OTTAWA DISTRICT
ONTARIO, CANADA
Wolffia columhlana Karsten
Tavistock Road, Woodroffe, Ottawa, Nepean
Township, Carleton County, Ont*
Floating on pond In marsh In pastureland
associated with W. punctata (16388), Lema
minor, L« trisulca and Suirodela polyrhiza.
DIVISION OF BOTANY, SCIENCE SERVICE
DEPARTMENT OF AGRICULTURE, OTTAWA, CANADA
03700865