TY - JOUR T1 - Leaves of the Helobiae JF - Botanical Gazette Y1 - 1921 A1 - Arber, Agnes SP - 31 EP - 38 KW - Alismataceae KW - Aponogetonaceae KW - Butomaceae KW - Hydrocharitaceae KW - Juncaginaceae KW - Naiadaceae KW - Potamogetonaceae VL - 72 UR - http://www.jstor.org/stable/2470114 IS - 1 ER -